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It’s the first—and only—opportunity I’ve ever had to participate in real science data collection. We all feel empowered. Turtle T.H.i.S. student intern
Field Moment: Gulf Island National Seashore; 19 October 2014, 1:12 a.m.; Turtle T.H.i.S.
A TEAM OF YOUTH VOLUNTEERS with Teens Helping in the Seashore, or “Turtle T.H.i.S.,” uses a photometer to measure ambient nighttime light levels near sea turtle nests at Gulf Islands National Seashore, Florida. The green laser beam helps the researchers target specific points for analysis. The red lights illuminating the work area are less disturbing to sea turtles and also preserve the team’s night vision because of their relatively short wavelength.
This program, which was formed in 2014 through a partnership with the National Park Foundation, the U.S. Geological Survey, and the NPS Natural Sounds and Night Skies Division, is part of a multifaceted sea turtle conservation effort along 160 miles (257 km) of undeveloped beaches that grace Gulf Islands. Four species of federally protected sea turtles nest at the park, including the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas), the leatherback sea turtle (Dermochelys coriacea), and the Kemp’s Ridley sea turtle (Lepidochelys kempii).
The goals of the project are to (1) document night sky brightness, which is one of the primary factors having a direct impact on sea turtle nesting, hatchling disorientation, and hatchling survival; (2) have students learn about the ecology of nesting and hatching sea turtles; and (3) provide NPS managers and community leaders with data to make relevant, science-based management decisions for the conservation of nesting sea turtles.
The project engages approximately 200 youth from local schools and colleges—including these students from Escambia High School in Pensacola, Florida—to help with data collection, management, analysis, and outreach. This photograph captures in an instant just how deeply the Turtle T.H.i.S. project engages the volunteers. Another student intern (not shown) reflected on the program, saying, “It’s the first—and only—opportunity I’ve ever had to participate in real science data collection. We all feel empowered.”
Download: PDF of this article
This article published
Online: 6 May 2016; In print: 25 March 2016
Shelley, D. C. 2016. Turtle T.H.i.S., Gulf Island National Seashore: 19 October 2014, 1:12 a.m. Park Science 32(2):79.
This page updated
5 May 2016
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Using microlensing -- an astronomical phenomenon and the only known method capable of discovering planets at great distances from the Earth -- the researchers were able to detect objects in extragalactic galaxies that range from the mass of the Moon to the mass of Jupiter, according to a press release by the US university.
Xinyu Dai, professor in the Homer L. Dodge Department of Physics and Astronomy in the College of Arts and Sciences, with postdoctoral researcher Eduardo Guerras, made the discovery with data from the National Aeronautics and Space Administration's Chandra X-ray Observatory.
"We are very excited about this discovery," said Dai. "These small planets are the best candidate for the signature we observed in this study using the microlensing technique."
The university claimed that there has been no evidence of planets in other galaxies until this study. | <urn:uuid:ea4f1e7a-baac-4deb-825d-1344940aa832> | 3.15625 | 175 | News Article | Science & Tech. | 23.25033 | 95,488,615 |
New Super Slippery Surface Better Than Nature's
Penn State researchers have developed new highly slippery surfaces that do better than natural surfaces like the leaves of the lotus flower.
(New slippery rough surface)
Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient water harvesting in arid regions, and prevent icing and frosting on aircraft wings. "This represents a fundamentally new concept in engineered surfaces," said Tak-Sing Wong, assistant professor of mechanical engineering and a faculty member in the Penn State Materials Research Institute. "Our surfaces combine the unique surface architectures of lotus leaves and pitcher plants in such a way that these surfaces possess both high surface area and a slippery interface to enhance droplet collection and mobility. Mobility of liquid droplets on rough surfaces is highly dependent on how the liquid wets the surface. We have demonstrated for the first time experimentally that liquid droplets can be highly mobile when in the Wenzel state."
Fans of Frank Herbert's Dune technology, from his 1965 novel Dune recall that the Fremen used similar technology:
A splashing sounded on her left. She looked down the shadowy line of Fremen, saw Stilgar with Paul standing beside him and the watermasters emptying their load into the pool through a flowmeter. ...
Superb accuracy in water measurement, Jessica thought. And she noted that the walls of the meter trough held no trace of moisture after the water's passage. The water flowed off those walls without binding tension. She saw a profound clue to Fremen technology in the simple fact: they were perfectionists.
(Read more about Frank Herbert's water repellent surface from Dune
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So what is a game engine? A game engine is a software (library) that provides game creators tools & features they need to create a game efficiently. Powerful engines like Unreal engine, Cryengine and Unity are examples of great tools that will make games bigger and better.
Programming language for game development ~ Gaming industries is growing so fast this decade. Starting from the PlayStation 1 in 1994 to the PlayStation 4 in the present day. Not to mention Xbox, Nintendo and other kinds of consoles. And the PC with steam that has over than 5000 games with varieties of genres that’s available for all of us to enjoy(including the good and the bad).
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In mathematics, computable numbers are the real numbers that can be computed to within any desired precision by a finite, terminating algorithm. They are also known as the recursive numbers or the computable reals or recursive reals.
Equivalent definitions can be given using μ-recursive functions, Turing machines, or λ-calculus as the formal representation of algorithms. The computable numbers form a real closed field and can be used in the place of real numbers for many, but not all, mathematical purposes.
Informal definition using a Turing machine as exampleEdit
In the following, Marvin Minsky defines the numbers to be computed in a manner similar to those defined by Alan Turing in 1936; i.e., as "sequences of digits interpreted as decimal fractions" between 0 and 1:
- "A computable number [is] one for which there is a Turing machine which, given n on its initial tape, terminates with the nth digit of that number [encoded on its tape]." (Minsky 1967:159)
The key notions in the definition are (1) that some n is specified at the start, (2) for any n the computation only takes a finite number of steps, after which the machine produces the desired output and terminates.
An alternate form of (2) – the machine successively prints all n of the digits on its tape, halting after printing the nth – emphasizes Minsky's observation: (3) That by use of a Turing machine, a finite definition – in the form of the machine's table – is being used to define what is a potentially-infinite string of decimal digits.
This is however not the modern definition which only requires the result be accurate to within any given accuracy. The informal definition above is subject to a rounding problem called the table-maker's dilemma whereas the modern definition is not.
There are two similar definitions that are equivalent:
- There exists a computable function which, given any positive rational error bound , produces a rational number r such that
- There is a computable sequence of rational numbers converging to such that for each i.
There is another equivalent definition of computable numbers via computable Dedekind cuts. A computable Dedekind cut is a computable function which when provided with a rational number as input returns or , satisfying the following conditions:
An example is given by a program D that defines the cube root of 3. Assuming this is defined by:
A real number is computable if and only if there is a computable Dedekind cut D converging to it. The function D is unique for each computable number (although of course two different programs may provide the same function).
A complex number is called computable if its real and imaginary parts are computable.
Countable but not computably enumerableEdit
While the set of real numbers is uncountable, the set of computable numbers is only countable and thus almost all real numbers are not computable. That the computable numbers are at most countable intuitively comes from the fact that they are produced by Turing machines, of which there are only countably many. More precisely, assigning a Gödel number to each Turing machine definition produces a subset of the natural numbers corresponding to the computable numbers and identifies a surjection from to the computable numbers, which shows that the computable numbers are subcountable. Moreover, for any computable number the well ordering principle provides that there is a minimal element in which corresponds to , and therefore there exists a subset consisting of the minimal elements, on which the map is a bijection. The inverse of this bijection is an injection into the natural numbers of the computable numbers, proving that they are countable.
The set of these Gödel numbers, however, is not computably enumerable (nor consequently is ), even though the computable reals are themselves ordered. This is because there is no algorithm to determine which Gödel numbers correspond to Turing machines that produce computable reals. In order to produce a computable real, a Turing machine must compute a total function, but the corresponding decision problem is in Turing degree 0′′. Consequently, there is no surjective computable function from the natural numbers to the computable reals, and Cantor's diagonal argument cannot be used constructively to demonstrate uncountably many of them.
Properties as a fieldEdit
The arithmetical operations on computable numbers are themselves computable in the sense that whenever real numbers a and b are computable then the following real numbers are also computable: a + b, a - b, ab, and a/b if b is nonzero. These operations are actually uniformly computable; for example, there is a Turing machine which on input (A,B, ) produces output r, where A is the description of a Turing machine approximating a, B is the description of a Turing machine approximating b, and r is an approximation of a+b.
The fact that computable real numbers form a field was first proved by Henry Gordon Rice (1954).
Computable reals do not form however a computable field, because the definition of the latter notion requires effective equality.
Non-computability of the orderingEdit
The order relation on the computable numbers is not computable. Let A be the description of a Turing machine approximating the number . Then there is no Turing machine which on input A outputs "YES" if and "NO" if . The reason: suppose the machine described by A keeps outputting 0 as approximations. It is not clear how long to wait before deciding that the machine will never output an approximation which forces a to be positive. Thus the machine will eventually have to guess that the number will equal 0, in order to produce an output; the sequence may later become different from 0. This idea can be used to show that the machine is incorrect on some sequences if it computes a total function. A similar problem occurs when the computable reals are represented as Dedekind cuts. The same holds for the equality relation : the equality test is not computable.
While the full order relation is not computable, the restriction of it to pairs of unequal numbers is computable. That is, there is a program that takes as input two Turing machines A and B approximating numbers a and b, where a ≠ b, and outputs whether or . It is sufficient to use ε-approximations where so by taking increasingly small ε (with a limit to 0), one eventually can decide whether or .
The computable real numbers do not share all the properties of the real numbers used in analysis. For example, the least upper bound of a bounded increasing computable sequence of computable real numbers need not be a computable real number (Bridges and Richman, 1987:58). A sequence with this property is known as a Specker sequence, as the first construction is due to E. Specker (1949). Despite the existence of counterexamples such as these, parts of calculus and real analysis can be developed in the field of computable numbers, leading to the study of computable analysis.
Every computable number is definable, but not vice versa. There are many definable, noncomputable real numbers, including:
- any number that encodes the solution of the halting problem (or any other undecidable problem) according to a chosen encoding scheme.
- Chaitin's constant, , which is a type of real number that is Turing equivalent to the halting problem.
Both of these examples in fact define an infinite set of definable, uncomputable numbers, one for each Universal Turing machine. A real number is computable if and only if the set of natural numbers it represents (when written in binary and viewed as a characteristic function) is computable.
Every computable number is arithmetical.
Digit strings and the Cantor and Baire spacesEdit
Turing's original paper defined computable numbers as follows:
- A real number is computable if its digit sequence can be produced by some algorithm or Turing machine. The algorithm takes an integer as input and produces the -th digit of the real number's decimal expansion as output.
(Note that the decimal expansion of a only refers to the digits following the decimal point.)
Turing was aware that this definition is equivalent to the -approximation definition given above. The argument proceeds as follows: if a number is computable in the Turing sense, then it is also computable in the sense: if , then the first n digits of the decimal expansion for a provide an approximation of a. For the converse, we pick an computable real number a and generate increasingly precise approximations until the nth digit after the decimal point is certain. This always generates a decimal expansion equal to a but it may improperly end in an infinite sequence of 9's in which case it must have a finite (and thus computable) proper decimal expansion.
Unless certain topological properties of the real numbers are relevant it is often more convenient to deal with elements of (total 0,1 valued functions) instead of reals numbers in . The members of can be identified with binary decimal expansions but since the decimal expansions and denote the same real number the interval can only be bijectively (and homeomorphically under the subset topology) identified with the subset of not ending in all 1's.
Note that this property of decimal expansions means it's impossible to effectively identify computable real numbers defined in terms of a decimal expansion and those defined in the approximation sense. Hirst has shown there is no algorithm which takes as input the description of a Turing machine which produces approximations for the computable number a, and produces as output a Turing machine which enumerates the digits of a in the sense of Turing's definition (see Hirst 2007). Similarly it means that the arithmetic operations on the computable reals are not effective on their decimal representations as when adding decimal numbers, in order to produce one digit it may be necessary to look arbitrarily far to the right to determine if there is a carry to the current location. This lack of uniformity is one reason that the contemporary definition of computable numbers uses approximations rather than decimal expansions.
However, from a computational or measure theoretic perspective the two structures and are essentially identical, and computability theorists often refer to members of as reals. While is totally disconnected for questions about classes or randomness it's much less messy to work in .
Elements of are sometimes called reals as well and though containing a homeomorphic image of in addition to being totally disconnected isn't even locally compact. This leads to genuine differences in the computational properties. For instance the satisfying with quantifier free must be computable while the unique satisfying a universal formula can be arbitrarily high in the hyperarithmetic hierarchy.
Can computable numbers be used instead of the reals?Edit
The computable numbers include many of the specific real numbers which appear in practice, including all real algebraic numbers, as well as e, , and many other transcendental numbers. Though the computable reals exhaust those reals we can calculate or approximate, the assumption that all reals are computable leads to substantially different conclusions about the real numbers. The question naturally arises of whether it is possible to dispose of the full set of reals and use computable numbers for all of mathematics. This idea is appealing from a constructivist point of view, and has been pursued by what Bishop and Richman call the Russian school of constructive mathematics.
To actually develop analysis over computable numbers, some care must be taken. For example, if one uses the classical definition of a sequence, the set of computable numbers is not closed under the basic operation of taking the supremum of a bounded sequence (for example, consider a Specker sequence). This difficulty is addressed by considering only sequences which have a computable modulus of convergence. The resulting mathematical theory is called computable analysis.
- Oliver Aberth 1968, Analysis in the Computable Number Field, Journal of the Association for Computing Machinery (JACM), vol 15, iss 2, pp 276–299. This paper describes the development of the calculus over the computable number field.
- Errett Bishop and Douglas Bridges, Constructive Analysis, Springer, 1985, ISBN 0-387-15066-8
- Douglas Bridges and Fred Richman. Varieties of Constructive Mathematics, Oxford, 1987.
- Jeffry L. Hirst, Representations of reals in reverse mathematics, Bulletin of the Polish Academy of Sciences, Mathematics, 55, (2007) 303–316.
- Marvin Minsky 1967, Computation: Finite and Infinite Machines, Prentice-Hall, Inc. Englewood Cliffs, NJ. No ISBN. Library of Congress Card Catalog No. 67-12342. His chapter §9 "The Computable Real Numbers" expands on the topics of this article.
- E. Specker, "Nicht konstruktiv beweisbare Sätze der Analysis" J. Symbol. Logic, 14 (1949) pp. 145–158
- Turing, A.M. (1936), "On Computable Numbers, with an Application to the Entscheidungsproblem", Proceedings of the London Mathematical Society, 2 (published 1937), 42 (1), pp. 230–65, doi:10.1112/plms/s2-42.1.230 (and Turing, A.M. (1938), "On Computable Numbers, with an Application to the Entscheidungsproblem: A correction", Proceedings of the London Mathematical Society, 2 (published 1937), 43 (6), pp. 544–6, doi:10.1112/plms/s2-43.6.544). Computable numbers (and Turing's a-machines) were introduced in this paper; the definition of computable numbers uses infinite decimal sequences.
- Klaus Weihrauch 2000, Computable analysis, Texts in theoretical computer science, Springer, ISBN 3-540-66817-9. §1.3.2 introduces the definition by nested sequences of intervals converging to the singleton real. Other representations are discussed in §4.1.
- Klaus Weihrauch, A simple introduction to computable analysis
- H. Gordon Rice. "Recursive real numbers." Proceedings of the American Mathematical Society 5.5 (1954): 784-791.
- V. Stoltenberg-Hansen, J. V. Tucker "Computable Rings and Fields" in Handbook of computability theory edited by E.R. Griffor. Elsevier 1999
Computable numbers were defined independently by Turing, Post and Church. See The Undecidable, ed. Martin Davis, for further original papers. | <urn:uuid:9e8051a1-3e11-43f5-8320-506783c37741> | 4.09375 | 3,082 | Knowledge Article | Science & Tech. | 34.590608 | 95,488,689 |
The study also is the first to indicate that at least a few bird species opt for noisy areas over quiet ones, perhaps because of their vocalization pitches, a reduction in nest predators and less competition from other songbirds that prefer quiet environments.
The three-year study compared nesting birds inhabiting pinyon-juniper woodland sites surrounding natural gas extraction sites and their noise-producing compressors with birds nesting in adjacent, quieter woodland sites. While bird species richness declined at noisy sites, the bird nesting success was higher there than in the nearby quiet sites, said CU-Boulder doctoral candidate Clinton Francis, lead author on a study published online July 23 in Current Biology.
"This is the first study to show that noise pollution causes changes in species interactions within bird communities," said Francis of CU-Boulder's Department of Ecology and Evolutionary Biology. "Since noise pollution can be a major cause of declining bird diversity in and around urban areas, better noise control using quieter road surfaces and sound-reducing walls and berms should be considered to help preserve such communities."
Co-authors on the Current Biology study included CU-Boulder Professor Alex Cruz and Fort Lewis College faculty member Catherine Ortega, who received her doctorate from CU-Boulder under Cruz. The study was conducted in a parcel of woodland south of Durango, Colo., just over the New Mexico border.
While other studies have shown noise pollution can have negative impacts on bird species, most have been conducted near heavily used roads, said Francis. The CU-Boulder study is one of the first conducted in a controlled environment -- the team worked with energy companies to shut down gas pad compressors for several hours each week, allowing researchers to identify individual nests and determine nesting success.
The researchers found that 32 different bird species nested in the quiet areas undisturbed by noise pollution, while only 21 species were nesting in the noisy study sites. The team also found only three bird species nested exclusively at the noisy sites, while 14 different bird species nested only in the quiet sites, said Francis.
Two bird species preferred the noisy sites, he said. Ninety-two percent of the black-chinned hummingbird nests and 94 percent of house finch nests in the two study areas were found at sites near noisy compressors. The two species accounted for 31 percent of the nests at the noisy sites, but less than 3 percent on the quiet sites, said Francis.
Francis said house finches and black-chinned hummingbirds produce vocalizations at higher acoustic frequencies than those generated by compressors, which may allow them to communicate above the "industrial rumble" and subsequently nest there, he said. Common in congested urban areas, house finches also are known to sing at higher frequencies in response to urban noise, said Francis.
Higher nesting success at noisy sites by house finches, black-chinned hummingbirds and of other species was due to lower levels of predation by a major nemesis of the birds -- the western scrub jay -- which was shown to prefer the quiet woodland sites.
Western scrub jays, which are known to prey on eggs and young of songbirds, play a key role in Southwest woodland ecology, said Francis. They were shown to be 32 percent more common in the quiet areas, perhaps in part because some of their vocalizations were in the same range as the compressor noise and inhibited communication.
Since scrub jays frequently carry, eat and cache pine nuts and disperse them throughout Southwest woodland areas, a decrease in scrub jays in such areas could result in the decreased establishment of pinyon pine. This would potentially affect many organisms and alter the dynamics of the ecological community, said Francis.
The team determined that 97 percent of mourning dove nests and 100 percent of black-headed grosbeak nests in the study area were found in the quiet areas away from the din of compressors. Francis said the low vocal frequencies of mourning doves and black-headed grosbeaks appear to overlap with most human-caused noises, which may inhibit vocal communication required for repelling rivals, pairing and nesting.
The study indicated birds that were intolerant of noise and nested in quiet areas were subject to greater rate of nest predation than those in noisy areas, he said. Woodland birds that prefer noisy areas may even use the clamor of civilization as cues for nesting, since such noise might signal a reduction in potential predators.
The researchers also found that a number of bird species found in the noisy sites -- including gray flycatchers, gray vireos, black-throated gray warblers and spotted towhees -- tended to avoid areas of noise disturbance when selecting nesting sites.
"Understanding how birds respond to noise, especially birds with critical links to ecosystems, are crucial in maintaining biodiversity in growing areas of landscapes disturbed by urban clamor," said Francis.
The study was funded by a number of organizations, including the Bureau of Land Management and the University of Colorado.
Clinton Francis | EurekAlert!
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A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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El Ghawaby, M.A.
Remote sensing techniques are quite dependable tools in investigating geologic problems, specially those related to structural aspects. The Landsat imagery provides discrimination between rock units, detection of large scale structures as folds and faults, as well as small scale fabric elements such as foliation and banding. In order to fulfill the aim of geologic application of remote sensing, some essential surveying maps might be done from images prior to the structural interpretation: land-use, land-form drainage pattern, lithological unit and structural lineament maps. Afterwards, the field verification should lead to interpretation of a comprehensive structural model of the study area to apply for the target problem. To deduce such a model, there are two ways of analysis the interpreter may go through: the direct and the indirect methods. The direct one is needed in cases where the resources or the targets are controlled by an obvious or exposed structural element or pattern. The indirect way is necessary for areas where the target is governed by a complicated structural pattern. Some case histories of structural modelling methods applied successfully for exploration of radioactive minerals, iron deposits and groundwater aquifers in Egypt are presented. The progress in imagery, enhancement and integration of remote sensing data with the other geophysical and geochemical data allow a geologic interpretation to be carried out which become better than that achieved with either of the individual data sets. 9 refs
A GIS AND REMOTE SENSING APPROACH TO ASSESSMENT OF DEFORESTATION IN ... This study measured and analyzed deforestation in Uyo and examined the possible effects of the ..... the Burkill technique, (1985, 1994, 1995, 1997.
Khorram, Siamak; Koch, Frank H; van der Wiele, Cynthia F
Remote Sensing provides information on how remote sensing relates to the natural resources inventory, management, and monitoring, as well as environmental concerns. It explains the role of this new technology in current global challenges. "Remote Sensing" will discuss remotely sensed data application payloads and platforms, along with the methodologies involving image processing techniques as applied to remotely sensed data. This title provides information on image classification techniques and image registration, data integration, and data fusion techniques. How this technology applies to natural resources and environmental concerns will also be discussed.
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National Aeronautics and Space Administration — MULTI-TEMPORAL REMOTE SENSING IMAGE CLASSIFICATION - A MULTI-VIEW APPROACH VARUN CHANDOLA AND RANGA RAJU VATSAVAI Abstract. Multispectral remote sensing images have...
DTC) algorithm for classification of remotely sensed satellite data (Landsat TM) using open source support. The decision tree is constructed by recursively partitioning the spectral distribution of the training dataset using WEKA, open source ...
remote sensing data for Uyo for the periods 1969, 1978, 1988, 2001 and 2004; evaluate the ... geographical information system (GIS) technology was applied to carry out this research. Field ..... preventing erosion, landslides, and making the.
Campbell, W. J.; Ramseier, R. O.; Weeks, W. F.; Gloersen, P.
Review article on remote sensing applications to glaciology. Ice parameters sensed include: ice cover vs open water, ice thickness, distribution and morphology of ice formations, vertical resolution of ice thickness, ice salinity (percolation and drainage of brine; flushing of ice body with fresh water), first-year ice and multiyear ice, ice growth rate and surface heat flux, divergence of ice packs, snow cover masking ice, behavior of ice shelves, icebergs, lake ice and river ice; time changes. Sensing techniques discussed include: satellite photographic surveys, thermal IR, passive and active microwave studies, microwave radiometry, microwave scatterometry, side-looking radar, and synthetic aperture radar. Remote sensing of large aquatic mammals and operational ice forecasting are also discussed.
Ronald E. McRoberts
Multiple remote sensing-based approaches to estimating gross afforestation, gross deforestation, and net deforestation are possible. However, many of these approaches have severe data requirements in the form of long time series of remotely sensed data and/or large numbers of observations of land cover change to train classifiers and assess the accuracy of...
Cracknell, Arthur P
Addressing the need for updated information in remote sensing, Introduction to Remote Sensing, Second Edition provides a full and authoritative introduction for scientists who need to know the scope, potential, and limitations in the field. The authors discuss the physical principles of common remote sensing systems and examine the processing, interpretation, and applications of data. This new edition features updated and expanded material, including greater coverage of applications from across earth, environmental, atmospheric, and oceanographic sciences. Illustrated with remotely sensed colo
sensed satellite data using open source support. Richa Sharma .... Decision tree classification techniques have been .... the USGS Earth Resource Observation Systems. (EROS) ... for shallow water, 11% were for sparse and dense built-up ...
Gao, J.; Lythe, M. B.
This paper presents the principle of the Maximum Cross-Correlation (MCC) approach in detecting translational motions within dynamic fields from time-sequential remotely sensed images. A C program implementing the approach is presented and illustrated in a flowchart. The program is tested with a pair of sea-surface temperature images derived from Advanced Very High Resolution Radiometer (AVHRR) images near East Cape, New Zealand. Results show that the mean currents in the region have been detected satisfactorily with the approach.
Mendiguren, Gorka; Koch, Julian; Stisen, Simon
Distributed hydrological models are traditionally evaluated against discharge stations, emphasizing the temporal and neglecting the spatial component of a model. The present study widens the traditional paradigm by highlighting spatial patterns of evapotranspiration (ET), a key variable at the land-atmosphere interface, obtained from two different approaches at the national scale of Denmark. The first approach is based on a national water resources model (DK-model), using the MIKE-SHE model code, and the second approach utilizes a two-source energy balance model (TSEB) driven mainly by satellite remote sensing data. Ideally, the hydrological model simulation and remote-sensing-based approach should present similar spatial patterns and driving mechanisms of ET. However, the spatial comparison showed that the differences are significant and indicate insufficient spatial pattern performance of the hydrological model.The differences in spatial patterns can partly be explained by the fact that the hydrological model is configured to run in six domains that are calibrated independently from each other, as it is often the case for large-scale multi-basin calibrations. Furthermore, the model incorporates predefined temporal dynamics of leaf area index (LAI), root depth (RD) and crop coefficient (Kc) for each land cover type. This zonal approach of model parameterization ignores the spatiotemporal complexity of the natural system. To overcome this limitation, this study features a modified version of the DK-model in which LAI, RD and Kc are empirically derived using remote sensing data and detailed soil property maps in order to generate a higher degree of spatiotemporal variability and spatial consistency between the six domains. The effects of these changes are analyzed by using empirical orthogonal function (EOF) analysis to evaluate spatial patterns. The EOF analysis shows that including remote-sensing-derived LAI, RD and Kc in the distributed hydrological model adds
Full Text Available Schistosomiasis is a widespread water-based disease that puts close to 800 million people at risk of infection with more than 250 million infected, mainly in sub-Saharan Africa. Transmission is governed by the spatial distribution of specific freshwater snails that act as intermediate hosts and the frequency, duration and extent of human bodies exposed to infested water sources during human water contact. Remote sensing data have been utilized for spatially explicit risk profiling of schistosomiasis. Since schistosomiasis risk profiling based on remote sensing data inherits a conceptual drawback if school-based disease prevalence data are directly related to the remote sensing measurements extracted at the location of the school, because the disease transmission usually does not exactly occur at the school, we took the local environment around the schools into account by explicitly linking ecologically relevant environmental information of potential disease transmission sites to survey measurements of disease prevalence. Our models were validated at two sites with different landscapes in Côte d’Ivoire using high- and moderateresolution remote sensing data based on random forest and partial least squares regression. We found that the ecologically relevant modelling approach explained up to 70% of the variation in Schistosoma infection prevalence and performed better compared to a purely pixelbased modelling approach. Furthermore, our study showed that model performance increased as a function of enlarging the school catchment area, confirming the hypothesis that suitable environments for schistosomiasis transmission rarely occur at the location of survey measurements.
Prasad, Saurabh; Chanussot, Jocelyn
Optical remote sensing relies on exploiting multispectral and hyper spectral imagery possessing high spatial and spectral resolutions respectively. These modalities, although useful for most remote sensing tasks, often present challenges that must be addressed for their effective exploitation. This book presents current state-of-the-art algorithms that address the following key challenges encountered in representation and analysis of such optical remotely sensed data: challenges in pre-processing images, storing and representing high dimensional data, fusing different sensor modalities, patter
remote sensing from satellites. Sensing of oceanographic variables from aircraft began with the photographing of waves and ice. Since then remote measurement of sea surface temperatures and wave heights have become routine. Sensors tested for oceanographic applications include multi-band color cameras, radar scatterometers, infrared spectrometers and scanners, passive microwave radiometers, and radar imagers. Remote sensing has found its greatest application in providing rapid coverage of large oceanographic areas for synoptic and analysis and
Slonecker, Terrence; Jones, John W.; Price, Susan D.; Hogan, Dianna
'Remote sensing' is a generic term for monitoring techniques that collect information without being in physical contact with the object of study. Overhead imagery from aircraft and satellite sensors provides the most common form of remotely sensed data and records the interaction of electromagnetic energy (usually visible light) with matter, such as the Earth's surface. Remotely sensed data are fundamental to geographic science. The Eastern Geographic Science Center (EGSC) of the U.S. Geological Survey (USGS) is currently conducting and promoting the research and development of three different aspects of remote sensing science: spectral analysis, automated orthorectification of historical imagery, and long wave infrared (LWIR) polarimetric imagery (PI).
Federal Laboratory Consortium — The Optical Remote Sensing Laboratory deploys rugged, cutting-edge electro-optical instrumentation for the collection of various event signatures, with expertise in...
Mui, Amy B.
Freshwater turtles are a globally declining taxa, and estimates of population status are not available for many species. Primary causes of decline stem from widespread habitat loss and degradation, and obtaining spatially-explicit information on remaining habitat across a relevant spatial scale has proven challenging. The discipline of remote sensing science has been employed widely in studies of biodiversity conservation, but it has not been utilized as frequently for cryptic, and less vagile species such as turtles, despite their vulnerable status. The work presented in this thesis investigates how multi-temporal remote sensing imagery can contribute key information for building spatially-explicit and temporally dynamic models of habitat and connectivity for the threatened, Blanding's turtle (Emydoidea blandingii) in southern Ontario, Canada. I began with outlining a methodological approach for delineating freshwater wetlands from high spatial resolution remote sensing imagery, using a geographic object-based image analysis (GEOBIA) approach. This method was applied to three different landscapes in southern Ontario, and across two biologically relevant seasons during the active (non-hibernating) period of Blanding's turtles. Next, relevant environmental variables associated with turtle presence were extracted from remote sensing imagery, and a boosted regression tree model was developed to predict the probability of occurrence of this species. Finally, I analysed the movement potential for Blanding's turtles in a disturbed landscape using a combination of approaches. Results indicate that (1) a parsimonious GEOBIA approach to land cover mapping, incorporating texture, spectral indices, and topographic information can map heterogeneous land cover with high accuracy, (2) remote-sensing derived environmental variables can be used to build habitat models with strong predictive power, and (3) connectivity potential is best estimated using a variety of approaches
Full Text Available Multipurpose small reservoirs are important for livelihoods in rural semi-arid regions. To manage and plan these reservoirs and to assess their hydrological impact at a river basin scale, it is important to monitor their water storage dynamics. This paper introduces a Bayesian approach for monitoring small reservoirs with radar satellite images. The newly developed growing Bayesian classifier has a high degree of automation, can readily be extended with auxiliary information and reduces the confusion error to the land-water boundary pixels. A case study has been performed in the Upper East Region of Ghana, based on Radarsat-2 data from November 2012 until April 2013. Results show that the growing Bayesian classifier can deal with the spatial and temporal variability in synthetic aperture radar (SAR backscatter intensities from small reservoirs. Due to its ability to incorporate auxiliary information, the algorithm is able to delineate open water from SAR imagery with a low land-water contrast in the case of wind-induced Bragg scattering or limited vegetation on the land surrounding a small reservoir.
Rajchandar Padmanaban; Avit K. Bhowmik; Pedro Cabral
Padmanaban, R., Bhowmik, A. K., & Cabral, P. (2017). A Remote Sensing Approach to Environmental Monitoring in a Reclaimed Mine Area. ISPRS International Journal of Geo-Information, 6(12), 1-14. . DOI: 10.3390/ijgi6120401 Mining for resources extraction may lead to geological and associated environmental changes due to ground movements, collision with mining cavities, and deformation of aquifers. Geological changes may continue in a reclaimed mine area, and the deformed aquifers may en...
Covers several hot topics in current research of electromagnetic scattering, and radiative transfer in complex and random media, polarimetric scattering and SAR imagery technology, data validation and information retrieval from space-borne remote sensing, computational electromagnetics, etc.Including both forward modelling and inverse problems, analytic theory and numerical approachesAn overall summary of the author's works during most recent yearsAlso presents some insight for future research topics.
Hyperspectral remote sensing is an emerging, multidisciplinary field with diverse applications that builds on the principles of material spectroscopy, radiative transfer, imaging spectrometry, and hyperspectral data processing. This book provides a holistic treatment that captures its multidisciplinary nature, emphasizing the physical principles of hyperspectral remote sensing.
Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.
Eismann, Michael Theodore
..., and hyperspectral data processing. While there are many resources that suitably cover these areas individually and focus on specific aspects of the hyperspectral remote sensing field, this book provides a holistic treatment...
Schweitzer, Jeffrey S.; Groves, Joel L.
Subsurface remote sensing measurements are widely used for oil and gas exploration, for oil and gas production monitoring, and for basic studies in the earth sciences. Radiation sensors, often including small accelerator sources, are used to obtain bulk properties of the surrounding strata as well as to provide detailed elemental analyses of the rocks and fluids in rock pores. Typically, instrument packages are lowered into a borehole at the end of a long cable, that may be as long as 10 km, and two-way data and instruction telemetry allows a single radiation instrument to operate in different modes and to send the data to a surface computer. Because these boreholes are often in remote locations throughout the world, the data are frequently transmitted by satellite to various locations around the world for almost real-time analysis and incorporation with other data. The complete system approach that permits rapid and reliable data acquisition, remote analysis and transmission to those making decisions is described
Kazem Alavipanah, Seyed
There are some problems in soil salinity studies based upon remotely sensed data: 1-spectral world is full of ambiguity and therefore soil reflectance can not be attributed to a single soil property such as salinity, 2) soil surface conditions as a function of time and space is a complex phenomena, 3) vegetation with a dynamic biological nature may create some problems in the study of soil salinity. Due to these problems the first question which may arise is how to overcome or minimise these problems. In this study we hypothesised that different sources of data, well established sampling plan and optimum approach could be useful. In order to choose representative training sites in the Iranian playa margins, to define the spectral and informational classes and to overcome some problems encountered in the variation within the field, the following attempts were made: 1) Principal Component Analysis (PCA) in order: a) to determine the most important variables, b) to understand the Landsat satellite images and the most informative components, 2) the photomorphic unit (PMU) consideration and interpretation; 3) study of salt accumulation and salt distribution in the soil profile, 4) use of several forms of field data, such as geologic, geomorphologic and soil information; 6) confirmation of field data and land cover types with farmers and the members of the team. The results led us to find at suitable approaches with a high and acceptable image classification accuracy and image interpretation. KEY WORDS; Photo Morphic Unit, Pprincipal Ccomponent Analysis, Soil Salinity, Field Work, Remote Sensing
Juan M Requena-Mullor
Full Text Available As climate change is expected to have a significant impact on species distributions, there is an urgent challenge to provide reliable information to guide conservation biodiversity policies. In addressing this challenge, we propose a remote sensing-based approach to forecast the future habitat quality for European badger, a species not abundant and at risk of local extinction in the arid environments of southeastern Spain, by incorporating environmental variables related with the ecosystem functioning and correlated with climate and land use. Using ensemble prediction methods, we designed global spatial distribution models for the distribution range of badger using presence-only data and climate variables. Then, we constructed regional models for an arid region in the southeast Spain using EVI (Enhanced Vegetation Index derived variables and weighting the pseudo-absences with the global model projections applied to this region. Finally, we forecast the badger potential spatial distribution in the time period 2071-2099 based on IPCC scenarios incorporating the uncertainty derived from the predicted values of EVI-derived variables. By including remotely sensed descriptors of the temporal dynamics and spatial patterns of ecosystem functioning into spatial distribution models, results suggest that future forecast is less favorable for European badgers than not including them. In addition, change in spatial pattern of habitat suitability may become higher than when forecasts are based just on climate variables. Since the validity of future forecast only based on climate variables is currently questioned, conservation policies supported by such information could have a biased vision and overestimate or underestimate the potential changes in species distribution derived from climate change. The incorporation of ecosystem functional attributes derived from remote sensing in the modeling of future forecast may contribute to the improvement of the
Alparone, Luciano; Baronti, Stefano; Garzelli, Andrea
A synthesis of more than ten years of experience, Remote Sensing Image Fusion covers methods specifically designed for remote sensing imagery. The authors supply a comprehensive classification system and rigorous mathematical description of advanced and state-of-the-art methods for pansharpening of multispectral images, fusion of hyperspectral and panchromatic images, and fusion of data from heterogeneous sensors such as optical and synthetic aperture radar (SAR) images and integration of thermal and visible/near-infrared images. They also explore new trends of signal/image processing, such as
Campbell, James B
A leading text for undergraduate- and graduate-level courses, this book introduces widely used forms of remote sensing imagery and their applications in plant sciences, hydrology, earth sciences, and land use analysis. The text provides comprehensive coverage of principal topics and serves as a framework for organizing the vast amount of remote sensing information available on the Web. Including case studies and review questions, the book's four sections and 21 chapters are carefully designed as independent units that instructors can select from as needed for their courses. Illustrations in
Rosen, Paul A.
This lecture was just a taste of radar remote sensing techniques and applications. Other important areas include Stereo radar grammetry. PolInSAR for volumetric structure mapping. Agricultural monitoring, soil moisture, ice-mapping, etc. The broad range of sensor types, frequencies of observation and availability of sensors have enabled radar sensors to make significant contributions in a wide area of earth and planetary remote sensing sciences. The range of applications, both qualitative and quantitative, continue to expand with each new generation of sensors.
Full Text Available The extension and frequency of algal blooms in surface waters can be monitored using remote sensing techniques, yet knowledge of their vertical distribution is fundamental to determine total phytoplankton biomass and understanding temporal variability of surface conditions and the underwater light field. However, different vertical distribution classes of phytoplankton may occur in complex inland lakes. Identification of the vertical profile classes of phytoplankton becomes the key and first step to estimate its vertical profile. The vertical distribution profile of phytoplankton is based on a weighted integral of reflected light from all depths and is difficult to determine by reflectance data alone. In this study, four Chla vertical profile classes (vertically uniform, Gaussian, exponential and hyperbolic were found to occur in three in situ vertical surveys (28 May, 19–24 July and 10–12 October in a shallow eutrophic lake, Lake Chaohu. We developed and validated a classification and regression tree (CART to determine vertical phytoplankton biomass profile classes. This was based on an algal bloom index (Normalized Difference algal Bloom Index, NDBI applied to both in situ remote sensing reflectance (Rrs and MODIS Rayleigh-corrected reflectance (Rrc data in combination with data of local wind speed. The results show the potential of retrieving Chla vertical profiles information from integrated information sources following a decision tree approach.
The world is experiencing a rapid rate of urban expansion, largely contributed by the population growth. Other factors supporting urban growth include the improved efficiency in the transportation sector and increasing dependence on cars as a means of transport. The problems attributed to the urban growth include: depletion of energy resources, water and air pollution; loss of landscapes and wildlife, loss of agricultural land, inadequate social security and lack of employment or underemployment. Aerial photography is one of the popular techniques for analyzing, planning and minimizing urbanization related problems. However, with the advances in space technology, satellite remote sensing is increasingly being utilized in the analysis and planning of the urban environment. This article outlines the strengths and limitations of potential remote sensing techniques for monitoring urban growth. The selected methods include: Principal component analysis, Maximum likelihood classification and "decision tree". The results indicate that the "classification tree" approach is the most promising for monitoring urban change, given the improved accuracy and smooth transition between the various land cover classes
Doicu, A.; Hilgers, S.; Bargen, A. von; Rozanov, A.; Eichmann, K.-U.; Savigny, C. von; Burrows, J.P.
In this study, we present the main features of the information operator approach for solving linear inverse problems arising in atmospheric remote sensing. This method is superior to the stochastic version of the Tikhonov regularization (or the optimal estimation method) due to its capability to filter out the noise-dominated components of the solution generated by an inappropriate choice of the regularization parameter. We extend this approach to iterative methods for nonlinear ill-posed problems and derive the truncated versions of the Gauss-Newton and Levenberg-Marquardt methods. Although the paper mostly focuses on discussing the mathematical details of the inverse method, retrieval results have been provided, which exemplify the performances of the methods. These results correspond to the NO 2 retrieval from SCIAMACHY limb scatter measurements and have been obtained by using the retrieval processors developed at the German Aerospace Center Oberpfaffenhofen and Institute of Environmental Physics of the University of Bremen
Pour, Amin Beiranvand; Park, Yongcheol; Park, Tae-Yoon S.; Hong, Jong Kuk; Hashim, Mazlan; Woo, Jusun; Ayoobi, Iman
Satellite remote sensing imagery is especially useful for geological investigations in Antarctica because of its remoteness and extreme environmental conditions that constrain direct geological survey. The highest percentage of exposed rocks and soils in Antarctica occurs in Northern Victoria Land (NVL). Exposed Rocks in NVL were part of the paleo-Pacific margin of East Gondwana during the Paleozoic time. This investigation provides a satellite-based remote sensing approach for regional geological mapping in the NVL, Antarctica. Landsat-8 and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) datasets were used to extract lithological-structural and mineralogical information. Several spectral-band ratio indices were developed using Landsat-8 and ASTER bands and proposed for Antarctic environments to map spectral signatures of snow/ice, iron oxide/hydroxide minerals, Al-OH-bearing and Fe, Mg-OH and CO3 mineral zones, and quartz-rich felsic and mafic-to-ultramafic lithological units. The spectral-band ratio indices were tested and implemented to Level 1 terrain-corrected (L1T) products of Landsat-8 and ASTER datasets covering the NVL. The surface distribution of the mineral assemblages was mapped using the spectral-band ratio indices and verified by geological expeditions and laboratory analysis. Resultant image maps derived from spectral-band ratio indices that developed in this study are fairly accurate and correspond well with existing geological maps of the NVL. The spectral-band ratio indices developed in this study are especially useful for geological investigations in inaccessible locations and poorly exposed lithological units in Antarctica environments.
Christensen, J.; Evenson, G. R.; Vanderhoof, M.; Wu, Q.; Golden, H. E.; Lane, C.
Surface connectivity of wetlands in the 700,000 km2 Prairie Pothole Region of North America (PPR) can occur through fill-spill and fill-merge mechanisms, with some wetlands eventually spilling into stream/river systems. These wetland-to-wetland and wetland-to-stream connections vary both spatially and temporally in PPR watersheds and are important to understanding hydrologic and biogeochemical processes in the landscape. To explore how to best characterize spatial and temporal variability in aquatic connectivity, we compared three approaches, 1) hydrological modeling alone, 2) remotely-sensed data alone, and 3) integrating remotely-sensed data into a hydrological model. These approaches were tested in the Pipestem Creek Watershed, North Dakota across a drought to deluge cycle (1990-2011). A Soil and Water Assessment Tool (SWAT) model was modified to include the water storage capacity of individual non-floodplain wetlands identified in the National Wetland Inventory (NWI) dataset. The SWAT-NWI model simulated the water balance and storage of each wetland and the temporal variability of their hydrologic connections between wetlands during the 21-year study period. However, SWAT-NWI only accounted for fill-spill, and did not allow for the expansion and merging of wetlands situated within larger depressions. Alternatively, we assessed the occurrence of fill-merge mechanisms using inundation maps derived from Landsat images on 19 cloud-free days during the 21 years. We found fill-merge mechanisms to be prevalent across the Pipestem watershed during times of deluge. The SWAT-NWI model was then modified to use LiDAR-derived depressions that account for the potential maximum depression extent, including the merging of smaller wetlands. The inundation maps were used to evaluate the ability of the SWAT-depression model to simulate fill-merge dynamics in addition to fill-spill dynamics throughout the study watershed. Ultimately, using remote sensing to inform and validate
Behling, Robert; Milewski, Robert; Chabrillat, Sabine
This paper proposes the remote sensing time series approach WLMO (Water-Land MOnitor) to monitor spatiotemporal shoreline changes. The approach uses a hierarchical classification system based on temporal MNDWI-trajectories with the goal to accommodate typical uncertainties in remote sensing shoreline extraction techniques such as existence of clouds and geometric mismatches between images. Applied to a dense Landsat time series between 1984 and 2014 for the two Namibian coastal lagoons at Walvis Bay and Sandwich Harbour the WLMO was able to identify detailed accretion and erosion progressions at the sand spits forming these lagoons. For both lagoons a northward expansion of the sand spits of up to 1000 m was identified, which corresponds well with the prevailing northwards directed ocean current and wind processes that are responsible for the material transport along the shore. At Walvis Bay we could also show that in the 30 years of analysis the sand spit's width has decreased by more than a half from 750 m in 1984-360 m in 2014. This ongoing cross-shore erosion process is a severe risk for future sand spit breaching, which would expose parts of the lagoon and the city to the open ocean. One of the major advantages of WLMO is the opportunity to analyze detailed spatiotemporal shoreline changes. Thus, it could be shown that the observed long-term accretion and erosion processes underwent great variations over time and cannot a priori be assumed as linear processes. Such detailed spatiotemporal process patterns are a prerequisite to improve the understanding of the processes forming the Namibian shorelines. Moreover, the approach has also the potential to be used in other coastal areas, because the focus on MNDWI-trajectories allows the transfer to many multispectral satellite sensors (e.g. Sentinel-2, ASTER) available worldwide.
Brown, Gareth [Sgurr Energy (Canada)
This paper presents remote sensing best practice in the wind industry. Remote sensing is a technique whereby measurements are obtained from the interaction of laser or acoustic pulses with the atmosphere. There is a vast diversity of tools and techniques available and they offer wide scope for reducing project uncertainty and risk but best practice must take into account versatility and flexibility. It should focus on the outcome in terms of results and data. However, traceability of accuracy requires comparison with conventional instruments. The framework for the Boulder protocol is given. Overviews of the guidelines for IEA SODAR and IEA LIDAR are also mentioned. The important elements of IEC 61400-12-1, an international standard for wind turbines, are given. Bankability is defined based on the Boulder protocol and a pie chart is presented that illustrates the uncertainty area covered by remote sensing. In conclusion it can be said that remote sensing is changing perceptions about how wind energy assessments can be made.
Belinda Arunarwati Margono
Remote sensing is an important data source for monitoring the change of forest cover, in terms of both total removal of forest cover (deforestation), and change of canopy cover, structure and forest ecosystem services that result in forest degradation. In the context of Intergovernmental Panel on Climate Change (IPCC), forest degradation monitoring requires information...
Rathjens, H.; Dörnhöfer, K.; Oppelt, N.
Land cover data gives the opportunity to study interactions between land cover status and environmental issues such as hydrologic processes, soil properties, or biodiversity. Land cover data often are based on classification of remote sensing data that seldom provides the requisite accuracy, spatial availability and temporal observational frequency for environmental studies. Thus, there is a high demand for accurate and spatio-temporal complete time series of land cover. In the past considerable research was undertaken to increase land cover classification accuracy, while less effort was spent on interpolation techniques. The purpose of this article is to present a space-time interpolation and revision approach for remotely sensed land cover data. The approach leverages special properties known for agricultural areas such as crop rotations or temporally static land cover classes. The newly developed IRSeL-tool (Interpolation and improvement of Remotely Sensed Land cover) corrects classification errors and interpolates missing land cover pixels. The easy-to-use tool solely requires an initial land cover data set. The IRSeL specific interpolation and revision technique, the data input requirements and data output structure are described in detail. A case study in an area around the city of Neumünster in Northern Germany from 2006 to 2012 was performed for IRSeL validation with initial land cover data sets (Landsat TM image classifications) for the years 2006, 2007, 2009, 2010 and 2011. The results of the case study showed that IRSeL performs well; including years with no classification data overall accuracy values for IRSeL interpolated pixels range from 0.63 to 0.81. IRSeL application significantly increases the accuracy of the land cover data; overall accuracy values rise 0.08 in average resulting in overall accuracy values of at least 0.86. Considering estimated reliabilities, the IRSeL tool provides a temporally and spatially completed and revised land cover
Wright, Daniel; Yatheendradas, Soni; Peters-Lidard, Christa; Kirschbaum, Dalia; Ayalew, Tibebu; Mantilla, Ricardo; Krajewski, Witold
Progress on the assessment of rainfall-driven hazards such as floods and landslides has been hampered by the challenge of characterizing the frequency, intensity, and structure of extreme rainfall at the watershed or hillslope scale. Conventional approaches rely on simplifying assumptions and are strongly dependent on the location, the availability of long-term rain gage measurements, and the subjectivity of the analyst. Regional and global-scale rainfall remote sensing products provide an alternative, but are limited by relatively short (~15-year) observational records. To overcome this, we have coupled these remote sensing products with a space-time resampling framework known as stochastic storm transposition (SST). SST "lengthens" the rainfall record by resampling from a catalog of observed storms from a user-defined region, effectively recreating the regional extreme rainfall hydroclimate. This coupling has been codified in Rainy Day, a Python-based platform for quickly generating large numbers of probabilistic extreme rainfall "scenarios" at any point on the globe. Rainy Day is readily compatible with any gridded rainfall dataset. The user can optionally incorporate regional rain gage or weather radar measurements for bias correction using the Precipitation Uncertainties for Satellite Hydrology (PUSH) framework. Results from Rainy Day using the CMORPH satellite precipitation product are compared with local observations in two examples. The first example is peak discharge estimation in a medium-sized (~4000 square km) watershed in the central United States performed using CUENCAS, a parsimonious physically-based distributed hydrologic model. The second example is rainfall frequency analysis for Saint Lucia, a small volcanic island in the eastern Caribbean that is prone to landslides and flash floods. The distinct rainfall hydroclimates of the two example sites illustrate the flexibility of the approach and its usefulness for hazard analysis in data-poor regions.
The application of remote sensing to the study of lakes is begun in years 80 with the lunch of the satellites of second generation. Many experiences have indicated the contribution of remote sensing for the limnology [it
Lippitt, Christopher; Coulter, Lloyd
This book documents the state of the art in the use of remote sensing to address time-sensitive information requirements. Specifically, it brings together a group of authors who are both researchers and practitioners, who work toward or are currently using remote sensing to address time-sensitive information requirements with the goal of advancing the effective use of remote sensing to supply time-sensitive information. The book addresses the theoretical implications of time-sensitivity on the remote sensing process, assessments or descriptions of methods for expediting the delivery and improving the quality of information derived from remote sensing, and describes and analyzes time-sensitive remote sensing applications, with an emphasis on lessons learned. This book is intended for remote sensing scientists, practitioners (e.g., emergency responders or administrators of emergency response agencies), and students, but will also be of use to those seeking to understand the potential of remote sensing to addres...
Full Text Available Remote sensing (RS of plant canopies permits non-intrusive, high-throughput monitoring of plant physiological characteristics. This study compared three RS approaches using a low flying UAV (unmanned aerial vehicle, with that of proximal sensing, and satellite-based imagery. Two physiological traits were considered, canopy temperature (CT and a vegetation index (NDVI, to determine the most viable approaches for large scale crop genetic improvement. The UAV-based platform achieves plot-level resolution while measuring several hundred plots in one mission via high-resolution thermal and multispectral imagery measured at altitudes of 30-100 m. The satellite measures multispectral imagery from an altitude of 770 km. Information was compared with proximal measurements using IR thermometers and an NDVI sensor at a distance of 0.5-1m above plots. For robust comparisons, CT and NDVI were assessed on panels of elite cultivars under irrigated and drought conditions, in different thermal regimes, and on un-adapted genetic resources under water deficit. Correlations between airborne data and yield/biomass at maturity were generally higher than equivalent proximal correlations. NDVI was derived from high-resolution satellite imagery for only larger sized plots (8.5 x 2.4 m due to restricted pixel density. Results support use of UAV-based RS techniques for high-throughput phenotyping for both precision and efficiency.
Pyke, Benjamin J. [Univ. of Arizona, Tucson, AZ (United States)
The purpose of this project, Laser Active Transmitter & Receiver (LATR), was to build a mobile ground based remote sensing system that can detect, identify and quantify a specific gaseous species using Differential Absorption LIDAR (DIAL). This thesis project is concerned with the development and field testing of a mid-wave infrared active remote sensing system, capable of identifying and quantifying emissions in the 3.2 – 3.5 micron range. The goal is to give a brief description of what remote sensing is about and the specific technique used to analyze the collected data. The thesis will discuss the transmitter and the associated subsystems used to create the required wavelength, and the receiver used to collect the returns. And finally, the thesis will discuss the process of collecting the data and some of the results from field and lab collections.
Singh, R. K.; Budde, M. E.; Senay, G. B.; Rowland, J.
Forecasting crop production in advance of crop harvest plays a significant role in drought impact management, improved food security, stabilizing food grain market prices, and poverty reduction. This becomes essential, particularly in Sub-Saharan Africa, where agriculture is a critical source of livelihoods, but lacks good quality agricultural statistical data. With increasing availability of low cost satellite data, faster computing power, and development of modeling algorithms, remotely sensed images are becoming a common source for deriving information for agricultural, drought, and water management. Many researchers have shown that the Normalized Difference Vegetation Index (NDVI), based on red and near-infrared reflectance, can be effectively used for estimating crop production and yield. Similarly, crop production and yield have been closely related to evapotranspiration (ET) also as there are strong linkages between production/yield and transpiration based on plant physiology. Thus, we combined NDVI and ET information from remotely sensed images for estimating total production and crop yield prior to crop harvest for Niger and Burkina Faso in West Africa. We identified the optimum time (dekads 23-29) for cumulating NDVI and ET and developed a new algorithm for estimating crop production and yield. We used the crop data from 2003 to 2008 to calibrate our model and the data from 2009 to 2013 for validation. Our results showed that total crop production can be estimated within 5% of actual production (R2 = 0.98) about 30-45 days before end of the harvest season. This novel approach can be operationalized to provide a valuable tool to decision makers for better drought impact management in drought-prone regions of the world.
Trifonov, Yu V
Description of data devices for deriving multi-spectral measuring television measurement data of middle and high resolution through use of second generation Meteor-type satellites. Options for developing a permanent and active remote sensing system in USSR are discussed. It is noted that the present experiment is an important step in that direction. Design and structural data for this particular device and its application in the experiment are covered.
Hantson, W.; Kooistra, L.; Slim, P.A.
In this study we mapped (alien) invasive shrubs for management and conservation purposes. On the study site, the Wadden Sea Island of Vlieland, they are a serious treat for the quality of the grey dune habitat. We developed a remote sensing approach that delivers detailed and standardized maps of
Brooks, J. R.; Mushet, David M.; Vanderhoof, Melanie; Leibowitz, Scott G.; Neff, Brian; Christensen, J. R.; Rosenberry, Donald O.; Rugh, W. D.; Alexander, L.C.
Understanding hydrologic connectivity between wetlands and perennial streams is critical to understanding the reliance of stream flow on inputs from wetlands. We used the isotopic evaporation signal in water and remote sensing to examine wetland‐stream hydrologic connectivity within the Pipestem Creek watershed, North Dakota, a watershed dominated by prairie‐pothole wetlands. Pipestem Creek exhibited an evaporated‐water signal that had approximately half the isotopic‐enrichment signal found in most evaporatively enriched prairie‐pothole wetlands. Groundwater adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporative enrichment, indicating that enriched surface water did not contribute significantly to groundwater discharging into Pipestem Creek. The estimated surface water area necessary to generate the evaporation signal within Pipestem Creek was highly dynamic, varied primarily with the amount of discharge, and was typically greater than the immediate Pipestem Creek surface water area, indicating that surficial flow from wetlands contributed to stream flow throughout the summer. We propose a dynamic range of spilling thresholds for prairie‐pothole wetlands across the watershed allowing for wetland inputs even during low‐flow periods. Combining Landsat estimates with the isotopic approach allowed determination of potential (Landsat) and actual (isotope) contributing areas in wetland‐dominated systems. This combined approach can give insights into the changes in location and magnitude of surface water and groundwater pathways over time. This approach can be used in other areas where evaporation from wetlands results in a sufficient evaporative isotopic signal.
Rozanov, Vladimir V.; Rozanov, Alexei V.
The paper is devoted to the investigation of the relationship between different methods used to derive weighting functions required to solve numerous inverse problems related to the remote sensing of the Earth's atmosphere by means of scattered solar light observations. The first method commonly referred to as the forward-adjoint approach is based on a joint solution of the forward and adjoint radiative transfer equations and the second one requires the linearized forward radiative transfer equation to be solved. In the framework of the forward-adjoint method we consider two approaches commonly used to derive the weighting functions. These approaches are referenced as the 'response function' and the 'formal solution' techniques, respectively. We demonstrate here that the weighting functions derived employing the formal solution technique can also be obtained substituting the analytical representations for the direct forward and direct adjoint intensities into corresponding expressions obtained in the framework of the response function technique. The advantages and disadvantages of different techniques are discussed
Giorgoudis, Marios D.; Hadjimitsis, Diofantos G.; Shiftan, Yoram
The main advantage of using GIS is its ability to access and analyze spatially distributed data. The applications of GIS to transportation can be viewed as involving either on data retrieval; data integrator; or data analysis. The use of remote sensing can assist the retrieval of land use changes. Indeed, the integration of GIS and remote sensing will be used to fill the gap in the smart transport planning. A four step research is going to be done in order to try to integrate the usage of GIS and remote sensing to sustainable transport planning. The proposed research will be held in the city of Limassol, Cyprus. The data that are going to be used are data that are going to be collected through questionnaires, and other available data from the Cyprus Public Works Department and from the Remote Sensing Laboratory and Geo-Environment Research Lab of the Cyprus University of Technology. Overall, statistical analysis and market segmentation of data will be done, the land usage will be examined, and a scenario building on mode choice will be held. This paper presents an overview of the methodology that will be adopted.
Tropical rainforest areas are difficult to classify in the digital analysis of remote sensing data because of spatial heterogeneity. Often many technical solutions are adopted to reduce the ‘problem’ of spatial heterogeneity. This thesis describes theory and methods that now use this
Francioni, Mirko; Coggan, John; Eyre, Matthew; Stead, Doug
Understanding the key factors controlling slope failure mechanisms in coastal areas is the first and most important step for analyzing, reconstructing and predicting the scale, location and extent of future instability in rocky coastlines. Different failure mechanisms may be possible depending on the influence of the engineering properties of the rock mass (including the fracture network), the persistence and type of discontinuity and the relative aspect or orientation of the coastline. Using a section of the North Coast of Cornwall, UK, as an example we present a multi-disciplinary approach for characterizing landslide risk associated with coastal instabilities in a blocky rock mass. Remotely captured terrestrial and aerial LiDAR and photogrammetric data were interrogated using Geographic Information System (GIS) techniques to provide a framework for subsequent analysis, interpretation and validation. The remote sensing mapping data was used to define the rock mass discontinuity network of the area and to differentiate between major and minor geological structures controlling the evolution of the North Coast of Cornwall. Kinematic instability maps generated from aerial LiDAR data using GIS techniques and results from structural and engineering geological surveys are presented. With this method, it was possible to highlight the types of kinematic failure mechanism that may generate coastal landslides and highlight areas that are more susceptible to instability or increased risk of future instability. Multi-temporal aerial LiDAR data and orthophotos were also studied using GIS techniques to locate recent landslide failures, validate the results obtained from the kinematic instability maps through site observations and provide improved understanding of the factors controlling the coastal geomorphology. The approach adopted is not only useful for academic research, but also for local authorities and consultancy's when assessing the likely risks of coastal instability.
Full Text Available Collecting vast amount of data does not solely help to fulfil information needs related to crowd monitoring, it is rather important to collect data that is suitable to meet specific information requirements. In order to address this issue, a prototype is developed to facilitate the combination of UAV-based RGB and thermal remote sensing datasets. In an experimental approach, image sensors were mounted on a remotely piloted aircraft and captured two video datasets over a crowd. A group of volunteers performed diverse movements that depict real world scenarios. The prototype is deriving the movement on the ground and is programmed in MATLAB. This novel detection approach using combined data is afterwards evaluated against detection algorithms that only use a single data source. Our tests show that the combination of RGB and thermal remote sensing data is beneficial for the field of crowd monitoring regarding the detection of crowd movement.
Albajes-Eizagirre, Anton; Romero, Laia; Soria-Frisch, Aureli; Vanhellemont, Quinten
Impact of jellyfish in human activities has been increasingly reported worldwide in recent years. Segments such as tourism, water sports and leisure, fisheries and aquaculture are commonly damaged when facing blooms of gelatinous zooplankton. Hence the prediction of the appearance and disappearance of jellyfish in our coasts, which is not fully understood from its biological point of view, has been approached as a pattern recognition problem in the paper presented herein, where a set of potential ecological cues was selected to test their usefulness for prediction. Remote sensing data was used to describe environmental conditions that could support the occurrence of jellyfish blooms with the aim of capturing physical-biological interactions: forcing, coastal morphology, food availability, and water mass characteristics are some of the variables that seem to exert an effect on jellyfish accumulation on the shoreline, under specific spatial and temporal windows. A data-driven model based on computational intelligence techniques has been designed and implemented to predict jellyfish events on the beach area as a function of environmental conditions. Data from 2009 over the NW Mediterranean continental shelf have been used to train and test this prediction protocol. Standard level 2 products are used from MODIS (NASA OceanColor) and MERIS (ESA - FRS data). The procedure for designing the analysis system can be described as following. The aforementioned satellite data has been used as feature set for the performance evaluation. Ground truth has been extracted from visual observations by human agents on different beach sites along the Catalan area. After collecting the evaluation data set, the performance between different computational intelligence approaches have been compared. The outperforming one in terms of its generalization capability has been selected for prediction recall. Different tests have been conducted in order to assess the prediction capability of the
Brosius, Craig A.; And Others
This document is designed to help senior high school students study remote sensing technology and techniques in relation to the environmental sciences. It discusses the acquisition, analysis, and use of ecological remote data. Material is divided into three sections and an appendix. Section One is an overview of the basics of remote sensing.…
Smith, James A.; Blattner, Tim; Messmer, Peter
The broad-scale reductions and shifts that may be expected under climate change in the availability and quality of stopover habitat for long-distance migrants is an area of increasing concern for conservation biologists. Researchers generally have taken two broad approaches to the modeling of migration behaviour to understand the impact of these changes on migratory bird populations. These include models based on causal processes and their response to environmental stimulation, "mechanistic models", or models that primarily are based on observed animal distribution patterns and the correlation of these patterns with environmental variables, i.e. "data driven" models. Investigators have applied the latter technique to forecast changes in migration patterns with changes in the environment, for example, as might be expected under climate change, by forecasting how the underlying environmental data layers upon which the relationships are built will change over time. The learned geostatstical correlations are then applied to the modified data layers.. However, this is problematic. Even if the projections of how the underlying data layers will change are correct, it is not evident that the statistical relationships will remain the same, i.e. that the animal organism may not adapt its' behaviour to the changing conditions. Mechanistic models that explicitly take into account the physical, biological, and behaviour responses of an organism as well as the underlying changes in the landscape offer an alternative to address these shortcomings. The availability of satellite remote sensing observations at multiple spatial and temporal scales, coupled with advances in climate modeling and information technologies enable the application of the mechanistic models to predict how continental bird migration patterns may change in response to environmental change. In earlier work, we simulated the impact of effects of wetland loss and inter-annual variability on the fitness of
Full Text Available Land cover data represent a fundamental data source for various types of scientific research. The classification of land cover based on satellite data is a challenging task, and an efficient classification method is needed. In this study, an automatic scheme is proposed for the classification of land use using multispectral remote sensing images based on change detection and a semi-supervised classifier. The satellite image can be automatically classified using only the prior land cover map and existing images; therefore human involvement is reduced to a minimum, ensuring the operability of the method. The method was tested in the Qingpu District of Shanghai, China. Using Environment Satellite 1(HJ-1 images of 2009 with 30 m spatial resolution, the areas were classified into five main types of land cover based on previous land cover data and spectral features. The results agreed on validation of land cover maps well with a Kappa value of 0.79 and statistical area biases in proportion less than 6%. This study proposed a simple semi-automatic approach for land cover classification by using prior maps with satisfied accuracy, which integrated the accuracy of visual interpretation and performance of automatic classification methods. The method can be used for land cover mapping in areas lacking ground reference information or identifying rapid variation of land cover regions (such as rapid urbanization with convenience.
Full Text Available This paper provides evidence on the usefulness of very high spatial resolution (VHR imagery in gathering socioeconomic information in urban settlements. We use land cover, spectral, structure and texture features extracted from a Google Earth image of Liverpool (UK to evaluate their potential to predict Living Environment Deprivation at a small statistical area level. We also contribute to the methodological literature on the estimation of socioeconomic indices with remote-sensing data by introducing elements from modern machine learning. In addition to classical approaches such as Ordinary Least Squares (OLS regression and a spatial lag model, we explore the potential of the Gradient Boost Regressor and Random Forests to improve predictive performance and accuracy. In addition to novel predicting methods, we also introduce tools for model interpretation and evaluation such as feature importance and partial dependence plots, or cross-validation. Our results show that Random Forest proved to be the best model with an R2 of around 0.54, followed by Gradient Boost Regressor with 0.5. Both the spatial lag model and the OLS fall behind with significantly lower performances of 0.43 and 0.3, respectively.
The loss of mangrove forests to aquaculture, particularly shrimp farming, in coastal Thailand presents serious environmental and societal problems. Shrimp farming is one of the fastest growing aquaculture sectors in many parts of the world, as well as one of the most controversial. In spite of considerable work put into understanding the impacts of shrimp aquaculture, few studies provide detailed assessment of the issue through time. This research compares three change detection techniques (Object-based; Change Vector Analysis (CVA); and Integrated GIS and Remote Sensing) in order to assess the mangrove conversion caused by aquaculture development in Krabi Province, Thailand between 1989, 2001 and 2007 using Landsat TM data. All three methods provide valuable information though each has its own merits. Preliminary results show 40% loss of mangroves between 1989 and 2007, 25% of which is to aquaculture development, 10% to urban, and 5% to agricultural land. This study will help establish a methodology that will aid coastal communities in Southeast Asia in determining sustainable land use management approaches.
Ustinov, Eugene A
This book contains a detailed presentation of general principles of sensitivity analysis as well as their applications to sample cases of remote sensing experiments. An emphasis is made on applications of adjoint problems, because they are more efficient in many practical cases, although their formulation may seem counterintuitive to a beginner. Special attention is paid to forward problems based on higher-order partial differential equations, where a novel matrix operator approach to formulation of corresponding adjoint problems is presented. Sensitivity analysis (SA) serves for quantitative models of physical objects the same purpose, as differential calculus does for functions. SA provides derivatives of model output parameters (observables) with respect to input parameters. In remote sensing SA provides computer-efficient means to compute the jacobians, matrices of partial derivatives of observables with respect to the geophysical parameters of interest. The jacobians are used to solve corresponding inver...
Peña, Alfredo; Hasager, Charlotte Bay; Lange, Julia
The Remote Sensing in Wind Energy report provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind it began in year 2008 at DTU Wind Energy (formerly Risø) during the first PhD Summer School: Remote Sensing in Wind Energy...... state-of-the-art ‘guideline’ available for people involved in Remote Sensing in Wind Energy....
The Remote Sensing in Wind Energy Compendium provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind this compendium began in year 2008 at Risø DTU during the first PhD Summer School: Remote Sensing in Wind Energy. Thus......-of-the-art compendium available for people involved in Remote Sensing in Wind Energy....
Program Manager AFOSR/RSE Air Force Research Laboratory Remote Sensing and Imaging Physics 7 March 2012 Report Documentation Page Form...00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Remote Sensing And Imaging Physics 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Imaging of Space Objects •Information without Imaging •Predicting the Location of Space Objects • Remote Sensing in Extreme Conditions •Propagation
Bishop, Charlotte; Rivard, Benoit; de Souza Filho, Carlos; van der Meer, Freek
Geology is defined as the 'study of the planet Earth - the materials of which it is made, the processes that act on these materials, the products formed, and the history of the planet and its life forms since its origin' (Bates and Jackson, 1976). Remote sensing has seen a number of variable definitions such as those by Sabins and Lillesand and Kiefer in their respective textbooks (Sabins, 1996; Lillesand and Kiefer, 2000). Floyd Sabins (Sabins, 1996) defined it as 'the science of acquiring, processing and interpreting images that record the interaction between electromagnetic energy and matter' while Lillesand and Kiefer (Lillesand and Kiefer, 2000) defined it as 'the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation'. Thus Geological Remote Sensing can be considered the study of, not just Earth given the breadth of work undertaken in planetary science, geological features and surfaces and their interaction with the electromagnetic spectrum using technology that is not in direct contact with the features of interest.
Full Text Available In recent decades, land cover change detection (LCCD using very high-spatial resolution (VHR remote sensing images has been a major research topic. However, VHR remote sensing images usually lead to a large amount of noises in spectra, thereby reducing the reliability of the detected results. To solve this problem, this study proposes an object-based expectation maximization (OBEM post-processing approach for enhancing raw LCCD results. OBEM defines a refinement of the labeling in a detected map to enhance its raw detection accuracies. Current mainstream change detection (preprocessing techniques concentrate on proposing a change magnitude measurement or considering image spatial features to obtain a change detection map. The proposed OBEM approach is a new solution to enhance change detection accuracy by refining the raw result. Post-processing approaches can achieve competitive accuracies to the preprocessing methods, but in a direct and succinct manner. The proposed OBEM post-processing method synthetically considers multi-scale segmentation and expectation maximum algorithms to refine the raw change detection result. Then, the influence of the scale of segmentation on the LCCD accuracy of the proposed OBEM is investigated. Four pairs of remote sensing images, one of two pairs (aerial image with 0.5 m/pixel resolution which depict two landslide sites on Landtau Island, Hong Kong, China, are used in the experiments to evaluate the effectiveness of the proposed approach. In addition, the proposed approach is applied, and validated by two case studies, LCCD in Tianjin City China (SPOT-5 satellite image with 2.5 m/pixel resolution and Mexico forest fire case (Landsat TM images with 30 m/pixel resolution, respectively. Quantitative evaluations show that the proposed OBEM post-processing approach can achieve better performance and higher accuracies than several commonly used preprocessing methods. To the best of the authors’ knowledge, this type
selected, practice-oriented approaches are evaluated too, finally widely-used dimension metrics like Root Mean Squared Error (RMSE or confusion matrix are discussed. The authors present data quality features of well-defined and poorly defined object. The central part of the study is the land cover mapping, describing its accuracy management model, presented relevance and uncertainty measures of its influencing quality dimensions. In the paper theory is supported by a case study, where the remote sensing technology is used for supporting the area-based agricultural subsidies of the European Union, in Hungarian administration.
Barsi, Á.; Kugler, Zs.; László, I.; Szabó, Gy.; Abdulmutalib, H. M.
-oriented approaches are evaluated too, finally widely-used dimension metrics like Root Mean Squared Error (RMSE) or confusion matrix are discussed. The authors present data quality features of well-defined and poorly defined object. The central part of the study is the land cover mapping, describing its accuracy management model, presented relevance and uncertainty measures of its influencing quality dimensions. In the paper theory is supported by a case study, where the remote sensing technology is used for supporting the area-based agricultural subsidies of the European Union, in Hungarian administration.
Dons, Klaus; Grogan, Kenneth
due to steep terrain, • phenological gradients across natural, agricultural and forestry ecosystems including plantations and • the need to serve the REDD-specific context of deforestation and forest degradation across spatial and temporal scales make remote sensing based approaches particularly...... be expected from remote sensing imagery and the provided information shall help to better anticipate problems that will be encountered when acquiring, analyzing and interpreting remote sensing data. Beyond remote sensing, it may be a good point of departure for a large group of scientists with a diverse...... and governance, and deforestation and forest degradation processes. The second part summarizes the available literature on remote sensing based good practices for REDD. It largely draws from the documents of the Intergovernmental Panel on Climate Change (IPCC), the United Nations Framework Convention on Climate...
Podest, E.; McDonald, K. C.; Schroeder, R.; Pinto, N.; Zimmerman, R.; Horna, V.
Wetland ecosystems are prevalent in the Amazon basin, especially in northern Peru. Of specific interest are palm swamp wetlands because they are characterized by constant surface inundation and moderate seasonal water level variation. This combination of constantly saturated soils and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, it is critical to develop methods to quantify their spatial extent and inundation state in order to assess their carbon dynamics. Spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We developed a remote sensing methodology using multi-sensor remote sensing data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR), Shuttle Radar Topography Mission (SRTM) DEM, and Landsat to derive maps at 100 meter resolution of palm swamp extent and inundation based on ground data collections; and combined active and passive microwave data from AMSR-E and QuikSCAT to derive inundation extent at 25 kilometer resolution on a weekly basis. We then compared information content and accuracy of the coarse resolution products relative to the high-resolution datasets. The synergistic combination of high and low resolution datasets allowed for characterization of palm swamps and assessment of their flooding status. This work has been undertaken partly within the framework of the JAXA ALOS Kyoto & Carbon Initiative. PALSAR data have been provided by JAXA. Portions of this work were carried out at the Jet Propulsion Laboratory
Elkadiri, R.; Sultan, M.; Elbayoumi, T.; Chouinard, K.
We developed and applied an integrated approach to construct predictive tools with lead times of 1 to 12 months to forecast precipitation amounts over the Middle East and North Africa (MENA) region. The following steps were conducted: (1) acquire and analyze temporal remote sensing-based precipitation datasets (i.e. Tropical Rainfall Measuring Mission [TRMM]) over five main water source regions in the MENA area (i.e. Atlas Mountains in Morocco, Southern Sudan, Red Sea Hills of Yemen, and Blue Nile and White Nile source areas) throughout the investigation period (1998 to 2015), (2) acquire and extract monthly values for all of the climatic indices that are likely to influence the climatic patterns over the MENA region (e.g., Northern Atlantic Oscillation [NOI], Southern Oscillation Index [SOI], and Tropical North Atlantic Index [TNA]); and (3) apply data mining methods to extract relationships between the observed precipitation and the controlling factors (climatic indices) and use predictive tools to forecast monthly precipitation over each of the identified pilot study areas. Preliminary results indicate that by using the period from January 1998 until August 2012 for model training and the period from September 2012 to January 2015 for testing, precipitation can be successfully predicted with a three-months lead over South West Yemen, Atlas Mountains in Morocco, Southern Sudan, Blue Nile sources and White Nile sources with confidence (Pearson correlation coefficient: 0.911, 0.823, 0.807, 0.801 and 0.895 respectively). Future work will focus on applying this technique for prediction of precipitation over each of the climatically contiguous areas of the MENA region. If our efforts are successful, our findings will lead the way to the development and implementation of sound water management scenarios for the MENA countries.
Narasimha Rao, Gudikandhula; Jagadeeswara Rao, Peddada; Duvvuru, Rajesh
Wild fires have significant impact on atmosphere and lives. The demand of predicting exact fire area in forest may help fire management team by using drone as a robot. These are flexible, inexpensive and elevated-motion remote sensing systems that use drones as platforms are important for substantial data gaps and supplementing the capabilities of manned aircraft and satellite remote sensing systems. In addition, powerful computational tools are essential for predicting certain burned area in the duration of a forest fire. The reason of this study is to built up a smart system based on semantic neural networking for the forecast of burned areas. The usage of virtual reality simulator is used to support the instruction process of fire fighters and all users for saving of surrounded wild lives by using a naive method Semantic Neural Network System (SNNS). Semantics are valuable initially to have a enhanced representation of the burned area prediction and better alteration of simulation situation to the users. In meticulous, consequences obtained with geometric semantic neural networking is extensively superior to other methods. This learning suggests that deeper investigation of neural networking in the field of forest fires prediction could be productive.
Marshall, M.; Tu, K.; Funk, C.; Michaelsen, J.; Williams, P.; Williams, C.; Ardö, J.; Boucher, M.; Cappelaere, B.; de Grandcourt, A.; Nickless, A.; Nouvellon, Y.; Scholes, R.; Kutsch, W.
Climate change is expected to have the greatest impact on the world's economically poor. In the Sahel, a climatically sensitive region where rain-fed agriculture is the primary livelihood, expected decreases in water supply will increase food insecurity. Studies on climate change and the intensification of the water cycle in sub-Saharan Africa are few. This is due in part to poor calibration of modeled evapotranspiration (ET), a key input in continental-scale hydrologic models. In this study, a remote sensing model of transpiration (the primary component of ET), driven by a time series of vegetation indices, was used to substitute transpiration from the Global Land Data Assimilation System realization of the National Centers for Environmental Prediction, Oregon State University, Air Force, and Hydrology Research Laboratory at National Weather Service Land Surface Model (GNOAH) to improve total ET model estimates for monitoring purposes in sub-Saharan Africa. The performance of the hybrid model was compared against GNOAH ET and the remote sensing method using eight eddy flux towers representing major biomes of sub-Saharan Africa. The greatest improvements in model performance were at humid sites with dense vegetation, while performance at semi-arid sites was poor, but better than the models before hybridization. The reduction in errors using the hybrid model can be attributed to the integration of a simple canopy scheme that depends primarily on low bias surface climate reanalysis data and is driven primarily by a time series of vegetation indices.
Zhou, G.; Huang, W.; Zhou, X.; He, C.; Li, X.; Huang, Y.; Zhang, L.
In remote sensing applications, the accuracy of time interval measurement is one of the most important parameters that affect the quality of pulsed lidar data. The traditional time interval measurement technique has the disadvantages of low measurement accuracy, complicated circuit structure and large error. A high-precision time interval data cannot be obtained in these traditional methods. In order to obtain higher quality of remote sensing cloud images based on the time interval measurement, a higher accuracy time interval measurement method is proposed. The method is based on charging the capacitance and sampling the change of capacitor voltage at the same time. Firstly, the approximate model of the capacitance voltage curve in the time of flight of pulse is fitted based on the sampled data. Then, the whole charging time is obtained with the fitting function. In this method, only a high-speed A/D sampler and capacitor are required in a single receiving channel, and the collected data is processed directly in the main control unit. The experimental results show that the proposed method can get error less than 3 ps. Compared with other methods, the proposed method improves the time interval accuracy by at least 20 %.
Full Text Available In view of the fact that oil spill remote sensing could only generate the oil slick information at a specific time and that traditional oil spill simulation models were not designed to deal with dynamic conditions, a dynamic data-driven application system (DDDAS was introduced. The DDDAS entails both the ability to incorporate additional data into an executing application and, in reverse, the ability of applications to dynamically steer the measurement process. Based on the DDDAS, combing a remote sensor system that detects oil spills with a numerical simulation, an integrated data processing, analysis, forecasting and emergency response system was established. Once an oil spill accident occurs, the DDDAS-based oil spill model receives information about the oil slick extracted from the dynamic remote sensor data in the simulation. Through comparison, information fusion and feedback updates, continuous and more precise oil spill simulation results can be obtained. Then, the simulation results can provide help for disaster control and clean-up. The Penglai, Xingang and Suizhong oil spill results showed our simulation model could increase the prediction accuracy and reduce the error caused by empirical parameters in existing simulation systems. Therefore, the DDDAS-based detection and simulation system can effectively improve oil spill simulation and diffusion forecasting, as well as provide decision-making information and technical support for emergency responses to oil spills.
Cox, Cary M.
This dissertation advances geoinformation science at the intersection of hyperspectral remote sensing and edge detection methods. A relatively new phenomenology among its remote sensing peers, hyperspectral imagery (HSI) comprises only about 7% of all remote sensing research - there are five times as many radar-focused peer reviewed journal articles than hyperspectral-focused peer reviewed journal articles. Similarly, edge detection studies comprise only about 8% of image processing research, most of which is dedicated to image processing techniques most closely associated with end results, such as image classification and feature extraction. Given the centrality of edge detection to mapping, that most important of geographic functions, improving the collective understanding of hyperspectral imagery edge detection methods constitutes a research objective aligned to the heart of geoinformation sciences. Consequently, this dissertation endeavors to narrow the HSI edge detection research gap by advancing three HSI edge detection methods designed to leverage HSI's unique chemical identification capabilities in pursuit of generating accurate, high-quality edge planes. The Di Zenzo-based gradient edge detection algorithm, an innovative version of the Resmini HySPADE edge detection algorithm and a level set-based edge detection algorithm are tested against 15 traditional and non-traditional HSI datasets spanning a range of HSI data configurations, spectral resolutions, spatial resolutions, bandpasses and applications. This study empirically measures algorithm performance against Dr. John Canny's six criteria for a good edge operator: false positives, false negatives, localization, single-point response, robustness to noise and unbroken edges. The end state is a suite of spatial-spectral edge detection algorithms that produce satisfactory edge results against a range of hyperspectral data types applicable to a diverse set of earth remote sensing applications. This work
Peña, Alfredo; Hasager, Charlotte Bay; Badger, Merete
The Remote Sensing in Wind Energy report provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind it began in year 2008 at DTU Wind Energy (formerly Risø) during the first PhD Summer School: Remote Sensing in Wind Energy...... colleagues in the Meteorology and Test and Measurements Sections from DTU Wind Energy in the PhD Summer Schools. We hope to continue adding more topics in future editions and to update and improve as necessary, to provide a truly state-of-the-art ‘guideline’ available for people involved in Remote Sensing...
Honea, R.B.; Shumpert, B.L.; Edwards, R.G.; Margle, S.M.; Coleman, P.R.; Smyre, J.L.; Rush, R.M.; Durfee, R.C.
This paper documents the results of an assessment of a variety of techniques for estimating residential population for a five-mile radial grid around a nuclear power plant. The study area surrounded the proposed Limerick Nuclear Power Plant located near Philadelphia, PA. Techniques evaluated ranged from the use of air photos to infer population from housing distributions to the use of Landsat data to characterize probable residential population around the plant site. Although the techniques involving the use of Landsat data provided good results, a simple proportional area allocation method and the current procedure used by Oak Ridge National Laboratory for the Nuclear Regulatory Commission were among the best techniques. Further research using other sites and better resolution satellite data is recommended to investigate the possible refinement of population estimates using remote sensing media. 34 references, 10 figures, 2 tables
Jain, S C; Miller, J R
A method, using an optimization scheme, has been developed for the interpretation of spectral albedo (or spectral reflectance) curves obtained from remotely sensed water color data. This method used a two-flow model of the radiation flow and solves for the albedo. Optimization fitting of predicted to observed reflectance data is performed by a quadratic interpolation method for the variables chlorophyll concentration and scattering coefficient. The technique is applied to airborne water color data obtained from Kawartha Lakes, Sargasso Sea, and Nova Scotia coast. The modeled spectral albedo curves are compared to those obtained experimentally, and the computed optimum water parameters are compared to ground truth values. It is shown that the backscattered spectral signal contains information that can be interpreted to give quantitative estimates of the chlorophyll concentration and turbidity in the waters studied.
Rogge, Derek; Bachmann, Martin; Rivard, Benoit
Spectral decorrelation (transformations) methods have long been used in remote sensing. Transformation of the image data onto eigenvectors that comprise physically meaningful spectral properties (signal) can be used to reduce the dimensionality of hyperspectral images as the number of spectrally...... distinct signal sources composing a given hyperspectral scene is generally much less than the number of spectral bands. Determining eigenvectors dominated by signal variance as opposed to noise is a difficult task. Problems also arise in using these transformations on large images, multiple flight...... and spectral subsampling to the data, which is accomplished by deriving a limited set of eigenvectors for spatially contiguous subsets. These subset eigenvectors are compiled together to form a new noise reduced data set, which is subsequently used to derive a set of global orthogonal eigenvectors. Data from...
Calvario, Gabriela; Sierra, Basilio; Alarcón, Teresa E; Hernandez, Carmen; Dalmau, Oscar
The use of Unmanned Aerial Vehicles (UAVs) based on remote sensing has generated low cost monitoring, since the data can be acquired quickly and easily. This paper reports the experience related to agave crop analysis with a low cost UAV. The data were processed by traditional photogrammetric flow and data extraction techniques were applied to extract new layers and separate the agave plants from weeds and other elements of the environment. Our proposal combines elements of photogrammetry, computer vision, data mining, geomatics and computer science. This fusion leads to very interesting results in agave control. This paper aims to demonstrate the potential of UAV monitoring in agave crops and the importance of information processing with reliable data flow.
Lees, K.; Khomik, M.; Clark, J. M.; Quaife, T. L.; Artz, R.
Peatlands are an important part of the Earth's carbon cycle, comprising approximately a third of the global terrestrial carbon store. However, peatlands are sensitive to climatic change and human mismanagement, and many are now degraded and acting as carbon sources. Restoration work is being undertaken at many sites around the world, but monitoring the success of these schemes can be difficult and costly using traditional methods. A landscape-scale alternative is to use satellite data in order to assess the condition of peatlands and estimate carbon fluxes. This work focuses on study sites in Northern Scotland, where parts of the largest blanket bog in Europe are being restored from forest plantations. A combination of laboratory and fieldwork has been used to assess the Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP) and respiration of peatland sites in different conditions, and the climatic vulnerability of key peat-forming Sphagnum species. The results from these studies have been compared with spectral data in order to evaluate the extent to which remote sensing can function as a source of information for peatland health and carbon flux models. This work considers particularly the effects of scale in calculating peatland carbon flux. Flux data includes chamber and eddy covariance measurements of carbon dioxide, and radiometric observations include both handheld spectroradiometer results and satellite images. Results suggest that despite the small-scale heterogeneity and unique ecosystem factors in blanket bogs, remote sensing can be a useful tool in monitoring peatland health and carbon sequestration. In particular, this study gives unique insights into the relationships between peatland vegetation, carbon flux and spectral reflectance.
Atwell, B. H.
The Mississippi Sound Remote Sensing Study was initiated as part of the research program of the NASA Earth Resources Laboratory. The objective of this study is development of remote sensing techniques to study near-shore marine waters. Included within this general objective are the following: (1) evaluate existing techniques and instruments used for remote measurement of parameters of interest within these waters; (2) develop methods for interpretation of state-of-the-art remote sensing data which are most meaningful to an understanding of processes taking place within near-shore waters; (3) define hardware development requirements and/or system specifications; (4) develop a system combining data from remote and surface measurements which will most efficiently assess conditions in near-shore waters; (5) conduct projects in coordination with appropriate operating agencies to demonstrate applicability of this research to environmental and economic problems.
Fondekar, S.P.; Rao, L.V.G.
the drawback of expensive conventional surveying methods. An airborne remote sensing system used for monitoring and surveillance of oil comprises different sensors such as side-looking airborne radar, synthetic aperture radar, infrared/ultraviolet line scanner...
Papers were presented in four subject areas: applications of remote sensing; data analysis, digital and analog; acquisition systems; and general. Abstracts of individual items from the conference were prepared separately for the data base
Full Text Available For this research, the researchers examine various existing image classification algorithms with the aim of demonstrating how these algorithms can be applied to remote sensing images. These algorithms are broadly divided into supervised...
Philipson, W. R.; Erb, T. L.; Fernandez, D.; Mcleester, J. N.
Cornell's Remote Sensing Program has been involved in a continuing investigation to assess the value of remote sensing for vineyard management. Program staff members have conducted a series of site and crop analysis studies. These include: (1) panchromatic aerial photography for planning artificial drainage in a new vineyard; (2) color infrared aerial photography for assessing crop vigor/health; and (3) color infrared aerial photography and aircraft multispectral scanner data for evaluating yield related factors. These studies and their findings are reviewed.
This book provides up-to-date developments, methods, and techniques in the field of GIS and remote sensing and features articles from internationally renowned authorities on three interrelated perspectives of scaling issues: scale in land surface properties, land surface patterns, and land surface processes. The book is ideal as a professional reference for practicing geographic information scientists and remote sensing engineers as well as a supplemental reading for graduate level students.
El-Baz, F.; Hassan, M.H.A.; Cappellini, V.
The purpose of the Workshop was to study in depth the application of remote sensing technology to the fields of archaeology, astronomy, geography, geology, and physics. Some emphasis was placed on utilizing remote sensing methods and techniques in the search for water, mineral and land resources. The Workshop was attended by 90 people from 35 countries. The proceedings of this meeting includes 15 papers, 12 of them have a separate abstract in the INIS Database. Refs, figs and tabs
Batini, C.; Blaschke, T.; Lang, S.; Albrecht, F.; Abdulmutalib, H. M.; Barsi, Á.; Szabó, G.; Kugler, Zs.
The issue of data quality (DQ) is of growing importance in Remote Sensing (RS), due to the widespread use of digital services (incl. apps) that exploit remote sensing data. In this position paper a body of experts from the ISPRS Intercommission working group III/IVb "DQ" identifies, categorises and reasons about issues that are considered as crucial for a RS research and application agenda. This ISPRS initiative ensures to build on earlier work by other organisations such as IEEE, CEOS or GEO, in particular on the meritorious work of the Quality Assurance Framework for Earth Observation (QA4EO) which was established and endorsed by the Committee on Earth Observation Satellites (CEOS) but aims to broaden the view by including experts from computer science and particularly database science. The main activities and outcomes include: providing a taxonomy of DQ dimensions in the RS domain, achieving a global approach to DQ for heterogeneous-format RS data sets, investigate DQ dimensions in use, conceive a methodology for managing cost effective solutions on DQ in RS initiatives, and to address future challenges on RS DQ dimensions arising in the new era of the big Earth data.
Kibler, J.; Ruminski, M. G.
The HMS is a multiplatform remote sensing approach to detecting fires and smoke over the US and adjacent areas of Canada and Mexico that has been in place since June 2002. This system is an integral part of the National Environmental Satellite and Data Information Service (NESDIS) near realtime hazard detection and mitigation efforts. The system utilizes NOAA's Geostationary Operational Environmental Satellites (GOES), Polar Operational Environmental Satellites (POES) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra and Aqua spacecraft. Automated detection algorithms are employed for each of the satellites for the fire detects while smoke is added by a satellite image analyst. In June 2003 the HMS underwent an upgrade. A number of features were added for users of the products generated on the HMS. Sectors covering Alaska and Hawaii were added. The use of Geographic Information System (GIS) shape files for smoke analysis is a new feature. Shape files show the progression and time of a single smoke plume as each analysis is drawn and then updated. The analyst now has the ability to view GOES, POES, and MODIS data in a single loop. This allows the fire analyst the ability to easily confirm a fire in three different data sets. The upgraded HMS has faster satellite looping and gives the analyst the ability to design a false color image for a particular region. The GOES satellites provide a relatively coarse 4 km infrared resolution at satellite subpoint for thermal fire detection but provide the advantage of a rapid update cycle. GOES imagery is updated every 15 minutes utilizing both GOES-10 and GOES-12. POES imagery from NOAA-15, NOAA-16 and NOAA-17 and MODIS from Terra and Aqua are employed with each satellite providing twice per day coverage (more frequent over Alaska). While the frequency of imagery is much less than with GOES the higher resolution of these satellites (1 km along the suborbital track) allows for detection of
Full Text Available In response to the need for generic remote sensing tools to support large-scale agricultural monitoring, we present a new approach for regional-scale mapping of agricultural land-use systems (ALUS based on object-based Normalized Difference Vegetation Index (NDVI time series analysis. The approach consists of two main steps. First, to obtain relatively homogeneous land units in terms of phenological patterns, a principal component analysis (PCA is applied to an annual MODIS NDVI time series, and an automatic segmentation is performed on the resulting high-order principal component images. Second, the resulting land units are classified into the crop agriculture domain or the livestock domain based on their land-cover characteristics. The crop agriculture domain land units are further classified into different cropping systems based on the correspondence of their NDVI temporal profiles with the phenological patterns associated with the cropping systems of the study area. A map of the main ALUS of the Brazilian state of Tocantins was produced for the 2013–2014 growing season with the new approach, and a significant coherence was observed between the spatial distribution of the cropping systems in the final ALUS map and in a reference map extracted from the official agricultural statistics of the Brazilian Institute of Geography and Statistics (IBGE. This study shows the potential of remote sensing techniques to provide valuable baseline spatial information for supporting agricultural monitoring and for large-scale land-use systems analysis.
North, G. W.
Environmental pollution is a problem of international scope and concern. It can be subdivided into problems relating to water, air, or land pollution. Many of the problems in these three categories lend themselves to study and possible solution by remote sensing. Through the use of remote sensing systems and techniques, it is possible to detect and monitor, and in some cases, identify, measure, and study the effects of various environmental pollutants. As a guide for making decisions regarding the use of remote sensors for pollution studies, a special five-dimensional sensor/applications matrix has been designed. The matrix defines an environmental goal, ranks the various remote sensing objectives in terms of their ability to assist in solving environmental problems, lists the environmental problems, ranks the sensors that can be used for collecting data on each problem, and finally ranks the sensor platform options that are currently available.
Cracknell, A P [ed.
Various aspects of remote sensing are discussed. Topics include: the EARTHNET data acquisition, processing, and distribution facility the design and implementation of a digital interactive image processing system geometrical aspects of remote sensing and space cartography remote sensing of a complex surface legal aspects of remote sensing remote sensing of pollution, dust storms, ice masses, and ocean waves and currents use of satellite images for weather forecasting. Notes on field trips and work-sheets for laboratory exercises are included.
Rangzan, K.; Charchi, A.; Abshirini, E.; Dinger, J.
The Pabdeh-Lali Anticline of northern Khuzestan province is located in southwestern Iran and occupies 790 km2. This structure is situated in the Zagros folded belt. As a result of well-developed karst systems in the anticlinal axis, the water supply potential is high and is drained by many peripheral springs. However, there is a scarcity of water for agriculture and population centers on the anticlinal flanks, which imposes a severe problem in terms of area development. This study combines remotely sensed (RS) data and a geographical information system (GIS) into a RSGIS technique to delineate new areas for groundwater development and specific sites for drilling productive water wells. Toward these goals, RS data were used to develop GIS layers for lithology, structural geology, topographic slope, elevation, and drainage density. Field measurements were made to create spring-location and groundwater-quality GIS layers. Subsequently, expert choice and relational methods were used in a GIS environment to conjunctively analyze all layers to delineate preferable regions and 43 individual sites in which to drill water wells. Results indicate that the most preferred areas are, in preferential order, within recent alluvial deposits, the Bakhtiyari Conglomerates, and the Aghajari Sandstone. The Asmari Limestone and other units have much lower potential for groundwater supplies. Potential usefulness of the RSGIS method was indicated when six out of nine producing wells recently drilled by the Khozestan Water and Power Authority (which had no knowledge of this study) were located in areas preferentially selected by this technique.
Alex S. Olpenda
Full Text Available Solar radiation, the radiant energy from the sun, is a driving variable for numerous ecological, physiological, and other life-sustaining processes in the environment. Traditional methods to quantify solar radiation are done either directly (e.g., quantum sensors, or indirectly (e.g., hemispherical photography. This study, however, evaluates literature which utilized remote sensing (RS technologies to estimate various forms of solar radiation or components, thereof under or within forest canopies. Based on the review, light detection and ranging (LiDAR has, so far, been preferably used for modeling light under tree canopies. Laser system’s capability of generating 3D canopy structure at high spatial resolution makes it a reasonable choice as a source of spatial information about light condition in various parts of forest ecosystem. The majority of those using airborne laser system (ALS commonly adopted the volumetric-pixel (voxel method or the laser penetration index (LPI for modeling the radiation, while terrestrial laser system (TLS is preferred for canopy reconstruction and simulation. Furthermore, most of the studies focused only on global radiation, and very few on the diffuse fraction. It was also found out that most of these analyses were performed in the temperate zone, with a smaller number of studies made in tropical areas. Nonetheless, with the continuous advancement of technology and the RS datasets becoming more accessible and less expensive, these shortcomings and other difficulties of estimating the spatial variation of light in the forest are expected to diminish.
Newcomer, Michelle; Kuss, Amber; Kentron, Tyler; Remar, Alex; Choksi, Vivek; Skiles, J. W.
Restoration of the industrial salt flats in the San Francisco Bay, California is an ongoing wetland rehabilitation project. Remote sensing maps of suspended sediment concentration, and other GIS predictor variables were used to model sediment deposition within these recently restored ponds. Suspended sediment concentrations were calibrated to reflectance values from Landsat TM 5 and ASTER using three statistical techniques -- linear regression, multivariate regression, and an Artificial Neural Network (ANN), to map suspended sediment concentrations. Multivariate and ANN regressions using ASTER proved to be the most accurate methods, yielding r2 values of 0.88 and 0.87, respectively. Predictor variables such as sediment grain size and tidal frequency were used in the Marsh Sedimentation (MARSED) model for predicting deposition rates for three years. MARSED results for a fully restored pond show a root mean square deviation (RMSD) of 66.8 mm (<1) between modeled and field observations. This model was further applied to a pond breached in November 2010 and indicated that the recently breached pond will reach equilibrium levels after 60 months of tidal inundation.
Rajesh Bahadur Thapa
Full Text Available This paper examines the spatiotemporal pattern of urbanization in Kathmandu Valley using remote sensing and spatial metrics techniques. The study is based on 33-years of time series data compiled from satellite images. Along with new developments within the city fringes and rural villages in the valley, shifts in the natural environment and newly developed socioeconomic strains between residents are emerging. A highly dynamic spatial pattern of urbanization is observed in the valley. Urban built-up areas had a slow trend of growth in the 1960s and 1970s but have grown rapidly since the 1980s. The urbanization process has developed fragmented and heterogeneous land use combinations in the valley. However, the refill type of development process in the city core and immediate fringe areas has shown a decreasing trend in the neighborhood distances between land use patches, and an increasing trend towards physical connectedness, which indicates a higher probability of homogenous landscape development in the upcoming decades.
In the southern part of the Eastern Desert of Egypt, Landsat Thematic Mapper (ETM+) data and fieldwork was combined with mineralogical and geochemical investigations in order to detect and characterize alteration zones within Pan-African rocks. The processing of Landsat ETM+ data using ratioing (bands 5/7,5/1,4/3 in Red, Green, Blue) showed two different types of alteration zones (type l and 2). Type 1 is close to the ophiolitic ultramafic rocks and type 2 is located within island-arc related metavolcanic rocks at the study areas. Both of these alteration zones are concordant with the main NW-SE structural trend. Mineralogical studies indicate that the alteration zones of type 1 consist mainly of calcite, ankerite, magnesite, dolomite and quartz. Chromian spinel, pyrite, and Ni-bearing sulphides (gersdorffite, pentlandite and polydymite) are the main ore minerals within this zone. Alteration zones of type 2 are strongly potassium-enriched and pyrophyllite, kaolinite, illite, gypsum and quartz occur. The brecciated quartz-veins associated with theses alteration zones consist of quartz, Fe-hydroxides, hematite and native gold. The gold content reaches up to 5 g/t in the alteration zone, while it extends up to 50 g/t in the quartz veins. This study presents a mineralogical characterization of such zones and demonstrates the utility of orbital remote sensing for finding unknown alteration zones in the Eastern Desert and other arid areas with similar host rock lithologies.
Peng, H. Y.; Tseng, K. H.; Chung-Yen, K.; Lin, T. H.; Liao, W. H.; Chen, C. F.
Coastal sea level can be observed as waterline changes along a coastal digital elevation model (DEM). However, most global DEMs, such as the Shuttle Radar Topography Mission (SRTM) DEM with 30 m resolution, provide limited coverage over coastal area due to the impermeability of radar signal over water and the lack of low-tide coincidence. Therefore, we aim to extend to coverage of SRTM DEM for the determination of intertidal zone and to monitor sea-level changes along the entire coastline of Taiwan (>1200km). We firstly collect historical cloud-free images since the 1980s, including Landsat series, SPOT series and Sentinel-2, and then calculate the Modified Normalized Difference Water Index (MNDWI) to identify water pixels. After computing water appearance probability of each pixel, it is converted into actual elevation by introducing the DTU10 tide model for high tide and low tide boundaries. A coastal DEM of intertidal zone is reconstructed and the accuracy is at 50 cm level as compared with in situ DEM built by an unmanned aerial vehicle (UAV). Finally, we use this product to define the up-to-date intertidal zone and estimate sea-level changes by using remote sensing snapshots.
Montgomery, Joshua S. M.
This thesis investigates the ecology of wetlands and associated classification in prairie and boreal environments of Alberta, Canada, using remote sensing technology to enhance classification of wetlands in the province. Objectives of the thesis are divided into two case studies, 1) examining how satellite borne Synthetic Aperture Radar (SAR), optical (RapidEye & SPOT) can be used to evaluate surface water trends in a prairie pothole environment (Shepard Slough); and 2) investigating a data fusion methodology combining SAR, optical and Lidar data to characterize wetland vegetation and surface water attributes in a boreal environment (Utikuma Regional Study Area (URSA)). Surface water extent and hydroperiod products were derived from SAR data, and validated using optical imagery with high accuracies (76-97% overall) for both case studies. High resolution Lidar Digital Elevation Models (DEM), Digital Surface Models (DSM), and Canopy Height Model (CHM) products provided the means for data fusion to extract riparian vegetation communities and surface water; producing model accuracies of (R2 0.90) for URSA, and RMSE of 0.2m to 0.7m at Shepard Slough when compared to field and optical validation data. Integration of Alberta and Canadian wetland classifications systems used to classify and determine economic value of wetlands into the methodology produced thematic maps relevant for policy and decision makers for potential wetland monitoring and policy development.
Branch, B. D.; Raskin, R. G.; Rock, B.; Gagnon, M.; Lecompte, M. A.; Hayden, L. B.
With the nation challenged to comply with Executive Order 12906 and its needs to augment the Science, Technology, Engineering and Mathematics (STEM) pipeline, applied focus on geosciences pipelines issue may be at risk. The Geosciences pipeline may require intentional K-12 standard course of study consideration in the form of project based, science based and evidenced based learning. Thus, the K-12 to geosciences to informatics pipeline may benefit from an earth science experience that utilizes a community based “learning by doing” approach. Terms such as Community GIS, Community Remotes Sensing, and Community Based Ontology development are termed Community Informatics. Here, approaches of interdisciplinary work to promote and earth science literacy are affordable, consisting of low cost equipment that renders GIS/remote sensing data processing skills necessary in the workforce. Hence, informal community ontology development may evolve or mature from a local community towards formal scientific community collaboration. Such consideration may become a means to engage educational policy towards earth science paradigms and needs, specifically linking synergy among Math, Computer Science, and Earth Science disciplines.
This paper focuses on the use of remote sensing for marine oil spill detection and response. The surveillance and monitoring of discharges, and the main elements of effective surveillance are discussed. Tactical emergency response and the requirements for selecting a suitable remote sensing approach, airborne remote sensing systems, and the integration of satellite and airborne imaging are examined. Specifications of satellite surveillance systems potentially usable for oil spill detection, and specifications of airborne remote sensing systems suitable for oil spill detection, monitoring and supplemental actions are tabulated, and a schema of integrated satellite-airborne remote sensing (ISARS) is presented. (UK)
The current state of understanding of the biosphere is reviewed, the major scientific issues to be addressed are discussed, and techniques, existing and in need of development, for the science are evaluated. It is primarily concerned with developing the scientific capabilities of remote sensing for advancing the subject. The global nature of the scientific objectives requires the use of space-based techniques. The capability to look at the Earth as a whole was developed only recently. The space program has provided the technology to study the entire Earth from artificial satellites, and thus is a primary force in approaches to planetary biology. Space technology has also permitted comparative studies of planetary atmospheres and surfaces. These studies coupled with the growing awareness of the effects that life has on the entire Earth, are opening new lines of inquiry in science.
Sensing systems are an important element of mobile teleoperators and robots. This paper discusses certain problems and limitations of vision and other sensing systems with respect to operations in a radiological accident environment. Methods which appear promising for near-term improvements to sensor technology are described. 3 refs
Lazaridou, M. A.; Patmio, E. N.
Earth and its environment are studied by different scientific disciplines as geosciences, science of engineering, social sciences, geography, etc. The study of the above, beyond pure scientific interest, is useful for the practical needs of man. Photogrammetry and Remote Sensing (defined by Statute II of ISPRS) is the art, science, and technology of obtaining reliable information from non-contact imaging and other sensor systems about the Earth and its environment, and other physical objects and of processes through recording, measuring, analyzing and representation. Therefore, according to this definition, photogrammetry and remote sensing can support studies of the above disciplines for acquisition of geoinformation. This paper concerns basic concepts of geosciences (geomorphology, geology, hydrology etc), and the fundamentals of photogrammetry-remote sensing, in order to aid the understanding of the relationship between photogrammetry-remote sensing and geoinformation and also structure curriculum in a brief, concise and coherent way. This curriculum can represent an appropriate research and educational outline and help to disseminate knowledge in various directions and levels. It resulted from our research and educational experience in graduate and post-graduate level (post-graduate studies relative to the protection of environment and protection of monuments and historical centers) in the Lab. of Photogrammetry - Remote Sensing in Civil Engineering Faculty of Aristotle University of Thessaloniki.
.... The LUT methodology works as follows. First, a database of remote-sensing reflectance (R(sub rs) spectra corresponding to various water depths, bottom reflectance spectra, and water-column inherent optical properties...
Frearson, N.; Bell, R. E.; Tinto, K. J.; Zappa, C. J.
The New York Air National Guard [NYANG] provides regular airborne support to the National Science Foundation [NSF] moving science parties and their equipment onto and around the ice-sheets in both polar regions during the respective summer seasons. Icepod has been developed to utilize this readily available resource, providing the aircraft with a modular external pod attached to the rear-paratrooper door on either side of the NYANG's ski-equipped LC-130s. The pod is divided into five separate bays each approximately a 2ft cube within which can be mounted an array of remote sensors. Power, heating, sensor control and data management services are provided to each bay. An Ethernet network is used to transfer commands and data packets between the individual sensors and data acquisition system located inside the aircraft. Data for each sensor is stored on ruggedized and removable hard-drives that can be taken off the aircraft at the end of a flight for further analysis. In its current configuration the pod is equipped for the remote sensing of ice sheets and their margins and the bay's contain two radar systems, radar antennas, a vibration isolated optics bay including a scanning laser, Infra-red camera and high-definition visible wave camera. Sensor data is geo-referenced using GNSS and orientation sensors located inside the pod. A Pyrometer provides the downward looking IR Camera with the current sky temperature. In January 2013, the Icepod system was flight certified at the Stratton air base in Schenectady, New York. The system deployed to Greenland in April and July 2013 to test the instrumentation suite over ice and its ease of deployment with the NYANG. Icepod can be operated in two modes, a traditional dedicated science flight mode and a piggy-back mode. In piggy-back mode science parties and their cargo are delivered to their destinations with Icepod installed but stowed. Once they have been delivered the Icepod is deployed and measurements can be taken on the
Parks, Shawna; Byrnes, Jeffrey; Abdelsalam, Mohamed G.; Laó Dávila, Daniel A.; Atekwana, Estella A.; Atya, Magdy A.
We used multi-map analysis of remote sensing and ancillary data to identify potentially accessible sites for groundwater resources in the Kharga Basin in the Western Desert of Egypt. This basin is dominated by Cretaceous sandstone formations and extends within the Nubian Sandstone Aquifer. It is dissected by N-S and E-W trending faults, possibly acting as conduits for upward migration of groundwater. Analysis of paleo-drainage using Digital Elevation Model (DEM) generated from the Shuttle Radar Topography Mission (SRTM) data shows that the Kharga was a closed basin that might have been the site of a paleo-lake. Lake water recharged the Nubian Sandstone Aquifer during the wetter Holocene time. We generated the following layers for the multi-map analysis: (1) Fracture density map from the interpretation of Landsat Operational Land Imager (OLI), SRTM DEM, and RADARSAT data. (2) Thermal Inertia (TI) map (for moisture content imaging) from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. (3) Hydraulic conductivity map from mapping lithological units using the Landsat OLI and previously published data. (4) Aquifer thickness map from previously published data. We quantitatively ranked the Kharga Basin by considering that regions of high fracture density, high TI, thicker aquifer, and high hydraulic conductivity have higher potential for groundwater accessibility. Our analysis shows that part of the southern Kharga Basin is suitable for groundwater extraction. This region is where N-S and E-W trending faults intersect, has relatively high TI and it is underlain by thick aquifer. However, the suitability of this region for groundwater use will be reduced significantly when considering the changes in land suitability and economic depth to groundwater extraction in the next 50 years.
Full Text Available Model based analysis or explicit definition/listing of all models/assumptions used in the derivation of a pan-sharpening method allows us to understand the rationale or properties of existing methods and shows a way for a proper usage or proposal/selection of new methods ‘better’ satisfying the needs of a particular application. Most existing pan-sharpening methods are based mainly on the two models/assumptions: spectral consistency for high resolution multispectral data (physical relationship between multispectral and panchromatic data in a high resolution scale and spatial consistency for multispectral data (so-called Wald’s protocol first property or relationship between multispectral data in different resolution scales. Two methods, one based on a linear unmixing model and another one based on spatial unmixing, are described/proposed/modified which respect models assumed and thus can produce correct or physically justified fusion results. Earlier mentioned property ‘better’ should be measurable quantitatively, e.g. by means of so-called quality measures. The difficulty of a quality assessment task in multi-resolution image fusion or pan-sharpening is that a reference image is missing. Existing measures or so-called protocols are still not satisfactory because quite often the rationale or assumptions used are not valid or not fulfilled. From a model based view it follows naturally that a quality assessment measure can be defined as a combination of error model residuals using common or general models assumed in all fusion methods. Thus in this paper a comparison of the two earlier proposed/modified pan-sharpening methods is performed. Preliminary experiments based on visual analysis are carried out in the urban area of Munich city for optical remote sensing multispectral data and panchromatic imagery of the WorldView-2 satellite sensor.
The Remote Sensing in Wind Energy Compendium provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind this compendium began in year 2008 at Risø DTU during the first PhD Summer School: Remote Sensing in Wind Energy. Thus...... in the Meteorology and Test and Measurements Programs from the Wind Energy Division at Risø DTU in the PhD Summer Schools. We hope to add more topics in future editions and to update as necessary, to provide a truly state-of-the-art compendium available for people involved in Remote Sensing in Wind Energy....
Surveillance and tracking of oil spills has been a feature of most spill response situations for many years. The simplest and most direct method uses visual observations from an aircraft and hand-plotting of the data on a map. This technique has proven adequate for most small spills and for responses in fair weather. As the size of the spill increases or the weather deteriorates, there is a need to augment visual aerial observations with remote sensing methods. Remote sensing and its associated systems are one of the most technically complex and sophisticated elements of an oil spill response. During the past few years, a number of initiatives have been undertaken to use contemporary electronic and computing systems to develop new and improved remote sensing systems
Al-Naimi, Noora; Al-Ghouti, Mohammad A; Balakrishnan, Perumal
Mangroves are unique ecosystems that dominate tropical and subtropical coastlines around the world. They provide shelter and nursery to wide variety of species such as fish and birds. Around 73 species of mangroves were recognized around the world. In Qatar, there is only one mangrove species Avicennia marina that is predominant along the northeastern coast. Assessing the health of these valuable ecosystems is vital for protection, management, and conservation of those resources. In this study, an integrated approach of chemical and remote sensing analysis was implemented to investigate the current status of the mangrove trees in Al-Khor, Qatar. Fifteen different A. marina trees from different locations in the mangrove forest were examined for their chlorophyll and nitrogen content levels. Soil analysis was also conducted to understand the effect of moisture on nitrogen availability. Results shows that currently, mangroves are in a good status in terms of nitrogen availability and chlorophyll levels which are related and both are key factors for photosynthesis. Remote sensing techniques were used for chlorophyll prediction. The results showed that these methods have the potential to be used for chlorophyll prediction and estimation.
The applicability of the normalized difference water index (NDWI) to the delineation of dam failure-induced floods is demonstrated for the case of the Sparmos dam (Larissa, Central Greece). The approach followed was based on the differentiation of NDWI maps to accurately define the extent of the inundated area over different time spans using multimission Earth observation optical data. Besides using Landsat data, for which the index was initially designed, higher spatial resolution data from Sentinel-2 mission were also successfully exploited. A geospatial analysis approach was then introduced to rapidly identify potentially affected segments of the road network. This allowed for further correlation to actual damages in the following damage assessment and remediation activities. The proposed combination of geographic information systems and remote sensing techniques can be easily implemented by local authorities and civil protection agencies for mapping and monitoring flood events.
Dierssen, Heidi M.; Randolph, Kaylan
The oceans cover over 70% of the earth's surface and the life inhabiting the oceans play an important role in shaping the earth's climate. Phytoplankton, the microscopic organisms in the surface ocean, are responsible for half of the photosynthesis on the planet. These organisms at the base of the food web take up light and carbon dioxide and fix carbon into biological structures releasing oxygen. Estimating the amount of microscopic phytoplankton and their associated primary productivity over the vast expanses of the ocean is extremely challenging from ships. However, as phytoplankton take up light for photosynthesis, they change the color of the surface ocean from blue to green. Such shifts in ocean color can be measured from sensors placed high above the sea on satellites or aircraft and is called "ocean color remote sensing." In open ocean waters, the ocean color is predominantly driven by the phytoplankton concentration and ocean color remote sensing has been used to estimate the amount of chlorophyll a, the primary light-absorbing pigment in all phytoplankton. For the last few decades, satellite data have been used to estimate large-scale patterns of chlorophyll and to model primary productivity across the global ocean from daily to interannual timescales. Such global estimates of chlorophyll and primary productivity have been integrated into climate models and illustrate the important feedbacks between ocean life and global climate processes. In coastal and estuarine systems, ocean color is significantly influenced by other light-absorbing and light-scattering components besides phytoplankton. New approaches have been developed to evaluate the ocean color in relationship to colored dissolved organic matter, suspended sediments, and even to characterize the bathymetry and composition of the seafloor in optically shallow waters. Ocean color measurements are increasingly being used for environmental monitoring of harmful algal blooms, critical coastal habitats
Sims, Daniel A; Brzostek, Edward R; Rahman, Abdullah F; Dragoni, Danilo; Phillips, Richard P
Given that forests represent the primary terrestrial sink for atmospheric CO2 , projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy 'greenness' (e.g., normalized difference vegetation index; NDVI). However, many forests have low spectral sensitivity to water stress (SSWS) - defined here as drought-induced decline in GPP without a change in greenness. Current satellite-derived estimates of GPP use a vapor pressure deficit (VPD) scalar to account for the low SWSS of forests, but fail to capture their responses to water stress. Our objectives were to characterize differences in SSWS among forested and nonforested ecosystems, and to develop an improved framework for predicting the impacts of water stress on GPP in forests with low SSWS. First, we paired two independent drought indices with NDVI data for the conterminous US from 2000 to 2011, and examined the relationship between water stress and NDVI. We found that forests had lower SSWS than nonforests regardless of drought index or duration. We then compared satellite-derived estimates of GPP with eddy-covariance observations of GPP in two deciduous broadleaf forests with low SSWS: the Missouri Ozark (MO) and Morgan Monroe State Forest (MMSF) AmeriFlux sites. Model estimates of GPP that used VPD scalars were poorly correlated with observations of GPP at MO (r(2) = 0.09) and MMSF (r(2) = 0.38). When we included the NDVI responses to water stress of adjacent ecosystems with high SSWS into a model based solely on temperature and greenness, we substantially improved predictions of GPP at MO (r(2) = 0.83) and for a severe drought year at the MMSF (r(2) = 0.82). Collectively, our results suggest that large-scale estimates of GPP that capture variation in SSWS among ecosystems could improve predictions of C uptake by forests under drought. © 2014 John Wiley & Sons
Miodrag D. Regodić
Full Text Available There has always been a need to directly perceive and study the events whose extent is beyond people's possibilities. In order to get new data and to make observations and studying much more objective in comparison with past syntheses - a new method of examination called remote sensing has been adopted. The paper deals with the principles and elements of remote sensing, as well as with the basic aspects of using remote research in examining meteorological (weather parameters and the conditions of the atmosphere. The usage of satellite images is possible in all phases of the global and systematic research of different natural phenomena when airplane and satellite images of different characteristics are used and their analysis and interpretation is carried out by viewing and computer added procedures. Introduction Remote sensing of the Earth enables observing and studying global and local events that occur on it. Satellite images are nowadays used in geology, agriculture, forestry, geodesy, meteorology, spatial and urbanism planning, designing of infrastructure and other objects, protection from natural and technological catastrophes, etc. It it possible to use satellite images in all phases of global and systematic research of different natural phenomena. Basics of remote sensing Remote sensing is a method of the acquisition and interpretation of information about remote objects without making a physical contact with them. The term Daljinska detekcija is a literal translation of the English term Remote Sensing. In French it isTeledetection, in German - Fernerkundung, in Russian - дистанционие иследования. We also use terms such as: remote survailance, remote research, teledetection, remote methods, and distance research. The basic elements included in Remote Sensing are: object, electromagnetic energy, sensor, platform, image, analysis, interpretation and the information (data, fact. Usage of satellite remote research in
The purpose of this publication is to provide the reader with a basis for making an intelligent approach to the use of remote sensing in uranium exploration. It includes: A description of the various techniques; specific applications in view of exploration strategy and selection of appropriate techniques, and some examples of applications; availability and costs; a bibliography
The purpose of this publication is to provide the reader with a basis for making an intelligent approach to the use of remote sensing in uranium exploration. It includes: A description of the various techniques; specific applications in view of exploration strategy and selection of appropriate techniques, and some examples of applications; availability and costs; a bibliography.
White, P. G.
Remote sensing, as a tool to aid in the control of water pollution, offers a means of making rapid, economical surveys of areas that are relatively inaccessible on the ground. At the same time, it offers the only practical means of mapping pollution patterns that cover large areas. Detection of oil slicks, thermal pollution, sewage, and algae are discussed.
Kahn, Ralph A.
Aerosols are solid or liquid particles suspended in the air, and those observed by satellite remote sensing are typically between about 0.05 and 10 microns in size. (Note that in traditional aerosol science, the term "aerosol" refers to both the particles and the medium in which they reside, whereas for remote sensing, the term commonly refers to the particles only. In this article, we adopt the remote-sensing definition.) They originate from a great diversity of sources, such as wildfires, volcanoes, soils and desert sands, breaking waves, natural biological activity, agricultural burning, cement production, and fossil fuel combustion. They typically remain in the atmosphere from several days to a week or more, and some travel great distances before returning to Earth's surface via gravitational settling or washout by precipitation. Many aerosol sources exhibit strong seasonal variability, and most experience inter-annual fluctuations. As such, the frequent, global coverage that space-based aerosol remote-sensing instruments can provide is making increasingly important contributions to regional and larger-scale aerosol studies.
Lausch, Angela; Pause, Marion; Merbach, Ines; Zacharias, Steffen; Doktor, Daniel; Volk, Martin; Seppelt, Ralf
Remote sensing is an important tool for studying patterns in surface processes on different spatiotemporal scales. However, differences in the spatiospectral and temporal resolution of remote sensing data as well as sensor-specific surveying characteristics very often hinder comparative analyses and effective up- and downscaling analyses. This paper presents a new methodical framework for combining hyperspectral remote sensing data on different spatial and temporal scales. We demonstrate the potential of using the "One Sensor at Different Scales" (OSADIS) approach for the laboratory (plot), field (local), and landscape (regional) scales. By implementing the OSADIS approach, we are able (1) to develop suitable stress-controlled vegetation indices for selected variables such as the Leaf Area Index (LAI), chlorophyll, photosynthesis, water content, nutrient content, etc. over a whole vegetation period. Focused laboratory monitoring can help to document additive and counteractive factors and processes of the vegetation and to correctly interpret their spectral response; (2) to transfer the models obtained to the landscape level; (3) to record imaging hyperspectral information on different spatial scales, achieving a true comparison of the structure and process results; (4) to minimize existing errors from geometrical, spectral, and temporal effects due to sensor- and time-specific differences; and (5) to carry out a realistic top- and downscaling by determining scale-dependent correction factors and transfer functions. The first results of OSADIS experiments are provided by controlled whole vegetation experiments on barley under water stress on the plot scale to model LAI using the vegetation indices Normalized Difference Vegetation Index (NDVI) and green NDVI (GNDVI). The regression model ascertained from imaging hyperspectral AISA-EAGLE/HAWK (DUAL) data was used to model LAI. This was done by using the vegetation index GNDVI with an R (2) of 0.83, which was
Full Text Available In order to adapt different scale land cover segmentation, an optimized approach under the guidance of k-means clustering for multi-scale segmentation is proposed. At first, small scale segmentation and k-means clustering are used to process the original images; then the result of k-means clustering is used to guide objects merging procedure, in which Otsu threshold method is used to automatically select the impact factor of k-means clustering; finally we obtain the segmentation results which are applicable to different scale objects. FNEA method is taken for an example and segmentation experiments are done using a simulated image and a real remote sensing image from GeoEye-1 satellite, qualitative and quantitative evaluation demonstrates that the proposed method can obtain high quality segmentation results.
Yitayew, M.; Didan, K.; Barreto-munoz, A.
The Nile Basin is one of the world's water resources hotspot that is home to over 437 million people in ten riparian countries with 54% or 238 millions live directly within the basin. The basin like all other basins of the world is facing water resources challenges exacerbated by climate change and increased demand. Nowadays any water resource management action in the basin has to assess the impacts of climate change to be able to predict future water supply and also to help in the negotiation process. Presently, there is a lack of basin wide weather networks to understand sensitivity of the vegetation cover to the impacts of climate change. Vegetation plays major economic and ecological functions in the basin and provides key services ranging from pastoralism, agricultural production, firewood, habitat and food sources for the rich wildlife, as well as a major role in the carbon cycle and climate regulation of the region. Under the threat of climate change and the incessant anthropogenic pressure the distribution and services of the region's ecosystems are projected to change The goal of this work is to assess and characterize how the basin vegetation productivity, distribution, and phenology have changed over the last 30+ years and what are the key climatic drivers of this change. This work makes use of a newly generated multi-sensor long-term land surface data set about vegetation and phenology. Vegetation indices derived from remotely sensed surface reflectance data are commonly used to characterize phenology or vegetation dynamics accurately and with enough spatial and temporal resolution to support change detection. We used more than 30 years of vegetation index and growing season data from AVHRR and MODIS sensors compiled by the Vegetation Index and Phenology laboratory (VIP LAB) at the University of Arizona. Available climate data about precipitation and temperature for the corresponding 30 years period is also used for this analysis. We looked at the
Bethel, Glenn R.
A viewgraph presentation of remote sensing imagery within the USDA is shown. USDA Aerial Photography, Digital Sensors, Hurricane imagery, Remote Sensing Sources, Satellites used by Foreign Agricultural Service, Landsat Acquisitions, and Aerial Acquisitions are also shown.
Remote Sensing has started to institute a “Best Paper” award to recognize the most outstanding papers in the area of remote sensing techniques, design and applications published in Remote Sensing. We are pleased to announce the first “Remote Sensing Best Paper Award” for 2013. Nominations were selected by the Editor-in-Chief and selected editorial board members from among all the papers published in 2009. Reviews and research papers were evaluated separately.
Davitt, A. W. D.; Winter, J.; McDonald, K. C.; Escobar, V. M.; Steiner, N.
The monitoring of staple and high-value crops is important for maintaining food security. The recent launch of numerous remote sensing satellites has created the ability to monitor vast amounts of crop lands, continuously and in a timely manner. This monitoring provides users with a wealth of information on various crop types over different regions of the world. However, a challenge still remains on how to best quantify and interpret the crop and surface characteristics that are measured by visible, near-infrared, and active and passive microwave radar. Currently, two NASA funded projects are examining the ability to monitor different types of crops in California with different remote sensing platforms. The goal of both projects is to develop a cost-effective monitoring tool for use by vineyard and crop managers. The first project is designed to examine the capability to monitor vineyard water management and soil moisture in Sonoma County using Soil Moisture Active Passive (SMAP), Sentinel-1A and -2, and Landsat-8. The combined mission products create thorough and robust measurements of surface and vineyard characteristics that can potentially improve the ability to monitor vineyard health. Incorporating the Michigan Microwave Canopy Scattering (MIMICS), a radiative transfer model, enables us to better understand surface and vineyard features that influence radar measurements from Sentinel-1A. The second project is a blended approach to analyze corn, rice, and wheat growth using Sentinel-1A products with Decision Support System for Agrotechnology Transfer (DSSAT) and MIMICS models. This project aims to characterize the crop structures that influence Sentinel-1A radar measurements. Preliminary results have revealed the corn, rice, and wheat structures that influence radar measurements during a growing season. The potential of this monitoring tool can be used for maintaining food security. This includes supporting sustainable irrigation practices, identifying crop
This volume contains the proceedings of SPIE's remote sensing symposium which was held September 22--24, 1998, in Barcelona, Spain. Topics of discussion include the following: calibration techniques for soil moisture measurements; remote sensing of grasslands and biomass estimation of meadows; evaluation of agricultural disasters; monitoring of industrial and natural radioactive elements; and remote sensing of vegetation and of forest fires
Cartwright, Jennifer M.; Johnson, Henry M.
Spring‐fed wetlands are ecologically important habitats in arid and semi‐arid regions. Springs have been suggested as possible hydrologic refugia from droughts and climate change; however, springs that depend on recent precipitation or snowmelt for recharge may be vulnerable to warming and drought intensification. Springs that are expected to maintain their ecohydrologic function in a warmer, drier climate may be priorities for conservation and restoration. Identifying such springs is difficult because many springs lack hydrologic records of adequate temporal extent and resolution to assess their resilience to water cycle changes. This study demonstrates proof‐of‐concept for the assessment of certain spring types (i.e., helocrene, hypocrene, and hillslope springs) in terms of hydrologic and ecological resilience to climatic water stress using freely available remote‐sensing and climate data. We used the Normalized Difference Vegetation Index (NDVI) from 1985 through 2011 to delineate surface‐moisture zones (SMZs) associated with 39 clusters of 172 springs in a montane sage‐steppe landscape in southeastern Oregon, USA. We developed and synthesized seven NDVI‐based indicators of SMZ resilience to interannual changes in water availability: (1) mean and (2) standard deviation of July NDVI; (3) mean difference in July NDVI and (4) difference in coefficient of variation for July NDVI between each SMZ and its surrounding watershed; (5) response of SMZ July NDVI to 90‐day antecedent precipitation; (6) response of SMZ July NDVI to the previous winter's snowpack; and (7) range of NDVI values from an exceptionally wet year followed by three dry years. Because all resilience indicators were highly inter‐correlated, we derived an overall metric of SMZ resilience using principal components analysis that accounted for 66% of total variance. This overall resilience score was positively correlated with SMZ elevation, slope, mean annual precipitation, and with
Chen, Huili; Liang, Zhongyao; Liu, Yong; Liang, Qiuhua; Xie, Shuguang
, with the SCS-CN model as a rainfall-runoff generator and the two-dimensional hydraulic model implementing the routing scheme for surface runoff; and (c) The spatial combination between crop yield losses and flood dynamics on a grid scale can be used to investigate the relationship between the intensity of flood characteristics and associated loss extent. The modeling framework was applied for a 50-year return period flood that occurred in Jilin province, Northeast China, which caused large agricultural losses in August 2013. The modeling results indicated that (a) the flow velocity was the most influential factor that caused spring corn, rice and soybean yield losses from extreme storm event in the mountainous regions; (b) the power function archived the best results that fit the velocity-loss relationship for mountainous areas; and (c) integrated remote sensing imagery and two-dimensional hydraulic modeling approach are helpful for evaluating the influence of historical flood event on crop production and investigating the relationship between flood characteristics and crop yield losses.
Champollion, N; Benveniste, J; Chen, J
This book is a collection of overview articles showing how space-based observations, combined with hydrological modeling, have considerably improved our knowledge of the continental water cycle and its sensitivity to climate change. Two main issues are highlighted: (1) the use in combination of space observations for monitoring water storage changes in river basins worldwide, and (2) the use of space data in hydrological modeling either through data assimilation or as external constraints. The water resources aspect is also addressed, as well as the impacts of direct anthropogenic forcing on land hydrology (e.g. ground water depletion, dam building on rivers, crop irrigation, changes in land use and agricultural practices, etc.). Remote sensing observations offer important new information on this important topic as well, which is highly useful for achieving water management objectives. Over the past 15 years, remote sensing techniques have increasingly demonstrated their capability to monitor components of th...
Full Text Available using state of the art Light Detection And Ranging (LiDAR) instrumentation and other active and passive remote sensing tools. First “Lidar Field Campaign” • 2-day measurement campaign at University of Pretoria • First 23-hour continuous measurement... head2rightCirrus cloud morphology and dynamics. Atmospheric Research in Southern Africa and Indian Ocean (ARSAIO) Slide 24 © CSIR 2008 www.csir.co.za Middle atmosphere dynamics and thermal structure: comparative studies from...
Clarke, Keith C.; Scepan, Joseph; Hemphill, Jeffrey; Herold, Martin; Husak, Gregory; Kline, Karen; Knight, Kevin
This document is the final report summarizing research conducted by the Remote Sensing Research Unit, Department of Geography, University of California, Santa Barbara under National Aeronautics and Space Administration Research Grant NAG5-10457. This document describes work performed during the period of 1 March 2001 thorough 30 September 2002. This report includes a survey of research proposed and performed within RSRU and the UCSB Geography Department during the past 25 years. A broad suite of RSRU research conducted under NAG5-10457 is also described under themes of Applied Research Activities and Information Science Research. This research includes: 1. NASA ESA Research Grant Performance Metrics Reporting. 2. Global Data Set Thematic Accuracy Analysis. 3. ISCGM/Global Map Project Support. 4. Cooperative International Activities. 5. User Model Study of Global Environmental Data Sets. 6. Global Spatial Data Infrastructure. 7. CIESIN Collaboration. 8. On the Value of Coordinating Landsat Operations. 10. The California Marine Protected Areas Database: Compilation and Accuracy Issues. 11. Assessing Landslide Hazard Over a 130-Year Period for La Conchita, California Remote Sensing and Spatial Metrics for Applied Urban Area Analysis, including: (1) IKONOS Data Processing for Urban Analysis. (2) Image Segmentation and Object Oriented Classification. (3) Spectral Properties of Urban Materials. (4) Spatial Scale in Urban Mapping. (5) Variable Scale Spatial and Temporal Urban Growth Signatures. (6) Interpretation and Verification of SLEUTH Modeling Results. (7) Spatial Land Cover Pattern Analysis for Representing Urban Land Use and Socioeconomic Structures. 12. Colorado River Flood Plain Remote Sensing Study Support. 13. African Rainfall Modeling and Assessment. 14. Remote Sensing and GIS Integration.
Wilson, H.; Cary, T. K.; Goward, S. N.
It is noted that within many geography departments remote sensing is viewed as a mere technique a student should learn in order to carry out true geographic research. This view inhibits both students and faculty from investigation of remotely sensed data as a new source of geographic knowledge that may alter our understanding of the Earth. The tendency is for geographers to accept these new data and analysis techniques from engineers and mathematicians without questioning the accompanying premises. This black-box approach hinders geographic applications of the new remotely sensed data and limits the geographer's contribution to further development of remote sensing observation systems. It is suggested that geographers contribute to the development of remote sensing through pursuit of basic research. This research can be encouraged, particularly among students, by demonstrating the links between geographic theory and remotely sensed observations, encouraging a healthy skepticism concerning the current understanding of these data.
Pena, A.; Bay Hasager, C.; Lange, J. [Technical Univ. of Denmark. DTU Wind Energy, DTU Risoe Campus, Roskilde (Denmark) (and others
The Remote Sensing in Wind Energy report provides a description of several topics and it is our hope that students and others interested will learn from it. The idea behind it began in year 2008 at DTU Wind Energy (formerly Risoe) during the first PhD Summer School: Remote Sensing in Wind Energy. Thus it is closely linked to the PhD Summer Schools where state-of-the-art is presented during the lecture sessions. The advantage of the report is to supplement with in-depth, article style information. Thus we strive to provide link from the lectures, field demonstrations, and hands-on exercises to theory. The report will allow alumni to trace back details after the course and benefit from the collection of information. This is the third edition of the report (first externally available), after very successful and demanded first two, and we warmly acknowledge all the contributing authors for their work in the writing of the chapters, and we also acknowledge all our colleagues in the Meteorology and Test and Measurements Sections from DTU Wind Energy in the PhD Summer Schools. We hope to continue adding more topics in future editions and to update and improve as necessary, to provide a truly state-of-the-art 'guideline' available for people involved in Remote Sensing in Wind Energy. (Author)
Evan Brooks; Valerie Thomas; Wynne Randolph; John Coulston
With the advent of free Landsat data stretching back decades, there has been a surge of interest in utilizing remotely sensed data in multitemporal analysis for estimation of biophysical parameters. Such analysis is confounded by cloud cover and other image-specific problems, which result in missing data at various aperiodic times of the year. While there is a wealth...
Gerstl, S.A.; Cooke, B.J.; Henderson, B.G.; Love, S.P.; Zardecki, A.
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The science and technology of satellite remote sensing is an emerging interdisciplinary field that is growing rapidly with many global and regional applications requiring quantitative sensing of earth`s surface features as well as its atmosphere from space. It is possible today to resolve structures on the earth`s surface as small as one meter from space. If this high spatial resolution is coupled with high spectral resolution, instant object identification can also be achieved. To interpret these spectral signatures correctly, it is necessary to perform a computational correction on the satellite imagery that removes the distorting effects of the atmosphere. This project studied such new concepts and applied innovative new approaches in remote sensing science.
McCarthy, Timothy; Farrell, Ronan; Curtis, Andrew; Fotheringham, A. Stewart
Video imagery can be acquired from aerial, terrestrial and marine based platforms and has been exploited for a range of remote sensing applications over the past two decades. Examples include coastal surveys using aerial video, routecorridor infrastructures surveys using vehicle mounted video cameras, aerial surveys over forestry and agriculture, underwater habitat mapping and disaster management. Many of these video systems are based on interlaced, television standards such as North America's NTSC and European SECAM and PAL television systems that are then recorded using various video formats. This technology has recently being employed as a front-line, remote sensing technology for damage assessment post-disaster. This paper traces the development of spatial video as a remote sensing tool from the early 1980s to the present day. The background to a new spatial-video research initiative based at National University of Ireland, Maynooth, (NUIM) is described. New improvements are proposed and include; low-cost encoders, easy to use software decoders, timing issues and interoperability. These developments will enable specialists and non-specialists collect, process and integrate these datasets within minimal support. This integrated approach will enable decision makers to access relevant remotely sensed datasets quickly and so, carry out rapid damage assessment during and post-disaster.
Zhu, Xiaohua; Li, Chuanrong; Tang, Lingli
Leaf area index (LAI) is a key structural characteristic of vegetation and plays a significant role in global change research. Several methods and remotely sensed data have been evaluated for LAI estimation. This study aimed to evaluate the suitability of the look-up-table (LUT) approach for crop LAI retrieval from Satellite Pour l'Observation de la Terre (SPOT)-5 data and establish an LUT approach for LAI inversion based on scale information. The LAI inversion result was validated by in situ LAI measurements, indicating that the LUT generated based on the PROSAIL (PROSPECT+SAIL: properties spectra + scattering by arbitrarily inclined leaves) model was suitable for crop LAI estimation, with a root mean square error (RMSE) of ˜0.31m2 / m2 and determination coefficient (R2) of 0.65. The scale effect of crop LAI was analyzed based on Taylor expansion theory, indicating that when the SPOT data aggregated by 200 × 200 pixel, the relative error is significant with 13.7%. Finally, an LUT method integrated with scale information was proposed in this article, improving the inversion accuracy with RMSE of 0.20 m2 / m2 and R2 of 0.83.
Leptoukh, G.; Zubko, V.; Gopalan, A.; Khayat, M.
We describe Giovanni, the NASA Goddard developed online visualization and analysis tool that allows users explore various phenomena without learning remote sensing data formats and downloading voluminous data. Using MODIS aerosol data as an example, we formulate an approach to the data fusion for Giovanni to further enrich online multi-sensor remote sensing data comparison and analysis.
Durand, Philippe; Brunet, Gerard; Ghorbanzadeh, Dariush; Jaupi, Luan
In this paper, we summarize and compare two different approaches used by the authors, to classify different natural textures. The first approach, which is simple and inexpensive in computing time, uses a data bank image and an expert system able to classify different textures from a number of rules established by discipline specialists. The second method uses the same database and a neural networks approach.
Ahmad, T.; Hayat, M.F.; Afzal, M.; Asif, H.M.S.; Asif, K.H.
Remote Sensing Application (RSA) is important as one of the critical enabler of e-systems such as e- governments, e-commerce, and e-sciences. In this study, we argued that owning to the specialized needs of RSA such as volatility and interactive nature, a customized Software Engineering (SE) approach should be adapted for their development. Based on this argument we have also identified the shortcomings of the conventional SE approaches and the classical waterfall software development life cycle model. In this study, we have proposed a modification to the classical waterfall software development life cycle model for proposing a customized software development Framework for RSAs. We have identified four (4) different types of changes that can occur to an already developed RS application. The proposed framework was capable to incorporate all four types of changes. Remote Sensing, software engineering, functional requirements, types of changes. (author)
Full Text Available Stress in forest ecosystems (FES occurs as a result of land-use intensification, disturbances, resource limitations or unsustainable management, causing changes in forest health (FH at various scales from the local to the global scale. Reactions to such stress depend on the phylogeny of forest species or communities and the characteristics of their impacting drivers and processes. There are many approaches to monitor indicators of FH using in-situ forest inventory and experimental studies, but they are generally limited to sample points or small areas, as well as being time- and labour-intensive. Long-term monitoring based on forest inventories provides valuable information about changes and trends of FH. However, abrupt short-term changes cannot sufficiently be assessed through in-situ forest inventories as they usually have repetition periods of multiple years. Furthermore, numerous FH indicators monitored in in-situ surveys are based on expert judgement. Remote sensing (RS technologies offer means to monitor FH indicators in an effective, repetitive and comparative way. This paper reviews techniques that are currently used for monitoring, including close-range RS, airborne and satellite approaches. The implementation of optical, RADAR and LiDAR RS-techniques to assess spectral traits/spectral trait variations (ST/STV is described in detail. We found that ST/STV can be used to record indicators of FH based on RS. Therefore, the ST/STV approach provides a framework to develop a standardized monitoring concept for FH indicators using RS techniques that is applicable to future monitoring programs. It is only through linking in-situ and RS approaches that we will be able to improve our understanding of the relationship between stressors, and the associated spectral responses in order to develop robust FH indicators.
Full Text Available Atmospheric aerosols impact air quality and global climate. Space based measurements are the best way to observe their spatial and temporal distributions, and can also be used to gain better understanding of their chemical, physical and optical properties. Aerosol composition is the key parameter affecting the refractive index, which determines how much radiation is scattered and absorbed. Composition of aerosols is unfortunately not measured by state of the art satellite remote sounders. Here we use high resolution infrared measurements for aerosol type differentiation, exploiting, in that part of spectrum, the dependency of their refractive index on wavelength. We review existing detection methods and present a unified detection method based on linear discrimination analysis. We demonstrate this method on measurements of the Infrared Atmospheric Sounding Interferometer (IASI and five different aerosol types, namely volcanic ash, windblown sand, sulfuric acid droplets, ammonium sulfate and smoke particles. We compare these with traditional MODIS AOD measurements. The detection of the last three types is unprecedented in the infrared in nadir mode, but is very promising, especially for sulfuric acid droplets which are detected in the lower troposphere and up to 6 months after injection in the upper troposphere/lower stratosphere.
Full Text Available In this paper, I describe a set of procedures that automate forest disturbance mapping using a pair of Landsat images. The approach is built on the traditional pair-wise change detection method, but is designed to extract training data without user interaction and uses a robust classification algorithm capable of handling incorrectly labeled training data. The steps in this procedure include: i creating masks for water, non-forested areas, clouds, and cloud shadows; ii identifying training pixels whose value is above or below a threshold defined by the number of standard deviations from the mean value of the histograms generated from local windows in the short-wave infrared (SWIR difference image; iii filtering the original training data through a number of classification algorithms using an n-fold cross validation to eliminate mislabeled training samples; and finally, iv mapping forest disturbance using a supervised classification algorithm. When applied to 17 Landsat footprints across the U.S. at five-year intervals between 1985 and 2010, the proposed approach produced forest disturbance maps with 80 to 95% overall accuracy, comparable to those obtained from traditional approaches to forest change detection. The primary sources of mis-classification errors included inaccurate identification of forests (errors of commission, issues related to the land/water mask, and clouds and cloud shadows missed during image screening. The approach requires images from the peak growing season, at least for the deciduous forest sites, and cannot readily distinguish forest harvest from natural disturbances or other types of land cover change. The accuracy of detecting forest disturbance diminishes with the number of years between the images that make up the image pair. Nevertheless, the relatively high accuracies, little or no user input needed for processing, speed of map production, and simplicity of the approach make the new method especially practical for
Wolter, Andrea Elaine
I apply a forensic, multidisciplinary approach that integrates engineering geology field investigations, engineering geomorphology mapping, long-range terrestrial photogrammetry, and a numerical modelling toolbox to two large rock slope failures to study their causes, initiation, kinematics, and dynamics. I demonstrate the significance of endogenic and exogenic processes, both separately and in concert, in contributing to landscape evolution and conditioning slopes for failure, and use geomor...
Peri, Frank; Volz, Stephen
NASA's Earth Venture class (EV) of mission are competitively selected, Principal Investigator (PI) led, relatively low cost and narrowly focused in scientific scope. Investigations address a full spectrum of earth science objectives, including studies of the atmosphere, oceans, land surface, polar ice regions, and solid Earth. EV has three program elements: EV-Suborbital (EVS) are suborbital/airborne investigations; EV-Mission (EVM) element comprises small complete spaceborne missions; and EV-Instrument (EVI) element develops spaceborne instruments for flight as missions-of-opportunity (MoO). To ensure the success of EV, the management approach of each element is tailored according to the specific needs of the element.
Full Text Available Predicting freshwater resources is a major concern in West Africa, where large parts of the population depend on rain-fed subsistence agriculture. However, a steady decline in the availability of in-situ measurements of climatic and hydrologic variables makes it difficult to simulate water resource availability with hydrological models. In this study, a modeling framework was set up for sparsely-gauged catchments in West Africa using the Soil and Water Assessment Tool (SWAT, whilst largely relying on remote sensing and reanalysis inputs. The model was calibrated using two different strategies and validated using discharge measurements. New in this study is the use of a multi-objective validation conducted to further investigate the performance of the model, where simulated actual evapotranspiration, soil moisture, and total water storage were evaluated using remote sensing data. Results show that the model performs well (R2 calibration: 0.52 and 0.51; R2 validation: 0.63 and 0.61 and the multi-objective validation reveals good agreement between predictions and observations. The study reveals the potential of using remote sensing data in sparsely-gauged catchments, resulting in good performance and providing data for evaluating water balance components that are not usually validated. The modeling framework presented in this study is the basis for future studies, which will address model response to extreme drought and flood events and further examine the coincidence with Gravity Recovery and Climate Experiment (GRACE total water storage retrievals.
Contents: Remote sensing of wind shear and the theory and development of acoustic doppler; Wind studies; A comparison of methods for the remote detection of winds in the airport environment; Acoustic doppler system development; System calibration; Airport operational tests.
Nansen, Christian; Elliott, Norman
Remote sensing describes the characterization of the status of objects and/or the classification of their identity based on a combination of spectral features extracted from reflectance or transmission profiles of radiometric energy. Remote sensing can be benchtop based, and therefore acquired at a high spatial resolution, or airborne at lower spatial resolution to cover large areas. Despite important challenges, airborne remote sensing technologies will undoubtedly be of major importance in optimized management of agricultural systems in the twenty-first century. Benchtop remote sensing applications are becoming important in insect systematics and in phenomics studies of insect behavior and physiology. This review highlights how remote sensing influences entomological research by enabling scientists to nondestructively monitor how individual insects respond to treatments and ambient conditions. Furthermore, novel remote sensing technologies are creating intriguing interdisciplinary bridges between entomology and disciplines such as informatics and electrical engineering.
Dierssen, Heidi M
Phytoplankton biomass and productivity have been continuously monitored from ocean color satellites for over a decade. Yet, the most widely used empirical approach for estimating chlorophyll a (Chl) from satellites can be in error by a factor of 5 or more. Such variability is due to differences in absorption and backscattering properties of phytoplankton and related concentrations of colored-dissolved organic matter (CDOM) and minerals. The empirical algorithms have built-in assumptions that follow the basic precept of biological oceanography--namely, oligotrophic regions with low phytoplankton biomass are populated with small phytoplankton, whereas more productive regions contain larger bloom-forming phytoplankton. With a changing world ocean, phytoplankton composition may shift in response to altered environmental forcing, and CDOM and mineral concentrations may become uncoupled from phytoplankton stocks, creating further uncertainty and error in the empirical approaches. Hence, caution is warranted when using empirically derived Chl to infer climate-related changes in ocean biology. The Southern Ocean is already experiencing climatic shifts and shows substantial errors in satellite-derived Chl for different phytoplankton assemblages. Accurate global assessments of phytoplankton will require improved technology and modeling, enhanced field observations, and ongoing validation of our "eyes in space."
Lou, Hezhen; Yang, Shengtian; Zhao, Changsen; Shi, Liuhua; Wu, Linna; Wang, Yue; Wang, Zhiwei
The detection of critical source areas (CSAs) is a key step in managing soil phosphorus (P) loss and preventing the long-term eutrophication of water bodies at regional scale. Most related studies, however, focus on a local scale, which prevents a clear understanding of the spatial distribution of CSAs for soil P loss at regional scale. Moreover, the continual, long-term variation in CSAs was scarcely reported. It is impossible to identify the factors driving the variation in CSAs, or to collect land surface information essential for CSAs detection, by merely using the conventional methodologies at regional scale. This study proposes a new regional-scale approach, based on three satellite sensors (ASTER, TM/ETM and MODIS), that were implemented successfully to detect CSAs at regional scale over 15years (2000-2014). The approach incorporated five factors (precipitation, slope, soil erosion, land use, soil total phosphorus) that drive soil P loss from CSAs. Results show that the average area of critical phosphorus source areas (CPSAs) was 15,056km 2 over the 15-year period, and it occupied 13.8% of the total area, with a range varying from 1.2% to 23.0%, in a representative, intensive agricultural area of China. In contrast to previous studies, we found that the locations of CSAs with P loss are spatially variable, and are more dispersed in their distribution over the long term. We also found that precipitation acts as a key driving factor in the variation of CSAs at regional scale. The regional-scale method can provide scientific guidance for managing soil phosphorus loss and preventing the long-term eutrophication of water bodies at regional scale, and shows great potential for exploring factors that drive the variation in CSAs at global scale. Copyright © 2016 Elsevier B.V. All rights reserved.
Progress is reported on three tasks designed to develop remote sensing beach reconnaissance techniques applicable to the benthic, beach intertidal...and beach upland zones. Task 1 is designed to develop remote sensing indicators of important beach composition and physical parameters which will...ultimately prove useful in models to predict beach conditions. Task 2 is designed to develop remote sensing techniques for survey of bottom features in
Polarimeter for Remote Sensing Studies 5b. GRANT NUMBER FA9550-08-1-0295 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 1. Scott Tyo 5e. TASK...and tested at the University of Arizona, and preliminary images are shown in this final report. 15. SUBJECT TERMS Remote Sensing , polarimetry 16...7.0 LWIR Microgrid Polarimeter for Remote Sensing Studies J. Scott Tyo College of Optical Sciences University of Arizona Tucson, AZ, 85721 tyo
Chern, Jeng-Shing; Ling, Jer; Weng, Shui-Lin
FORMOSAT-2 is Taiwan's first remote sensing satellite (RSS). It was launched on 20 May 2004 with five-year mission life and a very unique mission orbit at 891 km altitude. This orbit gives FORMOSAT-2 the daily revisit feature and the capability of imaging the Arctic and Antarctic regions due to the high enough altitude. For more than three years, FORMOSAT-2 has performed outstanding jobs and its global effectiveness is evidenced in many fields such as public education in Taiwan, Earth science and ecological niche research, preservation of the world heritages, contribution to the International Charter: space and major disasters, observation of suspected North Korea and Iranian nuclear facilities, and scientific observation of the atmospheric transient luminous events (TLEs). In order to continue the provision of earth observation images from space, the National Space Organization (NSPO) of Taiwan started to work on the second RSS from 2005. This second RSS will also be Taiwan's first indigenous satellite. Both the bus platform and remote sensing instrument (RSI) shall be designed and manufactured by NSPO and the Instrument Technology Research Center (ITRC) under the supervision of the National Applied Research Laboratories (NARL). Its onboard computer (OBC) shall use Taiwan's indigenous LEON-3 central processing unit (CPU). In order to achieve cost effective design, the commercial off the shelf (COTS) components shall be widely used. NSPO shall impose the up-screening/qualification and validation/verification processes to ensure their normal functions for proper operations in the severe space environments.
Introduction to Remote Sensing Principles and Concepts provides a comprehensive student introduction to both the theory and application of remote sensing. This textbook* introduces the field of remote sensing and traces its historical development and evolution* presents detailed explanations of core remote sensing principles and concepts providing the theory required for a clear understanding of remotely sensed images.* describes important remote sensing platforms - including Landsat, SPOT and NOAA * examines and illustrates many of the applications of remotely sensed images in various fields.
The volume of remotely sensed imagery continues to grow at an enormous rate due to the advances in sensor technology, and our capability for collecting and storing images has greatly outpaced our ability to analyze and retrieve information from the images. This motivates us to develop image information mining techniques, which is very much an interdisciplinary endeavor drawing upon expertise in image processing, databases, information retrieval, machine learning, and software design. This dissertation proposes and implements an extensive remote sensing image information mining (ReSIM) system prototype for mining useful information implicitly stored in remote sensing imagery. The system consists of three modules: image processing subsystem, database subsystem, and visualization and graphical user interface (GUI) subsystem. Land cover and land use (LCLU) information corresponding to spectral characteristics is identified by supervised classification based on support vector machines (SVM) with automatic model selection, while textural features that characterize spatial information are extracted using Gabor wavelet coefficients. Within LCLU categories, textural features are clustered using an optimized k-means clustering approach to acquire search efficient space. The clusters are stored in an object-oriented database (OODB) with associated images indexed in an image database (IDB). A k-nearest neighbor search is performed using a query-by-example (QBE) approach. Furthermore, an automatic parametric contour tracing algorithm and an O(n) time piecewise linear polygonal approximation (PLPA) algorithm are developed for shape information mining of interesting objects within the image. A fuzzy object-oriented database based on the fuzzy object-oriented data (FOOD) model is developed to handle the fuzziness and uncertainty. Three specific applications are presented: integrated land cover and texture pattern mining, shape information mining for change detection of lakes, and
Edvardsson, Johannes; Šimanauskienė, Rasa; Taminskas, Julius; Baužienė, Ieva; Stoffel, Markus
Over the past century an ongoing establishment of Scots pine (Pinus sylvestris L.), sometimes at accelerating rates, is noted at three studied Lithuanian peat bogs, namely Kerėplis, Rėkyva and Aukštumala, all representing different degrees of tree coverage and geographic settings. Present establishment rates seem to depend on tree density on the bog surface and are most significant at sparsely covered sites where about three-fourth of the trees have established since the mid-1990s, whereas the initial establishment in general was during the early to mid-19th century. Three methods were used to detect, compare and describe tree establishment: (1) tree counts in small plots, (2) dendrochronological dating of bog pine trees, and (3) interpretation of aerial photographs and historical maps of the study areas. In combination, the different approaches provide complimentary information but also weigh up each other's drawbacks. Tree counts in plots provided a reasonable overview of age class distributions and enabled capturing of the most recently established trees with ages less than 50 years. The dendrochronological analysis yielded accurate tree ages and a good temporal resolution of long-term changes. Tree establishment and spread interpreted from aerial photographs and historical maps provided a good overview of tree spread and total affected area. It also helped to verify the results obtained with the other methods and an upscaling of findings to the entire peat bogs. The ongoing spread of trees in predominantly undisturbed peat bogs is related to warmer and/or drier climatic conditions, and to a minor degree to land-use changes. Our results therefore provide valuable insights into vegetation changes in peat bogs, also with respect to bog response to ongoing and future climatic changes. Copyright © 2014 Elsevier B.V. All rights reserved.
Rudd, R. D.; Bowden, L. W.; Colwell, R. N.; Estes, J. E.
A selective bibliography is presented which cites 89 textbooks, monographs, and articles covering introductory and advanced remote sensing techniques, photointerpretation, photogrammetry, and image processing.
Advances in Remote Sensing Approaches for Hazard Mitigation and Natural Resource Protection in Pacific Latin America: A Workshop for Advanced Graduate Students, Post- Doctoral Researchers, and Junior Faculty
Gierke, J. S.; Rose, W. I.; Waite, G. P.; Palma, J. L.; Gross, E. L.
Though much of the developing world has the potential to gain significantly from remote sensing techniques in terms of public health and safety, they often lack resources for advancing the development and practice of remote sensing. All countries share a mutual interest in furthering remote sensing capabilities for natural hazard mitigation and resource development. With National Science Foundation support from the Partnerships in International Research and Education program, we are developing a new educational system of applied research and engineering for advancing collaborative linkages among agencies and institutions in Pacific Latin American countries (to date: Guatemala, El Salvador, Nicaragua, Costa Rica, Panama, and Ecuador) in the development of remote sensing tools for hazard mitigation and water resources management. The project aims to prepare students for careers in science and engineering through their efforts to solve suites of problems needing creative solutions: collaboration with foreign agencies; living abroad immersed in different cultures; and adapting their academic training to contend with potentially difficult field conditions and limited resources. The ultimate goal of integrating research with education is to encourage cross-disciplinary, creative, and critical thinking in problem solving and foster the ability to deal with uncertainty in analyzing problems and designing appropriate solutions. In addition to traditional approaches for graduate and undergraduate research, we have built new educational systems of applied research and engineering: (1) the Peace Corp/Master's International program in Natural Hazards which features a 2-year field assignment during service in the U.S. Peace Corps, (2) the Michigan Tech Enterprise program for undergraduates, which gives teams of students from different disciplines the opportunity to work for three years in a business-like setting to solve real-world problems, and (3) a unique university exchange
Yahya, N N; Hashim, M; Ahmad, S
Understanding the sea floor biodiversity requires spatial information that can be acquired from remote sensing satellite data. Species volume, spatial patterns and species coverage are some of the information that can be derived. Current approaches for mapping sea bottom type have evolved from field observation, visual interpretation from aerial photography, mapping from remote sensing satellite data along with field survey and hydrograhic chart. Remote sensing offers most versatile technique to map sea bottom type up to a certain scale. This paper reviews the technical characteristics of signal and light interference within marine features, space and remote sensing satellite. In addition, related image processing techniques that are applicable to remote sensing satellite data for sea bottom type digital mapping is also presented. The sea bottom type can be differentiated by classification method using appropriate spectral bands of satellite data. In order to verify the existence of particular sea bottom type, field observations need to be carried out with proper technique and equipment
Mitchell, Anthea L; Rosenqvist, Ake; Mora, Brice
Forest degradation is a global phenomenon and while being an important indicator and precursor to further forest loss, carbon emissions due to degradation should also be accounted for in national reporting within the frame of UN REDD+. At regional to country scales, methods have been progressively developed to detect and map forest degradation, with these based on multi-resolution optical, synthetic aperture radar (SAR) and/or LiDAR data. However, there is no one single method that can be applied to monitor forest degradation, largely due to the specific nature of the degradation type or process and the timeframe over which it is observed. The review assesses two main approaches to monitoring forest degradation: first, where detection is indicated by a change in canopy cover or proxies, and second, the quantification of loss (or gain) in above ground biomass (AGB). The discussion only considers degradation that has a visible impact on the forest canopy and is thus detectable by remote sensing. The first approach encompasses methods that characterise the type of degradation and track disturbance, detect gaps in, and fragmentation of, the forest canopy, and proxies that provide evidence of forestry activity. Progress in these topics has seen the extension of methods to higher resolution (both spatial and temporal) data to better capture the disturbance signal, distinguish degraded and intact forest, and monitor regrowth. Improvements in the reliability of mapping methods are anticipated by SAR-optical data fusion and use of very high resolution data. The second approach exploits EO sensors with known sensitivity to forest structure and biomass and discusses monitoring efforts using repeat LiDAR and SAR data. There has been progress in the capacity to discriminate forest age and growth stage using data fusion methods and LiDAR height metrics. Interferometric SAR and LiDAR have found new application in linking forest structure change to degradation in tropical forests
Full Text Available The calibration and validation of remote sensing land cover products are highly dependent on accurate field reference data, which are costly and practically challenging to collect. We describe an optical method for collection of field reference data that is a fast, cost-efficient, and robust alternative to field surveys and UAV imaging. A lightweight, waterproof, remote-controlled RGB camera (GoPro HERO4 Silver, GoPro Inc. was used to take wide-angle images from 3.1 to 4.5 m in altitude using an extendable monopod, as well as representative near-ground (< 1 m images to identify spectral and structural features that correspond to various land covers in present lighting conditions. A semi-automatic classification was made based on six surface types (graminoids, water, shrubs, dry moss, wet moss, and rock. The method enables collection of detailed field reference data, which is critical in many remote sensing applications, such as satellite-based wetland mapping. The method uses common non-expensive equipment, does not require special skills or training, and is facilitated by a step-by-step manual that is included in the Supplement. Over time a global ground cover database can be built that can be used as reference data for studies of non-forested wetlands from satellites such as Sentinel 1 and 2 (10 m pixel size.
New hydrological insights for the region: The results revealed that there is observable inter-annual variability in inundation extent in the Barotse Floodplain with prominent differences demonstrated in both the flood ascending/peak and receding period. For the period 2003–2013 the results indicated a rising trend in inundation extent with a Mann–Kendall Z statistic of 1.71 and increase in magnitude of 33.1 km2 at significance level alpha of 0.05. Strong correlations between inundation extent and water level and between inundation extent and discharge with correlation coefficients of determination of 0.86 and 0.89 respectively were observed. For the period 2000–2011 water level time series showed a rising trend with the Mann–Kendall Z statistic of 2.97 and increase in magnitude of 0.1 m at significance level alpha of 0.05. Overall, during the period 1952–2004 discharge in the floodplain showed a declining trend with Mann–Kendall Z statistics of −2.88 and −3.38 at the inlet and outlet of the floodplain respectively. By correlation inference, the overall inundation extent trend in the floodplain was in a downward movement. Rainfall and discharge variability, high evapotranspiration and the changes in the land cover-use in the catchment of the floodplain are largely the factors affecting the observed variability and trends in inundation extent in the floodplain. The presented remote sensing based approach significantly reduces the need for the expensive and time limiting traditional physical field based wetland inundation mapping methods that form a limitation for achieving progress in wetland monitoring especially in open and sparsely gauged floodplains such as the Barotse.
Lo, C. P.; Quattrochi, Dale A.
Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.
Abdelrahman Aly, Anwar; Mosa Al-Omran, Abdulrasoul; Shahwan Sallam, Abdulazeam; Al-Wabel, Mohammad Ibrahim; Shayaa Al-Shayaa, Mohammad
Vegetation cover (VC) change detection is essential for a better understanding of the interactions and interrelationships between humans and their ecosystem. Remote sensing (RS) technology is one of the most beneficial tools to study spatial and temporal changes of VC. A case study has been conducted in the agro-ecosystem (AE) of Al-Kharj, in the center of Saudi Arabia. Characteristics and dynamics of total VC changes during a period of 26 years (1987-2013) were investigated. A multi-temporal set of images was processed using Landsat images from Landsat4 TM 1987, Landsat7 ETM+2000, and Landsat8 to investigate the drivers responsible for the total VC pattern and changes, which are linked to both natural and social processes. The analyses of the three satellite images concluded that the surface area of the total VC increased by 107.4 % between 1987 and 2000 and decreased by 27.5 % between years 2000 and 2013. The field study, review of secondary data, and community problem diagnosis using the participatory rural appraisal (PRA) method suggested that the drivers for this change are the deterioration and salinization of both soil and water resources. Ground truth data indicated that the deteriorated soils in the eastern part of the Al-Kharj AE are frequently subjected to sand dune encroachment, while the southwestern part is frequently subjected to soil and groundwater salinization. The groundwater in the western part of the ecosystem is highly saline, with a salinity ≥ 6 dS m-1. The ecosystem management approach applied in this study can be used to alike AE worldwide.
Blackburn, George Alan
The dynamics of pigment concentrations are diagnostic of a range of plant physiological properties and processes. This paper appraises the developing technologies and analytical methods for quantifying pigments non-destructively and repeatedly across a range of spatial scales using hyperspectral remote sensing. Progress in deriving predictive relationships between various characteristics and transforms of hyperspectral reflectance data are evaluated and the roles of leaf and canopy radiative transfer models are reviewed. Requirements are identified for more extensive intercomparisons of different approaches and for further work on the strategies for interpreting canopy scale data. The paper examines the prospects for extending research to the wider range of pigments in addition to chlorophyll, testing emerging methods of hyperspectral analysis and exploring the fusion of hyperspectral and LIDAR remote sensing. In spite of these opportunities for further development and the refinement of techniques, current evidence of an expanding range of applications in the ecophysiological, environmental, agricultural, and forestry sciences highlights the growing value of hyperspectral remote sensing of plant pigments.
Moore, H.J.; Boyce, J.M.; Schaber, G.G.; Scott, D.H.
Remote sensing and measurements of the Moon from Apollo orbiting spacecraft and Earth form a basis for extrapolation of Apollo surface data to regions of the Moon where manned and unmanned spacecraft have not been and may be used to discover target regions for future lunar exploration which will produce the highest scientific yields. Orbital remote sensing and measurements discussed include (1) relative ages and inferred absolute ages, (2) gravity, (3) magnetism, (4) chemical composition, and (5) reflection of radar waves (bistatic). Earth-based remote sensing and measurements discussed include (1) reflection of sunlight, (2) reflection and scattering of radar waves, and (3) infrared eclipse temperatures. Photographs from the Apollo missions, Lunar Orbiters, and other sources provide a fundamental source of data on the geology and topography of the Moon and a basis for comparing, correlating, and testing the remote sensing and measurements. Relative ages obtained from crater statistics and then empirically correlated with absolute ages indicate that significant lunar volcanism continued to 2.5 b.y. (billion years) ago-some 600 m.y. (million years) after the youngest volcanic rocks sampled by Apollo-and that intensive bombardment of the Moon occurred in the interval of 3.84 to 3.9 b.y. ago. Estimated fluxes of crater-producing objects during the last 50 m.y. agree fairly well with fluxes measured by the Apollo passive seismic stations. Gravity measurements obtained by observing orbiting spacecraft reveal that mare basins have mass concentrations and that the volume of material ejected from the Orientale basin is near 2 to 5 million km 3 depending on whether there has or has not been isostatic compensation, little or none of which has occurred since 3.84 b.y. ago. Isostatic compensation may have occurred in some of the old large lunar basins, but more data are needed to prove it. Steady fields of remanent magnetism were detected by the Apollo 15 and 16 subsatellites
Summers, R. A.; Smith, W. L.; Short, N. M.
The nature of the U.S. energy problem is examined. Based upon the best available estimates, it appears that demand for OPEC oil will exceed OPEC productive capacity in the early to mid-eighties. The upward pressure on world oil prices resulting from this supply/demand gap could have serious international consequences, both financial and in terms of foreign policy implementation. National Energy Plan objectives in response to this situation are discussed. Major strategies for achieving these objectives include a conversion of industry and utilities from oil and gas to coal and other abundant fuels. Remote sensing from aircraft and spacecraft could make significant contributions to the solution of energy problems in a number of ways, related to exploration of energy-related resources, the efficiency and safety of exploitation procedures, power plant siting, environmental monitoring and assessment, and the transportation infrastructure.
Gkarlaouni, Charikleia; Andreani, Louis; Pennos, Chris; Gloaguen, Richard; Papadimitriou, Eleftheria; Kilias, Adamantios; Michail, Maria
In Greek mainland, active extensional deformation resulted in the development of numerous seismogenic E- to SE-trending basins. The Mygdonia graben located in central Macedonia produced major historical earthquakes and poses a serious threat to the neighbouring city of Thessaloniki. Our aim is to determine which active seismic sources have the potential to generate strong events. Active tectonics shape the landscape, control the evolution of the fluvial network and cause the occurrence of strong and frequent earthquakes generated by fault populations. Thus, our approach combined both seismology and remote-sensed geomorphology. Seismological investigation and more especially relocation analysis was performed for recent seismicity in the area (2000-2012). Low magnitude earthquakes not exceeding 4.8 constitute the seismicity pattern for this period. Accurately determined focal parameters indicate that seismicity is not only localized along major fault zones. Smaller faults seem also to be activated. Temporal and spatial investigation show that seismicity is clustered and seismic bursts often migrate to adjacent faults. The hypocentral distribution of precisely determined microearthquake foci reveals the existence of high-angle (> 60º) normal faults dipping both south and north. This is consistent with fault plane solutions of stronger earthquakes. The largest amount of earthquakes is generated along the NW-SE sub-basin bounded from "Assiros-Analipsi" and "Lagina" fault zone, as well as in "Sochos" fault in the north which dips with approximately 70º-80º to the south. All these structures played an important role in the seismotectonic evolution of the area. We used geomorphic indices in order to analyse the landscapes of the Mygdonia region. Geomorphic indices were derived from DEM and computed using MATLAB scripts. We classified the landscapes according to their erosional stages using hypsometric integral and surface roughness. Both indices suggest stronger erosion
Yiran, G. A. B.; Kusimi, J. M.; Kufogbe, S. K.
A greater percentage of Northern Ghana is under threat of land degradation and is negatively impacting on the well-being of the people owing to deforestation, increasing incidence of drought, indiscriminate bush burning and desertification. The problem is becoming severe with serious implications on the livelihoods of the people as the land is the major resource from which they eke their living. Reversing land degradation requires sustainable land use planning which should be based on detailed up-to-date information on landscape attributes. This information can be generated through remote sensing analytical studies. Therefore, an attempt has been made in this study to collect data for planning by employing remote sensing techniques and ground truthing. The analysis included satellite image classification and change detection between Landsat images captured in 1989, 1999 and 2006. The images were classified into the following classes: water bodies, close savannah woodland, open savannah woodland, grassland/unharvested farmland, exposed soil, burnt scars, and settlement. Change detection performed between the 1989 and 1999 and 1989 and 2006 showed that the environment is deteriorating. Land covers such as close savannah woodland, open savannah woodland and exposed soil diminished over the period whereas settlement and water bodies increased. The grassland/unharvested farmland showed high increases because the images were captured at the time that some farms were still crops or crop residue. Urbanization, land clearing for farming, over grazing, firewood fetching and bush burning were identified as some of the underlying forces of vegetal cover degradation. The socio-cultural beliefs and practices of the people also influenced land cover change as sacred groves as well as medicinal plants are preserved. Local knowledge is recognized and used in the area but it is not properly integrated with scientific knowledge for effective planning for sustainable land management
Korres, Wolfgang; Montzka, Carsten; Fiener, Peter; Wilken, Florian; Stadler, Anja; Waldhoff, Guido; Schneider, Karl
The ratio of leaf area to ground area (leaf area index, LAI) is an important state variable in ecosystem studies since it influences fluxes of matter and energy between the land surface and the atmosphere. As a basis for generating temporally continuous and spatially distributed datasets of LAI, the current study contributes an analysis of its spatial variability and spatial structure. Soil-vegetation-atmosphere fluxes of water, carbon and energy are nonlinearly related to LAI. Therefore, its spatial heterogeneity, i.e., the combination of spatial variability and structure, has an effect on simulations of these fluxes. To assess LAI spatial heterogeneity, we apply a Comprehensive Data Analysis Approach that combines data from remote sensing (5 m resolution) and simulation (150 m resolution) with field measurements and a detailed land use map. Test area is the arable land in the fertile loess plain of the Rur catchment on the Germany-Belgium-Netherlands border. LAI from remote sensing and simulation compares well with field measurements. Based on the simulation results, we describe characteristic crop-specific temporal patterns of LAI spatial variability. By means of these patterns, we explain the complex multimodal frequency distributions of LAI in the remote sensing data. In the test area, variability between agricultural fields is higher than within fields. Therefore, spatial resolutions less than the 5 m of the remote sensing scenes are sufficient to infer LAI spatial variability. Frequency distributions from the simulation agree better with the multimodal distributions from remote sensing than normal distributions do. The spatial structure of LAI in the test area is dominated by a short distance referring to field sizes. Longer distances that refer to soil and weather can only be derived from remote sensing data. Therefore, simulations alone are not sufficient to characterize LAI spatial structure. It can be concluded that a comprehensive picture of LAI spatial
This report summarizes the technical work accomplished under Project THEMIS, A Center for Remote Sensing at the University of Kansas during the...period 16 September 1967 through 15 September 1973. The highlights of the four major areas forming the remote sensing system are presented. A detailed description of the latest radar spectrometer results is presented.
This volume debuts the new scope of Remote Sensing, which was first defined as the analysis of data collected by sensors that were not in physical contact with the objects under investigation (using cameras, scanners, and radar systems operating from spaceborne or airborne platforms). A wider characterization is now possible: Remote Sensing can be any non-destructive approach to viewing the buried and nominally invisible evidence of past activity. Spaceborne and airborne sensors, now supplemented by laser scanning, are united using ground-based geophysical instruments and undersea remote sensing, as well as other non-invasive techniques such as surface collection or field-walking survey. Now, any method that enables observation of evidence on or beneath the surface of the earth, without impact on the surviving stratigraphy, is legitimately within the realm of Remote Sensing. The new interfaces and senses engaged in Remote Sensing appear throughout the book. On a philosophical level, this is about the landscap...
Tiner, Ralph W; Klemas, Victor V
Effectively Manage Wetland Resources Using the Best Available Remote Sensing Techniques Utilizing top scientists in the wetland classification and mapping field, Remote Sensing of Wetlands: Applications and Advances covers the rapidly changing landscape of wetlands and describes the latest advances in remote sensing that have taken place over the past 30 years for use in mapping wetlands. Factoring in the impact of climate change, as well as a growing demand on wetlands for agriculture, aquaculture, forestry, and development, this text considers the challenges that wetlands pose for remote sensing and provides a thorough introduction on the use of remotely sensed data for wetland detection. Taking advantage of the experiences of more than 50 contributing authors, the book describes a variety of techniques for mapping and classifying wetlands in a multitude of environments ranging from tropical to arctic wetlands including coral reefs and submerged aquatic vegetation. The authors discuss the advantages and di...
Full Text Available A great number of glacial lakes have appeared in many mountain regions across the world during the last half-century due to receding of glaciers and global warming. In the present study, glacial lake outburst flood (GLOF risk assessment has been carried out in the Teesta river basin located in the Sikkim state of India. First, the study focuses on accurate mapping of the glaciers and glacial lakes using multispectral satellite images of Landsat and Indian Remote Sensing satellites. For glacier mapping, normalized difference snow index (NDSI image and slope map of the area have been utilized. NDSI approach can identify glaciers covered with clean snow but debris-covered glaciers cannot be mapped using NDSI method alone. For the present study, slope map has been utilized along with the NDSI approach to delineate glaciers manually. Glacial lakes have been mapped by supervised maximum likelihood classification and normalized difference water index followed by manual editing afterwards using Google Earth images. Second, the first proper inventory of glacial lakes for Teesta basin has been compiled containing information of 143 glacial lakes. Third, analysis of these lakes has been carried out for identification of potentially dangerous lakes. Vulnerable lakes have been identified on the basis of parameters like surface area, position with respect to parent glacier, growth since 2009, slope, distance from the outlet of the basin, presence of supraglacial lakes, presence of other lakes in downstream, condition of moraine, condition of the terrain around them, etc. From these criterions, in total, 18 lakes have been identified as potentially dangerous glacial lakes. Out of these 18 lakes, further analysis has been carried out for the identification of the most vulnerable lake. Lake 140 comes out to be the most vulnerable for a GLOF event. Lastly, for this potentially dangerous lake, different dam break parameters have been generated using satellite data
Reliable, high-capacity communications in scattering media can be effectively established with some basic remote sensing techniques involving time reversal. I will formulate these problems and discuss the various mathematical approaches that can be used for analysis. It turns out that stochastic analysis plays an important role and, in some cases, gives very satisfactory results. One such result is the spectacular increase in communications capacity in a richly scattering environment. I will end with a discussion of applications and computational issues that arise in the realistic simulation of communication systems.
Hadjimitsis, Diofantos G.; Agapiou, Athos; Lysandrou, Vasilki; Themistocleous, Kyriacos; Cuca, Branka; Nisantzi, Argyro; Lasaponara, Rosa; Masini, Nicola; Krauss, Thomas; Cerra, Daniele; Gessner, Ursula; Schreier, Gunter
Remote sensing science is increasingly being used to support archaeological and cultural heritage research in various ways. Satellite sensors either passive or active are currently used in a systematic basis to detect buried archaeological remains and to systematic monitor tangible heritage. In addition, airborne and low altitude systems are being used for documentation purposes. Ground surveys using remote sensing tools such as spectroradiometers and ground penetrating radars can detect variations of vegetation and soil respectively, which are linked to the presence of underground archaeological features. Education activities and training of remote sensing archaeology to young people is characterized of highly importance. Specific remote sensing tools relevant for archaeological research can be developed including web tools, small libraries, interactive learning games etc. These tools can be then combined and aligned with archaeology and cultural heritage. This can be achieved by presenting historical and pre-historical records, excavated sites or even artifacts under a "remote sensing" approach. Using such non-form educational approach, the students can be involved, ask, read, and seek to learn more about remote sensing and of course to learn about history. The paper aims to present a modern didactical concept and some examples of practical implementation of remote sensing archaeology in secondary schools in Cyprus. The idea was built upon an ongoing project (ATHENA) focused on the sue of remote sensing for archaeological research in Cyprus. Through H2020 ATHENA project, the Remote Sensing Science and Geo-Environment Research Laboratory at the Cyprus University of Technology (CUT), with the support of the National Research Council of Italy (CNR) and the German Aerospace Centre (DLR) aims to enhance its performance in all these new technologies.
Rose, Robert A.; Byler, Dirck; Eastman, J. Ron; Fleishman, Erica; Geller, Gary; Goetz, Scott; Guild, Liane; Hamilton, Healy; Hansen, Matt; Headley, Rachel; Hewson, Jennifer; Horning, Ned; Kaplin, Beth A.; Laporte, Nadine; Leidner, Allison K.; Leimgruber, Peter; Morisette, Jeffrey T.; Musinsky, John; Pintea, Lilian; Prados, Ana; Radeloff, Volker C.; Rowen, Mary; Saatchi, Sassan; Schill, Steve; Tabor, Karyn; Turner, Woody; Vodacek, Anthony; Vogelmann, James; Wegmann, Martin; Wilkie, David; Wilson, Cara
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain-referral survey. We then used a workshop-based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real-time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing-derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to
Rose, Robert A; Byler, Dirck; Eastman, J Ron; Fleishman, Erica; Geller, Gary; Goetz, Scott; Guild, Liane; Hamilton, Healy; Hansen, Matt; Headley, Rachel; Hewson, Jennifer; Horning, Ned; Kaplin, Beth A; Laporte, Nadine; Leidner, Allison; Leimgruber, Peter; Morisette, Jeffrey; Musinsky, John; Pintea, Lilian; Prados, Ana; Radeloff, Volker C; Rowen, Mary; Saatchi, Sassan; Schill, Steve; Tabor, Karyn; Turner, Woody; Vodacek, Anthony; Vogelmann, James; Wegmann, Martin; Wilkie, David; Wilson, Cara
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners' use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain-referral survey. We then used a workshop-based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real-time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing-derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to
Estes, J. E.; Sailer, C. T. (Principal Investigator); Tinney, L. R.
The current status of artificial intelligence AI technology is discussed along with imagery data management, database interrogation, and decision making. Techniques adapted from the field of artificial intelligence (AI) have significant, wide ranging impacts upon computer-assisted remote sensing analysis. AI based techniques offer a powerful and fundamentally different approach to many remote sensing tasks. In addition to computer assisted analysis, AI techniques can also aid onboard spacecraft data processing and analysis and database access and query.
Deepak R. Mishra
Full Text Available The Special Issue (SI on “Remote Sensing in Coastal Environments” presents a wide range of articles focusing on a variety of remote sensing models and techniques to address coastal issues and processes ranging for wetlands and water quality to coral reefs and kelp habitats. The SI is comprised of twenty-one papers, covering a broad range of research topics that employ remote sensing imagery, models, and techniques to monitor water quality, vegetation, habitat suitability, and geomorphology in the coastal zone. This preface provides a brief summary of each article published in the SI.
Brown, Molly E.
Remote sensing data has had an important role in identifying and responding to inter-annual variations in the African environment during the past three decades. As a largely agricultural region with diverse but generally limited government capacity to acquire and distribute ground observations of rainfall, temperature and other parameters, remote sensing is sometimes the only reliable measure of crop growing conditions in Africa. Thus, developing and maintaining the technical and scientific capacity to analyze and utilize satellite remote sensing data in Africa is critical to augmenting the continent's local weather/climate observation networks as well as its agricultural and natural resource development and management. The report Review of Remote Sensing Needs and Applications in Africa' has as its central goal to recommend to the US Agency for International Development an appropriate approach to support sustainable remote sensing applications at African regional remote sensing centers. The report focuses on "RS applications" to refer to the acquisition, maintenance and archiving, dissemination, distribution, analysis, and interpretation of remote sensing data, as well as the integration of interpreted data with other spatial data products. The report focuses on three primary remote sensing centers: (1) The AGRHYMET Regional Center in Niamey, Niger, created in 1974, is a specialized institute of the Permanent Interstate Committee for Drought Control in the Sahel (CILSS), with particular specialization in science and techniques applied to agricultural development, rural development, and natural resource management. (2) The Regional Centre for Maiming of Resources for Development (RCMRD) in Nairobi, Kenya, established in 1975 under the auspices of the United Nations Economic Commission for Africa and the Organization of African Unity (now the African Union), is an intergovernmental organization, with 15 member states from eastern and southern Africa. (3) The
Full Text Available On the basis of the cluster validity function based on geometric probability in literature [1, 2], propose a cluster analysis method based on geometric probability to process large amount of data in rectangular area. The basic idea is top-down stepwise refinement, firstly categories then subcategories. On all clustering levels, use the cluster validity function based on geometric probability firstly, determine clusters and the gathering direction, then determine the center of clustering and the border of clusters. Through TM remote sensing image classification examples, compare with the supervision and unsupervised classification in ERDAS and the cluster analysis method based on geometric probability in two-dimensional square which is proposed in literature 2. Results show that the proposed method can significantly improve the classification accuracy.
Lakshmi, T.V.; Reddy, M.A.; Anjaneyulu, Y.
This paper illustrate the impact of industrialization on water quality in and around Nakkavagu Watershed, due to unplanted industrial development. The study area falls between 78 deg. 05' - 78 deg. 25'E. longitude and 17 deg. 25'-17 deg. 45'N latitude, the catchment area extends 734 sq. km in Medak district, Andhra Predesh, India. The study area lies in the Godavari Basin. Remote sensing and GIS techniques are used to map the spatial and temporal distribution of water quality with respect to land use / land cover (Lu /Lc) changes for a period of three decades. Spatial database consisting of drainage network and geomorphology and land use / land cover change detection maps (1970-2004) have been generated for the entire watershed using remote sensing satellite data. Attribute database consisting of (water quality analysis is carried out and corresponding water quality index is calculated on a five point scale: 0- 25 Excellent, 26 -50 Good, 51 -75 Poor, 76 -100 Very poor, and> 100 Unfit for Drinking. Integrated study to establish the impact of Lu / Lc on water quality is carried out using GIS Analysis. Maps showing Lu / Lc changes and corresponding spatial distribution of water quality index were generated for the years 1979, 1989,2004. The results indicate that the water quality index in the entire Nakkavagu watershed during 1979 is excellent and good and by 2004, the entire watershed is rated in to poor, very poor and unfit for drinking. Best environmental management plans were suggested for restoration of the Nakkavagu watershed. (author)
Full Text Available The partitioning of available energy between sensible heat and latent heat is important for precise water resources planning and management in the context of global climate change. Land surface temperature (LST is a key variable in energy balance process and remotely sensed LST is widely used for estimating surface heat fluxes at regional scale. However, the inequality between LST and aerodynamic surface temperature (Taero poses a great challenge for regional heat fluxes estimation in one-source energy balance models. To address this issue, we proposed a One-Source Model for Land (OSML to estimate regional surface heat fluxes without requirements for empirical extra resistance, roughness parameterization and wind velocity. The proposed OSML employs both conceptual VFC/LST trapezoid model and the electrical analog formula of sensible heat flux (H to analytically estimate the radiometric-convective resistance (rae via a quartic equation. To evaluate the performance of OSML, the model was applied to the Soil Moisture-Atmosphere Coupling Experiment (SMACEX in United States and the Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE in China, using remotely sensed retrievals as auxiliary data sets at regional scale. Validated against tower-based surface fluxes observations, the root mean square deviation (RMSD of H and latent heat flux (LE from OSML are 34.5 W/m2 and 46.5 W/m2 at SMACEX site and 50.1 W/m2 and 67.0 W/m2 at MUSOEXE site. The performance of OSML is very comparable to other published studies. In addition, the proposed OSML model demonstrates similar skills of predicting surface heat fluxes in comparison to SEBS (Surface Energy Balance System. Since OSML does not require specification of aerodynamic surface characteristics, roughness parameterization and meteorological conditions with high spatial variation such as wind speed, this proposed method shows high potential for routinely acquisition of latent heat flux estimation
El-Gafy, Mohamed Anwar
Transportation projects will have impact on the environment. The general environmental pollution and damage caused by roads is closely associated with the level of economic activity. Although Environmental Impact Assessments (EIAs) are dependent on geo-spatial information in order to make an assessment, there are no rules per se how to conduct an environmental assessment. Also, the particular objective of each assessment is dictated case-by-case, based on what information and analyses are required. The conventional way of Environmental Impact Assessment (EIA) study is a time consuming process because it has large number of dependent and independent variables which have to be taken into account, which also have different consequences. With the emergence of satellite remote sensing technology and Geographic Information Systems (GIS), this research presents a new framework for the analysis phase of the Environmental Impact Assessment (EIA) for transportation projects based on the integration between remote sensing technology, geographic information systems, and spatial modeling. By integrating the merits of the map overlay method and the matrix method, the framework analyzes comprehensively the environmental vulnerability around the road and its impact on the environment. This framework is expected to: (1) improve the quality of the decision making process, (2) be applied both to urban and inter-urban projects, regardless of transport mode, and (3) present the data and make the appropriate analysis to support the decision of the decision-makers and allow them to present these data to the public hearings in a simple manner. Case studies, transportation projects in the State of Florida, were analyzed to illustrate the use of the decision support framework and demonstrate its capabilities. This cohesive and integrated system will facilitate rational decisions through cost effective coordination of environmental information and data management that can be tailored to
Del Soldato, Matteo; Bianchini, Silvia; Nolesini, Teresa; Frodella, William; Casagli, Nicola
Multisystem remote sensing techniques were exploited to provide a comprehensive overview of Volterra (Italy) site stability with regards to its landscape, urban fabric and cultural heritage. Interferometric Synthetic Aperture Radar (InSAR) techniques allow precise measurements of Earth surface displacement, as well as the detection of building deformations on large urban areas. In the field of cultural heritage conservation Infrared thermography (IRT) provides surface temperature mapping and therefore detects various potential criticalities, such as moisture, seepage areas, cracks and structural anomalies. Between winter 2014 and spring 2015 the historical center and south-western sectors of Volterra (Tuscany region, central Italy) were affected by instability phenomena. The spatial distribution, typology and effect on the urban fabrics of the landslide phenomena were investigated by analyzing the geological and geomorphological settings, traditional geotechnical monitoring and advanced remote sensing data such as Persistent Scatterers Interferometry (PSI). The ground deformation rates and the maximum settlement values derived from SAR acquisitions of historical ENVISAT and recent COSMO-SkyMed sensors, in 2003-2009 and 2010-2015 respectively, were compared with background geological data, constructive features, in situ evidences and detailed field inspections in order to classify landslide-damaged buildings. In this way, the detected movements and their potential correspondences with recognized damages were investigated in order to perform an assessment of the built-up areas deformations and damages on Volterra. The IRT technique was applied in order to survey the surface temperature of the historical Volterra wall-enclosure, and allowed highlighting thermal anomalies on this cultural heritage element of the site. The obtained results permitted to better correlate the landslide effects of the recognized deformations in the urban fabric, in order to provide useful
Gålfalk, Magnus; Karlson, Martin; Crill, Patrick; Bousquet, Philippe; Bastviken, David
The calibration and validation of remote sensing land cover products are highly dependent on accurate field reference data, which are costly and practically challenging to collect. We describe an optical method for collection of field reference data that is a fast, cost-efficient, and robust alternative to field surveys and UAV imaging. A lightweight, waterproof, remote-controlled RGB camera (GoPro HERO4 Silver, GoPro Inc.) was used to take wide-angle images from 3.1 to 4.5 m in altitude using an extendable monopod, as well as representative near-ground (wetland mapping. The method uses common non-expensive equipment, does not require special skills or training, and is facilitated by a step-by-step manual that is included in the Supplement. Over time a global ground cover database can be built that can be used as reference data for studies of non-forested wetlands from satellites such as Sentinel 1 and 2 (10 m pixel size).
David J. Lary
Full Text Available Learning incorporates a broad range of complex procedures. Machine learning (ML is a subdivision of artificial intelligence based on the biological learning process. The ML approach deals with the design of algorithms to learn from machine readable data. ML covers main domains such as data mining, difficult-to-program applications, and software applications. It is a collection of a variety of algorithms (e.g. neural networks, support vector machines, self-organizing map, decision trees, random forests, case-based reasoning, genetic programming, etc. that can provide multivariate, nonlinear, nonparametric regression or classification. The modeling capabilities of the ML-based methods have resulted in their extensive applications in science and engineering. Herein, the role of ML as an effective approach for solving problems in geosciences and remote sensing will be highlighted. The unique features of some of the ML techniques will be outlined with a specific attention to genetic programming paradigm. Furthermore, nonparametric regression and classification illustrative examples are presented to demonstrate the efficiency of ML for tackling the geosciences and remote sensing problems.
Zhang, Z; Xu, W; Zhou, W; Zhang, L; Xiao, Y; Ouyang, Z; Ou, X
The increasing exploitation of Karst resources is leading to severe environmental impacts, as Karst frequently occurs in the most fragile and vulnerable environments. This paper presents a multi-criteria evaluation (MCE) approach in a spatial context to support Karst rocky desertification (KRD) assessment by integrating remote sensing data with GIS. The study area is located in Wenshan Prefecture, Yunnan Province, Southwest of China. Criteria and impact factors for KRD first were identified and weighted through pairwise comparison method. A GIS fuzzy set membership function was then used to generate gradient effects of each criterion, and a clustering method based on K-mean algorithms was used to classify KRD into several descending rank zones (or levels). Both ROC and error matrix assessments indicated that the MCE approach is better than the NDVI approach. In addition, we found it is useful to integrate the topographic and human disturbance factors into KRD mapping and assessment, compared with most of the previous KRD assessment studies mainly focused on developing vegetation or land cover information in karst regions by using remote sensing alone. Furthermore, the integrated MCE approach is robust, flexible, and easy to be implemented. It also explicitly includes the quantitative and qualitative information, for instance, opinions of decision makers and experts as well as characteristics of the landscape
Faundeen, John L.; Kelly, Francis P.; Holm, Thomas M.; Nolt, Jenna E.
The National Satellite Land Remote Sensing Data Archive (NSLRSDA) resides at the U.S. Geological Survey's (USGS) Earth Resources Observation and Science (EROS) Center. Through the Land Remote Sensing Policy Act of 1992, the U.S. Congress directed the Department of the Interior (DOI) to establish a permanent Government archive containing satellite remote sensing data of the Earth's land surface and to make this data easily accessible and readily available. This unique DOI/USGS archive provides a comprehensive, permanent, and impartial observational record of the planet's land surface obtained throughout more than five decades of satellite remote sensing. Satellite-derived data and information products are primary sources used to detect and understand changes such as deforestation, desertification, agricultural crop vigor, water quality, invasive plant species, and certain natural hazards such as flood extent and wildfire scars.
Including an introduction and historical overview of the field, this comprehensive synthesis of the major biophysical applications of satellite remote sensing includes in-depth discussion of satellite-sourced biophysical metrics such as leaf area index.
National Oceanic and Atmospheric Administration, Department of Commerce — The Remote Sensing Division is responsible for providing data to support the Coastal Mapping Program, Emergency Response efforts, and the Aeronautical Survey Program...
Jin, Shuanggen; Xie, Feiqin
This book presents the theory and methods of GNSS remote sensing as well as its applications in the atmosphere, oceans, land and hydrology. It contains detailed theory and study cases to help the reader put the material into practice.
Lackey, J.G.; Burson, Z.G.
The Department of Energy has established a program called Comprehensive, Integrated Remote Sensing (CIRS). The overall objective of the program is to provide a state-of-the-art data base of remotely sensed data for all users of such information at large DOE sites. The primary types of remote sensing provided, at present, consist of the following: large format aerial photography, video from aerial platforms, multispectral scanning, and airborne nuclear radiometric surveys. Implementation of the CIRS Program by EG and G Energy Measurements, Inc. began with field operations at the Savannah River Plant in 1982 and is continuing at that DOE site at a level of effort of about $1.5 m per year. Integrated remote sensing studies were subsequently extended to the West Valley Demonstration Project in this summer and fall of 1984. It is expected that the Program will eventually be extended to cover all large DOE sites on a continuing basis
Aircraft and satellite aerial photographs represent indispensible tools for environmental observation today. They contribute to a systematic inventory of important environmental parameters such as climate, vegetation or surface water. Their great importance lies in the continuous monitoring of large regions so that changes in environmental conditions are quickly detected. This book provides an overview of the capabilities of remote sensing in environmental monitoring and in the recognition of environmental problems as well as of the usefulness of remote sensing data for environmental planning. Also addressed is the role of remote sensing in the monitoring of natural hazards such as earthquakes and volcano eruptions as well as problems of remote sensing technology transfer to developing countries. (orig.) [de
Full Text Available industries. In this paper we introduce the results from a remote sensing campaign performed in September 2001 at night time. For the first time nocturnal light pollution was measured at high spatial and spectral resolution using two airborne hyperspectral sensors, namely the Multispectral Infrared and Visible Imaging Spectrometer (MIVIS and the Visible InfraRed Scanner (VIRS-200. These imagers, generally employed for day-time Earth remote sensing, were flown over the Tuscany coast (Italy on board of a Casa 212/200 airplane from an altitude of 1.5-2.0 km. We describe the experimental activities which preceded the remote sensing campaign, the optimization of sensor configuration, and the images as far acquired. The obtained results point out the novelty of the performed measurements and highlight the need to employ advanced remote sensing techniques as a spectroscopic tool for light pollution monitoring.
EI Raey, M.
Full text: Basic principles of remote sensing of environment are outlined emphasizing inherent physical and target properties leading to proper identification and classification. Basic processing techniques are discussed. Applications of remote sensing techniques in various aspects of environmental monitoring and assessment is surveyed with emphasis on aspects of main concern to developing communities such as planning, sea level impacts, mine detection and earthquake prediction are all outlined and discussed
Full Text Available Education in remote sensing and GIS is based on software utilization. The software needs to be installed in computer rooms with a certain number of licenses. The commercial software equipment is therefore financially demanding and not only for universities, but especially for students. Internet research brings a long list of free software of various capabilities. The paper shows a present state of GIS, image processing and remote sensing free software.
Ahmad, T.; Shah, A.
A set of operators of remote sensing applications have been proposed to fulfill most of the Functional Requirements (FR). These operators capture the functions of the applications, which can be considered as the services provided by the applications. In general, a good application meets maximum FR from user. In this paper, we have defined a remote sensing application by a set, having all images created at dissimilar time instances, and each image is categorized into set of different layers. (author)
Education in remote sensing and GIS is based on software utilization. The software needs to be installed in computer rooms with a certain number of licenses. The commercial software equipment is therefore financially demanding and not only for universities, but especially for students. Internet research brings a long list of free software of various capabilities. The paper shows a present state of GIS, image processing and remote sensing free software.
Delre, Antonio; Mønster, Jacob; Scheutz, Charlotte
The direct release of nitrous oxide (N2O) and methane (CH4) from wastewater treatment plants (WWTP) is important because it contributes to the global greenhouse gases (GHGs) release and strongly effects the WWTP carbon footprint. Biological nitrogen removal technologies could increase the direct emission of N2O (IPCC, 2006), while CH4 losses are of environmental, economic and safety concern. Currently, reporting of N2O and CH4 emissions from WWTPs are performed mainly using methods suggested by IPCC which are not site specific (IPCC, 2006). The dynamic tracer dispersion method (TDM), a ground based remote sensing approach implemented at DTU Environment, was demonstrated to be a novel and successful tool for full-scale CH4 and N2O quantification from WWTPs. The method combines a controlled release of tracer gas from the facility with concentration measurements downwind of the plant (Mønster et al., 2014; Yoshida et al., 2014). TDM in general is based on the assumption that a tracer gas released at an emission source, in this case a WWTP, disperses into the atmosphere in the same way as the GHG emitted from process units. Since the ratio of their concentrations remains constant along their atmospheric dispersion, the GHG emission rate can be calculated using the following expression when the tracer gas release rate is known: EGHG=Qtr*(CGHG/Ctr)*(MWGHG/MWtr) EGHG is the GHG emission in mass per time, Qtr is the tracer release in mass per time, CGHG and Ctr are the concentrations measured downwind in parts per billion subtracted of their background values and integrated over the whole plume, and MWGHG and MWtr are the molar weights of GHG and tracer gas respectively (Mønster et al. 2014). In this study, acetylene (C2H2) was used as tracer. Downwind plume concentrations were measured driving along transects with two cavity ring down spectrometers (Yoshida et al., 2014). TDM was successfully applied in different seasons at several Scandinavian WWTPs characterized by
I. Remote Sensing Basics A. The electromagnetic spectrum demonstrates what we can see both in the visible and beyond the visible part of the spectrum through the use of various types of sensors. B. Resolution refers to what a remote sensor can see and how often. 1. Sp...
Richards, John A
Remote Sensing Digital Image Analysis provides the non-specialist with a treatment of the quantitative analysis of satellite and aircraft derived remotely sensed data. Since the first edition of the book there have been significant developments in the algorithms used for the processing and analysis of remote sensing imagery; nevertheless many of the fundamentals have substantially remained the same. This new edition presents material that has retained value since those early days, along with new techniques that can be incorporated into an operational framework for the analysis of remote sensing data. The book is designed as a teaching text for the senior undergraduate and postgraduate student, and as a fundamental treatment for those engaged in research using digital image processing in remote sensing. The presentation level is for the mathematical non-specialist. Since the very great number of operational users of remote sensing come from the earth sciences communities, the text is pitched at a leve...
Full Text Available Automated detection of landscape patterns on Remote Sensing imagery has seen virtually little or no development in the archaeological domain, notwithstanding the fact that large portion of cultural landscapes worldwide are characterized by land engineering applications. The current extraordinary availability of remotely sensed images makes it now urgent to envision and develop automatic methods that can simplify their inspection and the extraction of relevant information from them, as the quantity of information is no longer manageable by traditional “human” visual interpretation. This paper expands on the development of automatic methods for the detection of target landscape features—represented by field system patterns—in very high spatial resolution images, within the framework of an archaeological project focused on the landscape engineering embedded in Roman cadasters. The targets of interest consist of a variety of similarly oriented objects of diverse nature (such as roads, drainage channels, etc. concurring to demark the current landscape organization, which reflects the one imposed by Romans over two millennia ago. The proposed workflow exploits the textural and shape properties of real-world elements forming the field patterns using multiscale analysis of dominant oriented response filters. Trials showed that this approach provides accurate localization of target linear objects and alignments signaled by a wide range of physical entities with very different characteristics.
Estes, J. E.; Star, J. L.
Remote sensing uses a wide variety of techniques and methods. Resulting data are analyzed by man and machine, using both analog and digital technology. The newest and most important initiatives in the U. S. civilian space program currently revolve around the space station complex, which includes the core station as well as co-orbiting and polar satellite platforms. This proposed suite of platforms and support systems offers a unique potential for facilitating long term, multidisciplinary scientific investigations on a truly global scale. Unlike previous generations of satellites, designed for relatively limited constituencies, the space station offers the potential to provide an integrated source of information which recognizes the scientific interest in investigating the dynamic coupling between the oceans, land surface, and atmosphere. Earth scientist already face problems that are truly global in extent. Problems such as the global carbon balance, regional deforestation, and desertification require new approaches, which combine multidisciplinary, multinational research teams, employing advanced technologies to produce a type, quantity, and quality of data not previously available. The challenge before the international scientific community is to continue to develop both the infrastructure and expertise to, on the one hand, develop the science and technology of remote sensing, while on the other hand, develop an integrated understanding of global life support systems, and work toward a quantiative science of the biosphere.
Parking is an integral part of the traffic system everywhere. Provision of parking facilities to meet peak of demands parking in cities of millions is always a real challenge for traffic and transport experts. Parking demand is a function of population and car ownership which is obtained from traffic statistics. Parking supply in an area is the number of legal parking stalls available in that area. The traditional treatment of the parking studies utilizes data collected either directly from on street counting and inquiries or indirectly from local and national traffic censuses. Both methods consume time, efforts, and funds. Alternatively, it is reasonable to make use of the eventually available data based on remotely sensed data which might be flown for other purposes. The objective of this work is to develop a new approach based on utilization of integration of remotely sensed data, field measurements, censuses and traffic records of the studied area for studying domestic parking problems in residential areas especially in informal areas. Expected outcomes from the research project establish a methodology to manage the issue and to find the reasons caused the shortage in domestics and the solutions to overcome this problems.
The theme of IGARSS'99, ``Remote Sensing of the System Earth--A Challenge for the 21st Century,'' shows how earth observation based on satellite remote sensing can significantly contribute to the future study of the environment and the changes it is undergoing, whether from natural causes or human activities. The wide range of topics offers an interdisciplinary approach and suggests integrated techniques and theory in remote sensing are essential for modeling and understanding the environment. Topics covered include: new instrumentation and future systems; high resolution SAR/InSAR; earth system science educational initiative; data fusion; radar sensing of ice sheets; image processing techniques; clouds and ice particles; internal waves; natural hazards and disaster monitoring; advanced passive and active sensors and sensor calibration; radar assessment of rain, oil spills and natural slicks; data standards and distribution; and vegetation monitoring using BRDF approaches.
Remote Sensing has started to institute a “Best Paper” award to recognize the most outstanding papers in the area of remote sensing techniques, design and applications published in Remote Sensing. We are pleased to announce the first “Remote Sensing Best Paper Award” for the year 2014.
A study of the role of remote sensing for geologic reconnaissance for tunnel-site selection was commenced. For this study, remote sensing was defined...conventional remote sensing . Future research directions are suggested, and the extension of remote sensing to include airborne passive microwave
Rosenqvist, Ake; Imhoff, Marc; Milne, Anthony; Dobson, Craig
The Kyoto Protocol to the United Nations Framework Convention on Climate Change contains quantified, legally binding commitments to limit or reduce greenhouse gas emissions to 1990 levels and allows carbon emissions to be balanced by carbon sinks represented by vegetation. The issue of using vegetation cover as an emission offset raises a debate about the adequacy of current remote sensing systems and data archives to both assess carbon stocks/sinks at 1990 levels, and monitor the current and future global status of those stocks. These concerns and the potential ratification of the Protocol among participating countries is stimulating policy debates and underscoring a need for the exchange of information between the international legal community and the remote sensing community. On October 20-22 1999, two working groups of the International Society for Photogrammetry and Remote Sensing (ISPRS) joined with the University of Michigan (Michigan, USA) to convene discussions on how remote sensing technology could contribute to the information requirements raised by implementation of, and compliance with, the Kyoto Protocol. The meeting originated as a joint effort between the Global Monitoring Working Group and the Radar Applications Working Group in Commission VII of the ISPRS, co-sponsored by the University of Michigan. Tile meeting was attended by representatives from national government agencies and international organizations and academic institutions. Some of the key themes addressed were: (1) legal aspects of transnational remote sensing in the context of the Kyoto Protocol; (2) a review of the current and future and remote sensing technologies that could be applied to the Kyoto Protocol; (3) identification of areas where additional research is needed in order to advance and align remote sensing technology with the requirements and expectations of the Protocol; and 94) the bureaucratic and research management approaches needed to align the remote sensing
Fingas, M.; Fruhwirth, M.; Gamble, L.
The most common form of remote sensing as applied to oil spills is aerial remote sensing. The technology of aerial remote sensing, mainly from aircraft, is reviewed along with aircraft-mounted remote sensors and aircraft modifications. The characteristics, advantages, and limitations of optical techniques, infrared and ultraviolet sensors, fluorosensors, microwave and radar sensors, and slick thickness sensors are discussed. Special attention is paid to remote sensing of oil under difficult circumstances, such as oil in water or oil on ice. An infrared camera is the first sensor recommended for oil spill work, as it is the cheapest and most applicable device, and is the only type of equipment that can be bought off-the-shelf. The second sensor recommended is an ultraviolet and visible-spectrum device. The laser fluorosensor offers the only potential for discriminating between oiled and un-oiled weeds or shoreline, and for positively identifying oil pollution on ice and in a variety of other situations. However, such an instrument is large and expensive. Radar, although low in priority for purchase, offers the only potential for large-area searches and foul-weather remote sensing. Most other sensors are experimental or do not offer good potential for oil detection or mapping. 48 refs., 8 tabs
Isaacson, Sivan; Schüttler, Tobias; Cohen-Zada, Aviv L.; Blumberg, Dan G.; Girwidz, Raimund; Maman, Shimrit
Remote sensing is defined as data acquisition of an object, deprived physical contact. Fundamentally, most remote sensing applications are referred to as the use of satellite- or aircraft-based sensor technologies to detect and classify objects mainly on Earth or other planets. In the last years there have been efforts to bring the important subject of remote sensing into schools, however, most of these attempts focused on geography disciplines - restricting to the applications of remote sensing and to a less extent the technique itself and the physics behind it. Optical remote sensing is based on physical principles and technical devices, which are very meaningful from a theoretical point of view as well as for "hands-on" teaching. Some main subjects are radiation, atom and molecular physics, spectroscopy, as well as optics and the semiconductor technology used in modern digital cameras. Thus two objectives were outlined for this project: 1) to investigate the possibilities of using remote sensing techniques in physics teaching, and 2) to identify its impact on pupil's interest in the field of natural sciences. This joint project of the DLR_School_Lab, Oberpfaffenhofen of the German Aerospace Center (DLR) and the Earth and Planetary Image Facility (EPIF) at BGU, was conducted in 2016. Thirty teenagers (ages 16-18) participated in the project and were exposed to the cutting edge methods of earth observation. The pupils on both sides participated in the project voluntarily, knowing that at least some of the project's work had to be done in their leisure time. The pupil's project started with a day at EPIF and DLR respectively, where the project task was explained to the participants and an introduction to remote sensing of vegetation was given. This was realized in lectures and in experimental workshops. During the following two months both groups took several measurements with modern optical remote sensing systems in their home region with a special focus on flora
This slide presentation reviews current NASA Earth Remote Sensing observations in specific reference to improving public health information in view of pollen sensing. While pollen sampling has instrumentation, there are limitations, such as lack of stations, and reporting lag time. Therefore it is desirable use remote sensing to act as early warning system for public health reasons. The use of Juniper Pollen was chosen to test the possibility of using MODIS data and a dust transport model, Dust REgional Atmospheric Model (DREAM) to act as an early warning system.
Kanniah, K D; Sheikhi, A; Kang, C S
Development of cities has led to various environmental problems as a consequence of non sustaibale town planning. One of the strategies to make cities a livable place and to achieve low levels of CO 2 emissions (low carbon cities or LCC) is the integration of the blue and green infrastructure into the development and planning of new urban areas. Iskandar Malaysia (IM) located in the southern part of Malaysia is a special economic zone that has major urban centres. The planning of these urban centres will incorporate LCC strategies to achieve a sustainable development. The role of green (plants) and blue bodies (lakes and rivers) in moderating temperature in IM have been investigated in the current study. A remotely sensed satellite imagery was used to calculate the vegetation density and land surface temperature (LST). The effect of lakes in cooling the surrounding temperature was also investigated. Results show that increasing vegetation density by 1% can decrease the LST by 0.09°C. As for the water bodies we found as the distance increased from the lake side the temperature also increased about 1.7°C and the reduction in air humidity is 9% as the distance increased to 100 meter away from the lake
The remote sensing of urban areas has received much attention from scientists conducting studies on measuring sprawl, congestion, pollution, poverty, and environmental encroachment. Yet much of the research is case and data-specific where results are greatly influenced by prevailing local conditions. There seems to be a lack of epistemological links between remote sensing and conventional theoretical urban geography; in other words, an oversight for the appreciation of how urban theory fuels urban change and how urban change is measured by remotely sensed data. This paper explores basic urban theories such as centrality, mobility, materiality, nature, public space, consumption, segregation and exclusion, and how they can be measured by remote sensing sources. In particular, the link between structure (tangible objects) and function (intangible or immaterial behavior) is addressed as the theory that supports the wellknow contrast between land cover and land use classification from remotely sensed data. The paper then couches these urban theories and contributions from urban remote sensing within two analytical fields. The first is the search for an "appropriate" spatial scale of analysis, which is conveniently divided between micro and macro urban remote sensing for measuring urban structure, understanding urban processes, and perhaps contributions to urban theory at a variety of scales of analysis. The second is on the existence of a temporal lag between materiality of urban objects and the planning process that approved their construction, specifically how time-dependence in urban structural-functional models produce temporal lags that alter the causal links between societal and political functional demands and structural ramifications.
Tesser, D.; Hoang, L.; McDonald, K. C.
Efforts to improve municipal water supply systems increasingly rely on an ability to elucidate variables that drive hydrologic dynamics within large watersheds. However, fundamental model variables such as precipitation, soil moisture, evapotranspiration, and soil freeze/thaw state remain difficult to measure empirically across large, heterogeneous watersheds. Satellite remote sensing presents a method to validate these spatially and temporally dynamic variables as well as better inform the watershed models that monitor the water supply for many of the planet's most populous urban centers. PALSAR 2 L-band, Sentinel 1 C-band, and SMAP L-band scenes covering the Cannonsville branch of the New York City (NYC) water supply watershed were obtained for the period of March 2015 - October 2017. The SAR data provides information on soil moisture, free/thaw state, seasonal surface inundation, and variable source areas within the study site. Integrating the remote sensing products with watershed model outputs and ground survey data improves the representation of related processes in the Soil and Water Assessment Tool (SWAT) utilized to monitor the NYC water supply. PALSAR 2 supports accurate mapping of the extent of variable source areas while Sentinel 1 presents a method to model the timing and magnitude of snowmelt runoff events. SMAP Active Radar soil moisture product directly validates SWAT outputs at the subbasin level. This blended approach verifies the distribution of soil wetness classes within the watershed that delineate Hydrologic Response Units (HRUs) in the modified SWAT-Hillslope. The research expands the ability to model the NYC water supply source beyond a subset of the watershed while also providing high resolution information across a larger spatial scale. The global availability of these remote sensing products provides a method to capture fundamental hydrology variables in regions where current modeling efforts and in situ data remain limited.
Zhang Wanliang; Liu Dechang
This paper has discussed the latest development of satellite remote sensing in sensor resolutions, satellite motion models, load forms, data processing and its application. The authors consider that sensor resolutions of satellite remote sensing have increased largely. Valid integration of multisensors is a new idea and technology of satellite remote sensing in the 21st century, and post-remote sensing application technology is the important part of deeply applying remote sensing information and has great practical significance. (authors)
Al-Wassai, Firouz Abdullah; Kalyankar, N. V.
Several remote sensing software packages are used to the explicit purpose of analyzing and visualizing remotely sensed data, with the developing of remote sensing sensor technologies from last ten years. Accord-ing to literature, the remote sensing is still the lack of software tools for effective information extraction from remote sensing data. So, this paper provides a state-of-art of multi-sensor image fusion technologies as well as review on the quality evaluation of the single image or f...
Full Text Available Remote sensing, the science of obtaining information via noncontact recording, has swept the fields of ecology, biodiversity and conservation (EBC. Several quality review papers have contributed to this field. However, these papers often discuss the issues from the standpoint of an ecologist or a biodiversity specialist. This review focuses on the spaceborne remote sensing of EBC from the perspective of remote sensing specialists, i.e., it is organized in the context of state-of-the-art remote sensing technology, including instruments and techniques. Herein, the instruments to be discussed consist of high spatial resolution, hyperspectral, thermal infrared, small-satellite constellation, and LIDAR sensors; and the techniques refer to image classification, vegetation index (VI, inversion algorithm, data fusion, and the integration of remote sensing (RS and geographic information system (GIS.
Wang, Kai; Franklin, Steven E; Guo, Xulin; Cattet, Marc
Remote sensing, the science of obtaining information via noncontact recording, has swept the fields of ecology, biodiversity and conservation (EBC). Several quality review papers have contributed to this field. However, these papers often discuss the issues from the standpoint of an ecologist or a biodiversity specialist. This review focuses on the spaceborne remote sensing of EBC from the perspective of remote sensing specialists, i.e., it is organized in the context of state-of-the-art remote sensing technology, including instruments and techniques. Herein, the instruments to be discussed consist of high spatial resolution, hyperspectral, thermal infrared, small-satellite constellation, and LIDAR sensors; and the techniques refer to image classification, vegetation index (VI), inversion algorithm, data fusion, and the integration of remote sensing (RS) and geographic information system (GIS).
M. A. Lazaridou
Full Text Available Earth and its environment are studied by different scientific disciplines as geosciences, science of engineering, social sciences, geography, etc. The study of the above, beyond pure scientific interest, is useful for the practical needs of man. Photogrammetry and Remote Sensing (defined by Statute II of ISPRS is the art, science, and technology of obtaining reliable information from non-contact imaging and other sensor systems about the Earth and its environment, and other physical objects and of processes through recording, measuring, analyzing and representation. Therefore, according to this definition, photogrammetry and remote sensing can support studies of the above disciplines for acquisition of geoinformation. This paper concerns basic concepts of geosciences (geomorphology, geology, hydrology etc, and the fundamentals of photogrammetry-remote sensing, in order to aid the understanding of the relationship between photogrammetry-remote sensing and geoinformation and also structure curriculum in a brief, concise and coherent way. This curriculum can represent an appropriate research and educational outline and help to disseminate knowledge in various directions and levels. It resulted from our research and educational experience in graduate and post-graduate level (post-graduate studies relative to the protection of environment and protection of monuments and historical centers in the Lab. of Photogrammetry – Remote Sensing in Civil Engineering Faculty of Aristotle University of Thessaloniki.
Sawayama, Shuhei; Nurdin, Nurjannah; Akbar AS, Muhammad; Sakamoto, Shingo X.; Komatsu, Teruhisa
Coral reef ecosystems worldwide are now being harmed by various stresses accompanying the degradation of fish habitats and thus knowledge of fish-habitat relationships is urgently required. Because conventional research methods were not practical for this purpose due to the lack of a geospatial perspective, we attempted to develop a research method integrating visual fish observation with a seabed habitat map and to expand knowledge to a two-dimensional scale. WorldView-2 satellite imagery of Spermonde Archipelago, Indonesia obtained in September 2012 was analyzed and classified into four typical substrates: live coral, dead coral, seagrass and sand. Overall classification accuracy of this map was 81.3% and considered precise enough for subsequent analyses. Three sub-areas (CC: continuous coral reef, BC: boundary of coral reef and FC: few live coral zone) around reef slopes were extracted from the map. Visual transect surveys for several fish species were conducted within each sub-area in June 2013. As a result, Mean density (Ind. / 300 m2) of Chaetodon octofasciatus, known as an obligate feeder of corals, was significantly higher at BC than at the others (p < 0.05), implying that this species' density is strongly influenced by spatial configuration of its habitat, like the "edge effect." This indicates that future conservation procedures for coral reef fishes should consider not only coral cover but also its spatial configuration. The present study also indicates that the introduction of a geospatial perspective derived from remote sensing has great potential to progress conventional ecological studies on coral reef fishes.
Shook, D.F.; Salzman, J.; Svehla, R.A.; Gedney, R.T.
Remote sensing has been applied in the past to the surveillance of Great Lakes water quality, but it has been only partially successful because of the completely empirical approach taken in relating the multispectral scanning data at visible and near-infrared wavelengths to water parameters. Any remote sensing approach using water color information must take into account (1) the existence of many different organic and inorganic species throughtout the Greak Lakes, (2) the occurrence of a mixture of species in most locations, and (3) spatial (inter- and interlake as well as vertical) variations in types and concentrations of species. The radiative transfer model provides a potential method for an orderly analysis of remote sensing data and a physical basis for developing quantitative algorithms. Predictions and field measurements of volume reflectances are presented which clearly show the advantage of using a radiative transfer model. Spectral absorptance and backscattering coefficients for two inorganic sediments are reported
Daniel A. Griffith
Full Text Available Virtually all remotely sensed data contain spatial autocorrelation, which impacts upon their statistical features of uncertainty through variance inflation, and the compounding of duplicate information. Estimating the nature and degree of this spatial autocorrelation, which is usually positive and very strong, has been hindered by computational intensity associated with the massive number of pixels in realistically-sized remotely-sensed images, a situation that more recently has changed. Recent advances in spatial statistical estimation theory support the extraction of information and the distilling of knowledge from remotely-sensed images in a way that accounts for latent spatial autocorrelation. This paper summarizes an effective methodological approach to achieve this end, illustrating results with a 2002 remotely sensed-image of the Florida Everglades, and simulation experiments. Specifically, uncertainty of spatial autocorrelation parameter in a spatial autoregressive model is modeled with a beta-beta mixture approach and is further investigated with three different sampling strategies: coterminous sampling, random sub-region sampling, and increasing domain sub-regions. The results suggest that uncertainty associated with remotely-sensed data should be cast in consideration of spatial autocorrelation. It emphasizes that one remaining challenge is to better quantify the spatial variability of spatial autocorrelation estimates across geographic landscapes.
Lazaridou, Maria A.; Karagianni, Aikaterini Ch.
The rapid technologic advances in the scientific areas of photogrammetry and remote sensing require continuous readjustments at the educational programs and their implementation. The teaching teamwork should deal with the challenge to offer the volume of the knowledge without preventing the understanding of principles and methods and also to introduce "new" knowledge (advances, trends) followed by evaluation and presentation of relevant applications. This is of particular importance for a Civil Engineering Faculty as this in Aristotle University of Thessaloniki, as the framework of Photogrammetry and Remote Sensing is closely connected with applications in the four educational Divisions of the Faculty. This paper refers to the above and includes subjects of organizing the courses in photogrammetry and remote sensing in the Civil Engineering Faculty of Aristotle University of Thessaloniki. A scheme of the general curriculum as well the teaching aims and methods are also presented.
Full Text Available Triggered by earthquakes, rainfall, or anthropogenic activities, landslides represent widespread and problematic geohazards worldwide. In recent years, multiple remote sensing techniques, including synthetic aperture radar, optical, and light detection and ranging measurements from spaceborne, airborne, and ground-based platforms, have been widely applied for the analysis of landslide processes. Current techniques include landslide detection, inventory mapping, surface deformation monitoring, trigger factor analysis and mechanism inversion. In addition, landslide susceptibility modelling, hazard assessment, and risk evaluation can be further analyzed using a synergic fusion of multiple remote sensing data and other factors affecting landslides. We summarize the 19 articles collected in this special issue of Remote Sensing of Landslide, in the terms of data, methods and applications used in the papers.
Srivastava, Prashant K; Gupta, Manika; Islam, Tanvir
Remote Sensing Applications in Environmental Research is the basis for advanced Earth Observation (EO) datasets used in environmental monitoring and research. Now that there are a number of satellites in orbit, EO has become imperative in today's sciences, weather and natural disaster prediction. This highly interdisciplinary reference work brings together diverse studies on remote sensing and GIS, from a theoretical background to its applications, represented through various case studies and the findings of new models. The book offers a comprehensive range of contributions by well-known scientists from around the world and opens a new window for students in presenting interdisciplinary and methodological resources on the latest research. It explores various key aspects and offers state-of-the-art research in a simplified form, describing remote sensing and GIS studies for those who are new to the field, as well as for established researchers.
Crosson, William L.; Laymon, Charles A.; Inguva, Ramarao; Schamschula, Marius; Caulfield, John
' soil moisture under such conditions and even more difficult to apply such a value. Because of the non-linear relationships between near-surface soil moisture and other variables of interest, such as surface energy fluxes and runoff, mean soil moisture has little applicability at such large scales. It is for these reasons that the use of remote sensing in conjunction with a hydrologic model appears to be of benefit in capturing the complete spatial and temporal structure of soil moisture. This paper is Part I of a four-part series describing a method for intermittently assimilating remotely-sensed soil moisture information to improve performance of a distributed land surface hydrology model. The method, summarized in section II, involves the following components, each of which is detailed in the indicated section of the paper or subsequent papers in this series: Forward radiative transfer model methods (section II and Part IV); Use of a Kalman filter to assimilate remotely-sensed soil moisture estimates with the model profile (section II and Part IV); Application of a soil hydrology model to capture the continuous evolution of the soil moisture profile within and below the root zone (section III); Statistical aggregation techniques (section IV and Part II); Disaggregation techniques using a neural network approach (section IV and Part III); and Maximum likelihood and Bayesian algorithms for inversely solving for the soil moisture profile in the upper few cm (Part IV).
Canty, Morton J.; Nielsen, Allan Aasbjerg; Schlittenhardt, Jörg
change is a commonplace application in remote sensing, the detection of anthropogenic changes associated with nuclear activities, whether declared or clandestine, presents a difficult challenge. It is necessary to discriminate subtle, often weak signals of interest on a background of irrelevant...... in multispectral, bitemporal image data: New approaches to change detection studies, Remote Sens. Environ. 64(1), 1998, pp. 1--19. Nielsen, A. A., Iteratively re-weighted multivariate alteration detection in multi- and hyperspectral data, to be published....
Mitchell, Jessica J.; Glenn, Nancy F.; Sankey, Temuulen T.; Derryberry, DeWayne R.; Germino, Matthew J.
This paper presents a combination of techniques suitable for remotely sensing foliar Nitrogen (N) in semiarid shrublands – a capability that would significantly improve our limited understanding of vegetation functionality in dryland ecosystems. The ability to estimate foliar N distributions across arid and semi-arid environments could help answer process-driven questions related to topics such as controls on canopy photosynthesis, the influence of N on carbon cycling behavior, nutrient pulse dynamics, and post-fire recovery. Our study determined that further exploration into estimating sagebrush canopy N concentrations from an airborne platform is warranted, despite remote sensing challenges inherent to open canopy systems. Hyperspectral data transformed using standard derivative analysis were capable of quantifying sagebrush canopy N concentrations using partial least squares (PLS) regression with an R2 value of 0.72 and an R2 predicted value of 0.42 (n = 35). Subsetting the dataset to minimize the influence of bare ground (n = 19) increased R2 to 0.95 (R2 predicted = 0.56). Ground-based estimates of canopy N using leaf mass per unit area measurements (LMA) yielded consistently better model fits than ground-based estimates of canopy N using cover and height measurements. The LMA approach is likely a method that could be extended to other semiarid shrublands. Overall, the results of this study are encouraging for future landscape scale N estimates and represent an important step in addressing the confounding influence of bare ground, which we found to be a major influence on predictions of sagebrush canopy N from an airborne platform.
Beginning in 2004, NASA has supported the development of an international network of ground-based remote sensing installations for the measurement of greenhouse gas columns. This collaboration has been successful and is currently used in both carbon cycle investigations and in the efforts to validate the GOSAT space-based column observations of CO2 and CH4. With the support of a grant, this research group has established a network of ground-based column observations that provide an essential link between the satellite observations of CO2, CO, and CH4 and the extensive global in situ surface network. The Total Carbon Column Observing Network (TCCON) was established in 2004. At the time of this report seven sites, employing modern instrumentation, were operational or were expected to be shortly. TCCON is expected to expand. In addition to providing the most direct means of tying the in situ and remote sensing data sets together, TCCON provides a means of testing the retrieval algorithms of SCIAMACHY and GOSAT over the broadest variation in atmospheric state. TCCON provides a critically maintained and long timescale record for identification of temporal drift and spatial bias in the calibration of the space-based sensors. Finally, the global observations from TCCON are improving our understanding of how to use column observations to provide robust estimates of surface exchange of C02 and CH4 in advance of the launch of OCO and GOSAT. TCCON data are being used to better understand the impact of both regional fluxes and long-range transport on gradients in the C02 column. Such knowledge is essential for identifying the tools required to best use the space-based observations. The technical approach and methodology of retrieving greenhouse gas columns from near-IR solar spectra, data quality and process control are described. Additionally, the impact of and relevance to NASA of TCCON and satellite validation and carbon science are addressed.
Meier, G.A.; Brown, Jesslyn F.
Remote sensing of land-surface phenology is an important method for studying the patterns of plant and animal growth cycles. Phenological events are sensitive to climate variation; therefore phenology data provide important baseline information documenting trends in ecology and detecting the impacts of climate change on multiple scales. The USGS Remote sensing of land surface phenology program produces annually, nine phenology indicator variables at 250 m and 1,000 m resolution for the contiguous U.S. The 12 year archive is available at http://phenology.cr.usgs.gov/index.php.
This book provides a comprehensive overview of the state of the art in the field of thermal infrared remote sensing. Temperature is one of the most important physical environmental variables monitored by earth observing remote sensing systems. Temperature ranges define the boundaries of habitats on our planet. Thermal hazards endanger our resources and well-being. In this book renowned international experts have contributed chapters on currently available thermal sensors as well as innovative plans for future missions. Further chapters discuss the underlying physics and image processing techni
Hasager, Charlotte Bay
the uncertainty on the model results on the offshore wind resource, it is necessary to compare model results with observations. Observations from ground-based wind lidar and satellite remote sensing are the two main technologies that can provide new types of offshore wind data at relatively low cost....... The advantages of microwave satellite remote sensing are 1) horizontal spatial coverage, 2) long data archives and 3) high spatial detail both in the coastal zone and of far-field wind farm wake. Passive microwave ocean wind speed data are available since 1987 with up to 6 observations per day with near...
Bandini, Filippo; Garcia, Monica; Bauer-Gottwein, Peter
compared to other technologies: compared to field based techniques, remote sensing with UAVs is a non-destructive technique, less time consuming, ensures a reduced time between acquisition and interpretation of data and gives the possibility to access remote and unsafe areas. Compared to full...... will be able to record the spectral signatures of water and land surfaces with a pixel resolution of around 15 cm, whereas the thermal camera will sense water and land surface temperature with a resolution of 40 cm. Post-processing of data from the thermal camera will allow retrieving vegetation and soil...
Chen, H S
Space Remote Sensing Systems: An Introduction discusses the space remote sensing system, which is a modern high-technology field developed from earth sciences, engineering, and space systems technology for environmental protection, resource monitoring, climate prediction, weather forecasting, ocean measurement, and many other applications. This book consists of 10 chapters. Chapter 1 describes the science of the atmosphere and the earth's surface. Chapter 2 discusses spaceborne radiation collector systems, while Chapter 3 focuses on space detector and CCD systems. The passive space optical rad
Brown, R. L. (Principal Investigator)
The author has identified the following significant results. A limited study was conducted to determine the applicability of remote sensing for evaluating water quality conditions in the San Francisco Bay and delta. Considerable supporting data were available for the study area from other than overflight sources, but short-term temporal and spatial variability precluded their use. The study results were not sufficient to shed much light on the subject, but it did appear that, with the present state of the art in image analysis and the large amount of ground truth needed, remote sensing has only limited application in monitoring water quality.
Sallee, Jeff; Meier, Lesley R.
As humans, we perform remote sensing nearly all the time. This is because we acquire most of our information about our surroundings through the senses of sight and hearing. Whether viewed by the unenhanced eye or a military satellite, remote sensing is observing objects from a distance. With our current technology, remote sensing has become a part…
Jessup, A.; Holman, R. A.; Chickadel, C.; Elgar, S.; Farquharson, G.; Haller, M. C.; Kurapov, A. L.; Özkan-Haller, H. T.; Raubenheimer, B.; Thomson, J. M.
DARLA is 5-year collaborative project that couples state-of-the-art remote sensing and in situ measurements with advanced data assimilation (DA) modeling to (a) evaluate and improve remote sensing retrieval algorithms for environmental parameters, (b) determine the extent to which remote sensing data can be used in place of in situ data in models, and (c) infer bathymetry for littoral environments by combining remotely-sensed parameters and data assimilation models. The project uses microwave, electro-optical, and infrared techniques to characterize the littoral ocean with a focus on wave and current parameters required for DA modeling. In conjunction with the RIVET (River and Inlets) Project, extensive in situ measurements provide ground truth for both the remote sensing retrieval algorithms and the DA modeling. Our goal is to use remote sensing to constrain data assimilation models of wave and circulation dynamics in a tidal inlet and surrounding beaches. We seek to improve environmental parameter estimation via remote sensing fusion, determine the success of using remote sensing data to drive DA models, and produce a dynamically consistent representation of the wave, circulation, and bathymetry fields in complex environments. The objectives are to test the following three hypotheses: 1. Environmental parameter estimation using remote sensing techniques can be significantly improved by fusion of multiple sensor products. 2. Data assimilation models can be adequately constrained (i.e., forced or guided) with environmental parameters derived from remote sensing measurements. 3. Bathymetry on open beaches, river mouths, and at tidal inlets can be inferred from a combination of remotely-sensed parameters and data assimilation models. Our approach is to conduct a series of field experiments combining remote sensing and in situ measurements to investigate signature physics and to gather data for developing and testing DA models. A preliminary experiment conducted at
Van Aardt, JAN
Full Text Available relatively novel remote sensing approaches, namely imaging spectroscopy (hyperspectral remote sensing) and light detection and ranging (lidar), have the potential to alleviate this constraint. Specifically, the Carnegie Airborne Observatory, a state...
Rodríguez-González, Patricia María; Albuquerque, António; Martínez-Almarza, Miguel; Díaz-Delgado, Ricardo
Implementing long-term monitoring programs that effectively inform conservation plans is a top priority in environmental management. In floodplain forests, historical pressures interplay with the complex multiscale dynamics of fluvial systems and require integrative approaches to pinpoint drivers for their deterioration and ecosystem services loss. Combining a conceptual framework such as the Driver-Pressure-State-Impact-Response (DPSIR) with the development of valid biological indicators can contribute to the analysis of the driving forces and their effects on the ecosystem in order to formulate coordinated conservation measures. In the present study, we evaluate the initial results of a decade (2004-2014) of floodplain forest monitoring. We adopted the DPSIR framework to summarize the main drivers in land use and environmental change, analyzed the effects on biological indicators of foundation trees and compared the consistency of the main drivers and their effects at two spatial scales. The monitoring program was conducted in one of the largest and best preserved floodplain forests in SW Europe located within Doñana National Park (Spain) which is dominated by Salix atrocinerea and Fraxinus angustifolia. The program combined field (in situ) surveys on a network of permanent plots with several remote sensing sources. The accuracy obtained in spectral classifications allowed shifts in species cover across the whole forest to be detected and assessed. However, remote sensing did not reflect the ecological status of forest populations. The field survey revealed a general decline in Salix populations, especially in the first five years of sampling -a factor probably associated with a lag effect from past human impact on the hydrology of the catchment and recent extreme climatic episodes (drought). In spite of much reduced seed regeneration, a resprouting strategy allows long-lived Salix individuals to persist in complex spatial dynamics. This suggests the beginning
Ustinov, Eugene A.
An approach to formulation of inversion algorithms for remote sensing in the thermal spectral region in the case of a scattering planetary atmosphere, based on the adjoint equation of radiative transfer (Ustinov (JQSRT 68 (2001) 195; JQSRT 73 (2002) 29); referred to as Papers 1 and 2, respectively, in the main text), is applied to the general case of retrievals of atmospheric and surface parameters for the scattering atmosphere with nadir viewing geometry. Analytic expressions for corresponding weighting functions for atmospheric parameters and partial derivatives for surface parameters are derived. The case of pure atmospheric absorption with a scattering underlying surface is considered and convergence to results obtained for the non-scattering atmospheres (Ustinov (JQSRT 74 (2002) 683), referred to as Paper 3 in the main text) is demonstrated
+). An indirect remote sensing (RS) approach has been suggested to map the infrastructure used for degradation rather than the actual change in forest canopy cover. This offers a way to delineate intact forest land and to model and estimate emissions from forest degradation in the non‐intact forest land – thereby...
van Genderen, J.L.
A preliminary reconnaissance is being carried out to study the methods and procedures most useful for the detection of vegetation stress resulting from the various forms of environmental pollution, in the industrial area of Teesside, NE England, by means of a multiband remote sensing programme.
Li, Z.; Zhang, Y.; Hong, J.
Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF), whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.
Hasager, Charlotte Bay; Badger, Merete; Astrup, Poul
Satellite remote sensing of ocean surface winds are presented with focus on wind energy applications. The history on operational and research-based satellite ocean wind mapping is briefly described for passive microwave, scatterometer and synthetic aperture radar (SAR). Currently 6 GW installed...
Remote sensing technology has the potential to enhance the engagement of communities and managers in the implementation and performance of best management practices. This presentation will use examples from U.S. numeric criteria development and state water quality monitoring prog...
Full Text Available Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF, whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.
Su, Z.; Troch, P.A.A.
In order to quantify the rates of the exchanges of energy and matter among hydrosphere, biosphere and atmosphere, quantitative description of land surface processes by means of measurements at different scales are essential. Quantitative remote sensing plays an important role in this respect. The
Semiconductor injection lasers are required for implementing virtually all spaceborne remote sensing systems. Their main advantages are high reliability and efficiency, and their main roles are envisioned in pumping and injection locking of solid state lasers. In some shorter range applications they may even be utilized directly as the sources.
Remote sensing techniques hold considerable promise for the inventory and monitoring of natural resources on rangelands. A significant lack of information concerning basic spectral characteristics of range vegetation and soils has resulted in a lack of rangeland applications. The parameters of interest for range condition ...
Golberg, Mark; Polani, Sagi; Ozana, Nisan; Beiderman, Yevgeny; Garcia, Javier; Ruiz-Rivas Onses, Joaquin; Sanz Sabater, Martin; Shatsky, Max; Zalevsky, Zeev
In this paper we present the usage of photonic remote laser based device for sensing nano-vibrations for detection of muscle contraction and fatigue, eye movements and in-vivo estimation of glucose concentration. The same concept is also used to realize a remote optical stethoscope. The advantage of doing the measurements from a distance is in preventing passage of infections as in the case of optical stethoscope or in the capability to monitor e.g. sleep quality without disturbing the patient. The remote monitoring of glucose concentration in the blood stream and the capability to perform opto-myography for the Messer muscles (chewing) is very useful for nutrition and weight control. The optical configuration for sensing the nano-vibrations is based upon analyzing the statistics of the secondary speckle patterns reflected from various tissues along the body of the subjects. Experimental results present the preliminary capability of the proposed configuration for the above mentioned applications.
Falge, Eva; Brümmer, Christian
Park, South Africa, Setting up individual-based models to predict ecosystem dynamics under (post-) disturbance management, Monitoring vegetation amount and heterogeneity using remotely sensed images and aerial photography over several decades to examine time series of land cover change, and Investigations of livelihood strategies with focus on carbon balance components to develop sustainable management strategies for disturbed ecosystems and land use change. Despite recent advances, major innovations in understanding carbon cycle, greenhouse gases, air quality and measures of adaptation to and mitigation of climate change are still limited by the lack of global accessibility and comparability of relevant data (open data issues), long-term and sustainable interdisciplinary and trans-institutional research collaborations, and ongoing effective dialogues on multiple levels (policy, science, society).
Full Text Available Mangrove ecosystems dominate the coastal wetlands of tropical and subtropical regions throughout the world. They provide various ecological and economical ecosystem services contributing to coastal erosion protection, water filtration, provision of areas for fish and shrimp breeding, provision of building material and medicinal ingredients, and the attraction of tourists, amongst many other factors. At the same time, mangroves belong to the most threatened and vulnerable ecosystems worldwide and experienced a dramatic decline during the last half century. International programs, such as the Ramsar Convention on Wetlands or the Kyoto Protocol, underscore the importance of immediate protection measures and conservation activities to prevent the further loss of mangroves. In this context, remote sensing is the tool of choice to provide spatio-temporal information on mangrove ecosystem distribution, species differentiation, health status, and ongoing changes of mangrove populations. Such studies can be based on various sensors, ranging from aerial photography to high- and medium-resolution optical imagery and from hyperspectral data to active microwave (SAR data. Remote-sensing techniques have demonstrated a high potential to detect, identify, map, and monitor mangrove conditions and changes during the last two decades, which is reflected by the large number of scientific papers published on this topic. To our knowledge, a recent review paper on the remote sensing of mangroves does not exist, although mangrove ecosystems have become the focus of attention in the context of current climate change and discussions of the services provided by these ecosystems. Also, climate change-related remote-sensing studies in coastal zones have increased drastically in recent years. The aim of this review paper is to provide a comprehensive overview and sound summary of all of the work undertaken, addressing the variety of remotely sensed data applied for mangrove
We present two recent instrument technology developments at NASA, Fluid Lensing and MiDAR, and their application to remote sensing of Earth's aquatic systems. Fluid Lensing is the first remote sensing technology capable of imaging through ocean waves in 3D at sub-cm resolutions. MiDAR is a next-generation active hyperspectral remote sensing and optical communications instrument capable of active fluid lensing. Fluid Lensing has been used to provide 3D multispectral imagery of shallow marine systems from unmanned aerial vehicles (UAVs, or drones), including coral reefs in American Samoa and stromatolite reefs in Hamelin Pool, Western Australia. MiDAR is being deployed on aircraft and underwater remotely operated vehicles (ROVs) to enable a new method for remote sensing of living and nonliving structures in extreme environments. MiDAR images targets with high-intensity narrowband structured optical radiation to measure an objectâ€"TM"s non-linear spectral reflectance, image through fluid interfaces such as ocean waves with active fluid lensing, and simultaneously transmit high-bandwidth data. As an active instrument, MiDAR is capable of remotely sensing reflectance at the centimeter (cm) spatial scale with a signal-to-noise ratio (SNR) multiple orders of magnitude higher than passive airborne and spaceborne remote sensing systems with significantly reduced integration time. This allows for rapid video-frame-rate hyperspectral sensing into the far ultraviolet and VNIR wavelengths. Previously, MiDAR was developed into a TRL 2 laboratory instrument capable of imaging in thirty-two narrowband channels across the VNIR spectrum (400-950nm). Recently, MiDAR UV was raised to TRL4 and expanded to include five ultraviolet bands from 280-400nm, permitting UV remote sensing capabilities in UV A, B, and C bands and enabling mineral identification and stimulated fluorescence measurements of organic proteins and compounds, such as green fluorescent proteins in terrestrial and
Picard, R. H; Dewan, E. M; Winick, J. R; O'Neil, R. R
This report describes work carried out under the Air Force Research Laboratory's basic research task in optical remote-sensing signatures, entitled Optical / Infrared Signatures for Space-Based Remote Sensing...
Mapping water use and drought with satellite remote sensing. Martha C. Anderson, Bill Kustas, Feng Gao, Kate Semmens. USDA-Agricultural Research Service Hydrology and Remote Sensing Laboratory, Beltsville, MD. Chris Hain NOAA-NESDIS
Opportunities for Increasing Societal Value of Remote Sensing Data in South Africa's Strategic Development Priorities: A Review. ... Despite the enormous capital required to fund remote sensing initiatives, governments ... HOW TO USE AJOL.
Assessing the accuracy of remote sensing techniques in vegetation fractions estimation. ... This study aimed at exploring different remote sensing (RS) techniques for quantitatively measuring vegetation and bare soil ... HOW TO USE AJOL.
-Natal and MONDI Business Paper have recently embarked on a remote sensing cooperative. The primary focus of this cooperative is to explore the potential benefits associated with using remote sensing for forestry-related activities.
Bikhazi, Nicolas; Young, William F; Nguyen, Hung D
A technique for sensing a moving object within a physical environment using a MIMO communication link includes generating a channel matrix based upon channel state information of the MIMO communication link. The physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver. A spatial information variable is generated for the MIMO communication link based on the channel matrix. The spatial information variable includes spatial information about the moving object within the physical environment. A signature for the moving object is generated based on values of the spatial information variable accumulated over time. The moving object is identified based upon the signature.
Full Text Available This paper introduces the processing technology of high resolution remote sensing image, the specific making process of tourism map and different remote sensing data in the key application of tourism planning and so on. Remote sensing extracts agricultural tourism planning information, improving the scientificalness and operability of agricultural tourism planning. Therefore remote sensing image in the application of agricultural tourism planning will be the inevitable trend of tourism development.
Full Text Available coastal resources and anthropogenic infrastructure for a safer future. What is the role of remote sensing? The coastal zone connects terrestrial biophysical systems with marine systems. Some marine ecosystems cannot function without intact inland... for the development of sound integrated management solutions. To date, however, remote sensing applications usually focus on areas landward from the highwater line (?terrestrial? remote sensing), while ?marine? remote sensing does not pay attention to the shallow...
Shamin Roman; Alberto Gabriel Enrike; Uryngaliyeva Ayzhana; Semenov Aleksandr
The article considers the issues of optimizing the use of remote sensing data. Built a mathematical model to describe the economic effect of the use of remote sensing data. It is shown that this model is incorrect optimisation task. Given a numerical method of solving this problem. Also discusses how to optimize organizational structure by using genetic algorithm based on remote sensing. The methods considered allow the use of remote sensing data in an optimal way. The proposed mathematical m...
Pryse-Phillips, A.; Woolgar, R. [Hatch Ltd., St. John' s, NL (Canada); Puestow, T.; Warren, S. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada). C-Core; Rogers, K. [Nalcor Energy, St. John' s, NL (Canada); Khan, A. [Government of Newfoundland and Labrador, St. Johns, NL (Canada)
There has been an increase in the earth observation missions providing satellite imagery for operational monitoring applications. This technique has been found to be especially useful for the surveillance of large, remote areas, which is challenging to achieve in a cost-effective manner by conventional field-based or aerial means. This paper discussed the utility of satellite-based monitoring for different applications relevant to hydrology and water resources management. Emphasis was placed on the monitoring of river ice covers in near, real-time and water resources management. The paper first outlined river ice monitoring using remote sensing on the Lower Churchill River. The benefits of remote sensing over traditional survey methods for the dam industry was then outlined. Satellite image acquisition and interpretation for the Churchill River was then presented. Several images were offered. Watershed physiographic characterization using remote sensing was also described. It was concluded that satellite imagery proved to be a useful tool to develop physiographic characteristics when conducting rainfall-runoff modelling. 3 refs., 1 tab., 11 figs.
Steven G. Ackleson
Full Text Available An autonomous surface vehicle instrumented with optical and acoustical sensors was deployed in Kane'ohe Bay, HI, U.S.A., to provide high-resolution, in situ observations of coral reef reflectance with minimal human presence. The data represented a wide range in bottom type, water depth, and illumination and supported more thorough investigations of remote sensing methods for identifying and mapping shallow reef features. The in situ data were used to compute spectral bottom reflectance and remote sensing reflectance, Rrs,λ, as a function of water depth and benthic features. The signals were used to distinguish between live coral and uncolonized sediment within the depth range of the measurements (2.5–5 m. In situRrs, λ were found to compare well with remotely sensed measurements from an imaging spectrometer, the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS, deployed on an aircraft at high altitude. Cloud cover and in situ sensor orientation were found to have minimal impact on in situRrs, λ, suggesting that valid reflectance data may be collected using autonomous surveys even when atmospheric conditions are not favorable for remote sensing operations. The use of reflectance in the red and near infrared portions of the spectrum, expressed as the red edge height, REHλ, was investigated for detecting live aquatic vegetative biomass, including coral symbionts and turf algae. The REHλ signal from live coral was detected in Kane'ohe Bay to a depth of approximately 4 m with in situ measurements. A remote sensing algorithm based on the REHλ signal was defined and applied to AVIRIS imagery of the entire bay and was found to reveal areas of shallow, dense coral and algal cover. The peak wavelength of REHλ decreased with increasing water depth, indicating that a more complete examination of the red edge signal may potentially yield a remote sensing approach to simultaneously estimate vegetative biomass and bathymetry in shallow water.
Walker, A.S.; Robinove, Charles J.
Remote sensing techniques are valuable for locating, assessing, and monitoring desertification. Remotely sensed data provide a permanent record of the condition of the land in a format that allows changes in land features and condition to be measured. The annotated bibliography of 118 items discusses remote sensing methods that may be applied to desertification studies.
Veldkamp JG; Velde RJ van de; LBG
Dit rapport beschrijft de resultaten van het Beleidscommissie Remote Sensing (BCRS) project 'Verankering van toepassingen van terrestrische remote sensing bij RIVM'. Het had ten eerste tot doel te voldoen aan de voorwaarden, zoals gesteld in de inventarisatie van remote sensing als
Colwell, R. N.
A historical overview of the discovery and development of photography, related sciences, and remote sensing technology is presented. The role of education to date in the development of remote sensing is discussed. The probable future and potential of remote sensing and training is described.
Lin, Yu-Pin; Chu, Hone-Jay; Wang, Cheng-Long; Yu, Hsiao-Hsuan; Wang, Yung-Chieh
This study applies variogram analyses of normalized difference vegetation index (NDVI) images derived from SPOT HRV images obtained before and after the ChiChi earthquake in the Chenyulan watershed, Taiwan, as well as images after four large typhoons, to delineate the spatial patterns, spatial structures and spatial variability of landscapes caused by these large disturbances. The conditional Latin hypercube sampling approach was applied to select samples from multiple NDVI images. Kriging and sequential Gaussian simulation with sufficient samples were then used to generate maps of NDVI images. The variography of NDVI image results demonstrate that spatial patterns of disturbed landscapes were successfully delineated by variogram analysis in study areas. The high-magnitude Chi-Chi earthquake created spatial landscape variations in the study area. After the earthquake, the cumulative impacts of typhoons on landscape patterns depended on the magnitudes and paths of typhoons, but were not always evident in the spatiotemporal variability of landscapes in the study area. The statistics and spatial structures of multiple NDVI images were captured by 3,000 samples from 62,500 grids in the NDVI images. Kriging and sequential Gaussian simulation with the 3,000 samples effectively reproduced spatial patterns of NDVI images. However, the proposed approach, which integrates the conditional Latin hypercube sampling approach, variogram, kriging and sequential Gaussian simulation in remotely sensed images, efficiently monitors, samples and maps the effects of large chronological disturbances on spatial characteristics of landscape changes including spatial variability and heterogeneity.
Lin, Yu-Pin; Chu, Hone-Jay; Huang, Yu-Long; Tang, Chia-Hsi; Rouhani, Shahrokh
This study develops a stratified conditional Latin hypercube sampling (scLHS) approach for multiple, remotely sensed, normalized difference vegetation index (NDVI) images. The objective is to sample, monitor, and delineate spatiotemporal landscape changes, including spatial heterogeneity and variability, in a given area. The scLHS approach, which is based on the variance quadtree technique (VQT) and the conditional Latin hypercube sampling (cLHS) method, selects samples in order to delineate landscape changes from multiple NDVI images. The images are then mapped for calibration and validation by using sequential Gaussian simulation (SGS) with the scLHS selected samples. Spatial statistical results indicate that in terms of their statistical distribution, spatial distribution, and spatial variation, the statistics and variograms of the scLHS samples resemble those of multiple NDVI images more closely than those of cLHS and VQT samples. Moreover, the accuracy of simulated NDVI images based on SGS with scLHS samples is significantly better than that of simulated NDVI images based on SGS with cLHS samples and VQT samples, respectively. However, the proposed approach efficiently monitors the spatial characteristics of landscape changes, including the statistics, spatial variability, and heterogeneity of NDVI images. In addition, SGS with the scLHS samples effectively reproduces spatial patterns and landscape changes in multiple NDVI images.
ElFouly, A.; Salem, H.
Integration of Landsat-Thematic Mapper (TM), aero magnetic data, structural geology along with the known mineralization occurrences in the area are mainly the factors used to recognize favorable sites for structurally controlled mineralization at the northern part of the southeastern Desert of Egypt. Two knowledge-driven models were constructed based on a conceptual gold exploration model. The Density of Lineament Intersection (DLI) results from this study along with Dempster-Shafer (D-S) Belief approach show good results in delineating favorable mineralization areas. The basic assignment probability maps for the heat source, strong magnetism, hydrothermal alteration, geologic structure, and known mineralization occurrences in the area are the main D-S Belief approach recognition criteria component used for mineral exploration in the study area. The DLI method is maximizing the use of Landsat remote sensing data that could be used efficiently in the exploration for structurally controlled hydrothermal related mineralization. The DLI method results show higher resolution and accurate results for gold and base metals exploration. The high favorability areas by using the DLI method is 2196 Km 2 which are concise area than the D-S Belief approach for about 3976.5 Km 2 . These results are useful to be a strong base for planning accurate exploration program. The potential favorability maps of gold and base metals ore deposits from the northern part of the South Eastern Desert predicted the known areas of mineralization as well as identified high potential areas not known before with mineralization for future exploration
Fingas, Merv; Brown, Carl
Remote-sensing for oil spills is reviewed. The use of visible techniques is ubiquitous, however it gives only the same results as visual monitoring. Oil has no particular spectral features that would allow for identification among the many possible background interferences. Cameras are only useful to provide documentation. In daytime oil absorbs light and remits this as thermal energy at temperatures 3-8K above ambient, this is detectable by infrared (IR) cameras. Laser fluorosensors are useful instruments because of their unique capability to identify oil on backgrounds that include water, soil, weeds, ice and snow. They are the only sensor that can positively discriminate oil on most backgrounds. Radar detects oil on water by the fact that oil will dampen water-surface capillary waves under low to moderate wave/wind conditions. Radar offers the only potential for large area searches, day/night and foul weather remote sensing. Copyright © 2014 Elsevier Ltd. All rights reserved.
Faundeen, John L.; Longhenry, Ryan
The National Satellite Land Remote Sensing Data Archive is managed on behalf of the Secretary of the Interior by the U.S. Geological Survey’s Earth Resources Observation and Science Center. The Land Remote Sensing Policy Act of 1992 (51 U.S.C. §601) directed the U.S. Department of the Interior to establish a permanent global archive consisting of imagery over land areas obtained from satellites orbiting the Earth. The law also directed the U.S. Department of the Interior, delegated to the U.S. Geological Survey, to ensure proper storage and preservation of imagery, and timely access for all parties. Since 2008, these images have been available at no cost to the user.
Steinmaus, K.; Robert, B.; Berezin, S.A.
In June and July of 1997, the US Department of Energy, in cooperation with the Republic of Kazakhstan Ministry of Science - Academy of Science conducted a remote sensing mission to Kazakhstan. The mission was conducted as a technology demonstration under a Memorandum of Understanding between the United States Department of Energy and the Republic of Kazakhstan's Ministry of science - Academy of Science. The mission was performed using a US Navy P-3 Orion aircraft and imaging capabilities developed by the Department of Energy's Office of Non-proliferation and National Security. The imaging capabilities consisted of two imaging pods - a synthetic aperture radar (SAR) pod and a multi sensor imaging pod (MSI). Seven experiments were conducted to demonstrate how remote sensing can be used to support city planning, land cover mapping, mineral exploration, and non-proliferation monitoring. Results of the mission will be presented
Although the Federation does not sponsor or undertake surveillance and remote sensing research and development projects, it is a potential user of remote sensing equipment when responding to oil spills. Indeed, the Federation has already made use of suitably equipped aircraft on a number of occasions in Europe. Several countries in north west Europe, viz. France, Germany, Netherlands, Norway, Sweden and the U.K., operate aircraft fitted with broadly similar systems comprising side-looking airborne radar (SLAR), infra-red line scanners (IRLS) and ultra-violet line scanners (UVLS). These aircraft are used routinely for the detection of operational discharges of oil from ships in violation of the International Convention on the Prevention of Pollution from Ships 73/78 (MARPOL 73/78)
Chang, Sheng-Huei; Rubin, Tod D.
Traditional commercial remote sensing has focused on the geologic market, with primary focus on mineral identification and mapping in the visible through short-wave infrared spectral regions (0.4 to 2.4 microns). Commercial remote sensing users now demand airborne scanning capabilities spanning the entire wavelength range from ultraviolet through thermal infrared (0.3 to 12 microns). This spectral range enables detection, identification, and mapping of objects and liquids on the earth's surface and gases in the air. Applications requiring this range of wavelengths include detection and mapping of oil spills, soil and water contamination, stressed vegetation, and renewable and non-renewable natural resources, and also change detection, natural hazard mitigation, emergency response, agricultural management, and urban planning. GER has designed and built a configurable scanner that acquires high resolution images in 63 selected wave bands in this broad wavelength range.
Full Text Available Over the last several decades, remote sensing has emerged as an effective tool to monitor irrigated lands over a variety of climatic conditions and locations. The objective of this review, which summarizes the methods and the results of existing remote sensing studies, is to synthesize principle findings and assess the state of the art. We take a taxonomic approach to group studies based on location, scale, inputs, and methods, in an effort to categorize different approaches within a logical framework. We seek to evaluate the ability of remote sensing to provide synoptic and timely coverage of irrigated lands in several spectral regions. We also investigate the value of archived data that enable comparison of images through time. This overview of the studies to date indicates that remote sensing-based monitoring of irrigation is at an intermediate stage of development at local scales. For instance, there is overwhelming consensus on the efficacy of vegetation indices in identifying irrigated fields. Also, single date imagery, acquired at peak growing season, may suffice to identify irrigated lands, although to multi-date image data are necessary for improved classification and to distinguish different crop types. At local scales, the mapping of irrigated lands with remote sensing is also strongly affected by the timing of image acquisition and the number of images used. At the regional and global scales, on the other hand, remote sensing has not been fully operational, as methods that work in one place and time are not necessarily transferable to other locations and periods. Thus, at larger scales, more work is required to indentify the best spectral indices, best time periods, and best classification methods under different climatological and cultural environments. Existing studies at regional scales also establish the fact that both remote sensing and national statistical approaches require further refinement with a substantial investment of
Hantson, W.P.R.; Kooistra, L.; Slim, P.A.
Questions Does remote sensing improve classification of invasive woody species in dunes, useful for shrub management? Does additional height information and an object-based classifier increase woody species classification accuracy? Location The dunes of Vlieland, one of the Wadden Sea Islands, the
Aplicaciones Cientificas-C (SAC-C) satellites. CHAMP provided 8 years of radio oc- cultation data consisting of around 440,000 measurements from February...applications, various modifi- cations of terrestrial receivers are required, including hardware and software modifications to enhance surviv- ability in a...Dop- pler shifts. On the other hand, special hardware and software is required to support non-navigation remote sensing applications in space, such
Yertay, Alibek; Garrison, James L
Today, there are more than eight thousand satellites in space. Therefore, Radio Frequency (RF) signals broadcast from satellites can be accessed from almost every point on the earth. There will be number of satellites available at most points on earth with different frequency bands. These satellite signals can be used for remote sensing, therefore software that visualizes footprints of satellites and shows characteristics of every satellite available at any point would be useful in determinin...
remote sensing , cyclonic scale diagnostic studies and mesoscale numerical modeling and forecasting are summarized. Mechanisms involved in the release of potential instability are discussed and simulated quantitatively, giving particular attention to the convective formulation. The basic mesoscale model is documented including the equations, boundary condition, finite differences and initialization through an idealized frontal zone. Results of tests including a three dimensional test with real data, tests of convective/mesoscale interaction and tests with a detailed
McCarthy, Tim; Farrell, Ronan; Curtis, Andrew; Fotheringham, A. Stewart
Video imagery can be acquired from aerial, terrestrial and marine based platforms and has been exploited for a range of remote sensing applications over the past two decades. Examples include coastal surveys using aerial video, routecorridor infrastructures surveys using vehicle mounted video cameras, aerial surveys over forestry and agriculture, underwater habitat mapping and disaster management. Many of these video systems are based on interlaced, television standards such as North...
Mikeš, Stanislav; Haindl, Michal; Scarpa, G.; Gaetano, R.
Roč. 8, č. 5 (2015), s. 2240-2248 ISSN 1939-1404 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : benchmark * remote sensing segmentation * unsupervised segmentation * supervised segmentation Subject RIV: BD - Theory of Information Impact factor: 2.145, year: 2015 http://library.utia.cas.cz/separaty/2015/RO/haindl-0445995.pdf
Adams, John B.; Gillespie, Alan R.
Remote Sensing of Landscapes with Spectral Images describes how to process and interpret spectral images using physical models to bridge the gap between the engineering and theoretical sides of remote-sensing and the world that we encounter when we venture outdoors. The emphasis is on the practical use of images rather than on theory and mathematical derivations. Examples are drawn from a variety of landscapes and interpretations are tested against the reality seen on the ground. The reader is led through analysis of real images (using figures and explanations); the examples are chosen to illustrate important aspects of the analytic framework. This textbook will form a valuable reference for graduate students and professionals in a variety of disciplines including ecology, forestry, geology, geography, urban planning, archeology and civil engineering. It is supplemented by a web-site hosting digital color versions of figures in the book as well as ancillary images (www.cambridge.org/9780521662214). Presents a coherent view of practical remote sensing, leading from imaging and field work to the generation of useful thematic maps Explains how to apply physical models to help interpret spectral images Supplemented by a website hosting digital colour versions of figures in the book, as well as additional colour figures
Lynnes, Christopher; Leptoukh, Greg
This slide presentation reviews some of the issues in quality of remote sensing data. Data "quality" is used in several different contexts in remote sensing data, with quite different meanings. At the pixel level, quality typically refers to a quality control process exercised by the processing algorithm, not an explicit declaration of accuracy or precision. File level quality is usually a statistical summary of the pixel-level quality but is of doubtful use for scenes covering large areal extents. Quality at the dataset or product level, on the other hand, usually refers to how accurately the dataset is believed to represent the physical quantities it purports to measure. This assessment often bears but an indirect relationship at best to pixel level quality. In addition to ambiguity at different levels of granularity, ambiguity is endemic within levels. Pixel-level quality terms vary widely, as do recommendations for use of these flags. At the dataset/product level, quality for low-resolution gridded products is often extrapolated from validation campaigns using high spatial resolution swath data, a suspect practice at best. Making use of quality at all levels is complicated by the dependence on application needs. We will present examples of the various meanings of quality in remote sensing data and possible ways forward toward a more unified and usable quality framework.
This report concerns the feasibility of using remotely-sensed data for long-term monitoring of uranium tailings. Decommissioning of uranium mine tailings sites may require long-term monitoring to confirm that no unanticipated release of contaminants occurs. Traditional ground-based monitoring of specific criteria of concern would be a significant expense depending on the nature and frequency of the monitoring. The objective of this study was to evaluate whether available remote-sensing data and techniques were applicable to the long-term monitoring of tailings sites. This objective was met by evaluating to what extent the data and techniques could be used to identify and discriminate information useful for monitoring tailings sites. The cost associated with obtaining and interpreting this information was also evaluated. Satellite and aircraft remote-sensing-based activities were evaluated. A monitoring programme based on annual coverage of Landsat Thematic Mapper data is recommended. Immediately prior to and for several years after decommissioning of the tailings sites, airborne multispectral and thermal infrared surveys combined with field verification data are required in order to establish a baseline for the long-term satellite-based monitoring programme. More frequent airborne surveys may be required if rapidly changing phenomena require monitoring. The use of a geographic information system is recommended for the effective storage and manipulation of data accumulated over a number of years
Full Text Available The present paper aims at analyzing the potentialities of noninvasive remote sensing techniques used for detecting the conservation status of infrastructures. The applied remote sensing techniques are ground-based microwave radar interferometer and InfraRed Thermography (IRT to study a particular structure planned and made in the framework of the ISTIMES project (funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme. To exploit the effectiveness of the high-resolution remote sensing techniques applied we will use the high-frequency thermal camera to measure the structures oscillations by high-frequency analysis and ground-based microwave radar interferometer to measure the dynamic displacement of several points belonging to a large structure. The paper describes the preliminary research results and discusses on the future applicability and techniques developments for integrating high-frequency time series data of the thermal imagery and ground-based microwave radar interferometer data.
Draeger, William C.; Pettinger, Lawrence R.
Remote sensing may be defined as the science of imaging or measuring objects from a distance. More commonly, however, the term is used in reference to the acquisition and use of photographs, photo-like images, and other data acquired from aircraft and satellites. Thus, remote sensing includes the use of such diverse materials as photographs taken by hand from a light aircraft, conventional aerial photographs obtained with a precision mapping camera, satellite images acquired with sophisticated scanning devices, radar images, and magnetic and gravimetric data that may not even be in image form. Remotely sensed images may be color or black and white, can vary in scale from those that cover only a few hectares of the earth's surface to those that cover tens of thousands of square kilometers, and they may be interpreted visually or with the assistance of computer systems. This article attempts to describe several of the commonly available types of remotely sensed data, to discuss approaches to data analysis, and to demonstrate (with image examples) typical applications that might interest managers of parks and natural areas.
Tofani, Veronica; Agostini, Andrea; Segoni, Samuele; Catani, Filippo; Casagli, Nicola
results can be obtained combining remote sensing with ground based networks data and in field observations, as this can allow defining the deformation patterns of a landslide and its relationship with the triggering conditions . According to the research and working experience of the compilers, remote sensing is generally considered to have a medium effectiveness/reliability for landslide studies. Moreover this depends also on how remote sensing is used: an increase in the number of used remote sensing data type (aerial photos, satellite optical, satellite radar etc.), corresponds to a growth of the degree of effectiveness/reliability. In general the number of parameters detectable through remote sensing is linked to the number of techniques employed: an increase in the number of measured parameters is related to an increase in the number of the techniques used, both for monitoring and for detection/mapping. Many answers reported the possibility of detecting more than one parameters by only using radar technologies: this could be considered as an indicator of a better efficiency of radar with respect to optical techniques. The results of the questionnaire thus contribute to draw a sketch of the use of remote sensing in current landslide studies and show that remote sensing can be considered a powerful and well established instrument for landslides mapping, monitoring and hazard analysis and highlight that a wide range of available techniques and source data can be approached depending on the size and velocity of the investigated phenomena
Grecchi, Rosana Cristina; Beuchle, René; Shimabukuro, Yosio Edemir; Aragão, Luiz E. O. C.; Arai, Egidio; Simonetti, Dario; Achard, Frédéric
Forest cover disturbances due to processes such as logging and forest fires are a widespread issue especially in the tropics, and have heavily affected forest biomass and functioning in the Brazilian Amazon in the past decades. Satellite remote sensing has played a key role for assessing logging activities in this region; however, there are still remaining challenges regarding the quantification and monitoring of these processes affecting forested lands. In this study, we propose a new method for monitoring areas affected by selective logging in one of the hotspots of Mato Grosso state in the Brazilian Amazon, based on a combination of object-based and pixel-based classification approaches applied on remote sensing data. Logging intensity and changes over time are assessed within grid cells of 300 m × 300 m spatial resolution. Our method encompassed three main steps: (1) mapping forest/non-forest areas through an object-based classification approach applied to a temporal series of Landsat images during the period 2000-2015, (2) mapping yearly logging activities from soil fraction images on the same Landsat data series, and (3) integrating information from previous steps within a regular grid-cell of 300 m × 300 m in order to monitor disturbance intensities over this 15-years period. The overall accuracy of the baseline forest/non-forest mask (year 2000) and of the undisturbed vs disturbed forest (for selected years) were 93% and 84% respectively. Our results indicate that annual forest disturbance rates, mainly due to logging activities, were higher than annual deforestation rates during the whole period of study. The deforested areas correspond to circa 25% of the areas affected by forest disturbances. Deforestation rates were highest from 2001 to 2005 and then decreased considerably after 2006. In contrast, the annual forest disturbance rates show high temporal variability with a slow decrease over the 15-year period, resulting in a significant increase of the
Grecchi, Rosana Cristina; Beuchle, René; Shimabukuro, Yosio Edemir; Aragão, Luiz E O C; Arai, Egidio; Simonetti, Dario; Achard, Frédéric
Forest cover disturbances due to processes such as logging and forest fires are a widespread issue especially in the tropics, and have heavily affected forest biomass and functioning in the Brazilian Amazon in the past decades. Satellite remote sensing has played a key role for assessing logging activities in this region; however, there are still remaining challenges regarding the quantification and monitoring of these processes affecting forested lands. In this study, we propose a new method for monitoring areas affected by selective logging in one of the hotspots of Mato Grosso state in the Brazilian Amazon, based on a combination of object-based and pixel-based classification approaches applied on remote sensing data. Logging intensity and changes over time are assessed within grid cells of 300 m × 300 m spatial resolution. Our method encompassed three main steps: (1) mapping forest/non-forest areas through an object-based classification approach applied to a temporal series of Landsat images during the period 2000-2015, (2) mapping yearly logging activities from soil fraction images on the same Landsat data series, and (3) integrating information from previous steps within a regular grid-cell of 300 m × 300 m in order to monitor disturbance intensities over this 15-years period. The overall accuracy of the baseline forest/non-forest mask (year 2000) and of the undisturbed vs disturbed forest (for selected years) were 93% and 84% respectively. Our results indicate that annual forest disturbance rates, mainly due to logging activities, were higher than annual deforestation rates during the whole period of study. The deforested areas correspond to circa 25% of the areas affected by forest disturbances. Deforestation rates were highest from 2001 to 2005 and then decreased considerably after 2006. In contrast, the annual forest disturbance rates show high temporal variability with a slow decrease over the 15-year period, resulting in a significant increase
This presentation is part of the Independent Science Board of the State of California Delta Stewardship Council brown bag seminar series on the "How the Delta is Monitored", followed with a panel discussion. Various remote sensing approaches for aquatic vegetation will be reviewed. Key research and application issues with remote sensing monitoring in the Delta will be addressed.
Full Text Available Oceans/Seas are important components of Earth that are affected by global warming and climate change. Recent studies have indicated that the deeper oceans are responsible for climate variability by changing the Earth’s ecosystem; therefore, assessing them has become more important. Remote sensing can provide sea surface data at high spatial/temporal resolution and with large spatial coverage, which allows for remarkable discoveries in the ocean sciences. The deep layers of the ocean/sea, however, cannot be directly detected by satellite remote sensors. Therefore, researchers have examined the relationships between salinity, height, and temperature of the oceans/Seas to estimate their subsurface water temperature using dynamical models and model-based data assimilation (numerical based and statistical approaches, which simulate these parameters by employing remotely sensed data and in situ measurements. Due to the requirements of comprehensive perception and the importance of global warming in decision making and scientific studies, this review provides comprehensive information on the methods that are used to estimate ocean/sea subsurface water temperature from remotely and non-remotely sensed data. To clarify the subsurface processes, the challenges, limitations, and perspectives of the existing methods are also investigated.
Braverman, A. J.; Hobbs, J.
Remote sensing data sets produced by NASA and other space agencies are the result of complex algorithms that infer geophysical state from observed radiances using retrieval algorithms. The processing must keep up with the downlinked data flow, and this necessitates computational compromises that affect the accuracies of retrieved estimates. The algorithms are also limited by imperfect knowledge of physics and of ancillary inputs that are required. All of this contributes to uncertainties that are generally not rigorously quantified by stepping outside the assumptions that underlie the retrieval methodology. In this talk we discuss a practical framework for uncertainty quantification that can be applied to a variety of remote sensing retrieval algorithms. Ours is a statistical approach that uses Monte Carlo simulation to approximate the sampling distribution of the retrieved estimates. We will discuss the strengths and weaknesses of this approach, and provide a case-study example from the Orbiting Carbon Observatory 2 mission.
Full Text Available Robust risk assessment requires accurate flood intensity area mapping to allow for the identification of populations and elements at risk. However, available flood maps in West Africa lack spatial variability while global datasets have resolutions too coarse to be relevant for local scale risk assessment. Consequently, local disaster managers are forced to use traditional methods such as watermarks on buildings and media reports to identify flood hazard areas. In this study, remote sensing and Geographic Information System (GIS techniques were combined with hydrological and statistical models to delineate the spatial limits of flood hazard zones in selected communities in Ghana, Burkina Faso and Benin. The approach involves estimating peak runoff concentrations at different elevations and then applying statistical methods to develop a Flood Hazard Index (FHI. Results show that about half of the study areas fall into high intensity flood zones. Empirical validation using statistical confusion matrix and the principles of Participatory GIS show that flood hazard areas could be mapped at an accuracy ranging from 77% to 81%. This was supported with local expert knowledge which accurately classified 79% of communities deemed to be highly susceptible to flood hazard. The results will assist disaster managers to reduce the risk to flood disasters at the community level where risk outcomes are first materialized.
Cheng, Yufeng; Jin, Shuying; Wang, Mi; Zhu, Ying; Dong, Zhipeng
The linear array push broom imaging mode is widely used for high resolution optical satellites (HROS). Using double-cameras attached by a high-rigidity support along with push broom imaging is one method to enlarge the field of view while ensuring high resolution. High accuracy image mosaicking is the key factor of the geometrical quality of complete stitched satellite imagery. This paper proposes a high accuracy image mosaicking approach based on the big virtual camera (BVC) in the double-camera system on the GaoFen2 optical remote sensing satellite (GF2). A big virtual camera can be built according to the rigorous imaging model of a single camera; then, each single image strip obtained by each TDI-CCD detector can be re-projected to the virtual detector of the big virtual camera coordinate system using forward-projection and backward-projection to obtain the corresponding single virtual image. After an on-orbit calibration and relative orientation, the complete final virtual image can be obtained by stitching the single virtual images together based on their coordinate information on the big virtual detector image plane. The paper subtly uses the concept of the big virtual camera to obtain a stitched image and the corresponding high accuracy rational function model (RFM) for concurrent post processing. Experiments verified that the proposed method can achieve seamless mosaicking while maintaining the geometric accuracy.
Full Text Available Vegetation monitoring and mapping based on multi-temporal imagery has recently received much attention due to the plethora of medium-high spatial resolution satellites and the improved classification accuracies attained compared to uni-temporal approaches. Efficient image processing strategies are needed to exploit the phenological information present in temporal image sequences and to limit data redundancy and computational complexity. Within this framework, we implement the theory of Hidden Markov Models in crop classification, based on the time-series analysis of phenological states, inferred by a sequence of remote sensing observations. More specifically, we model the dynamics of vegetation over an agricultural area of Greece, characterized by spatio-temporal heterogeneity and small-sized fields, using RapidEye and Landsat ETM+ imagery. In addition, the classification performance of image sequences with variable spatial and temporal characteristics is evaluated and compared. The classification model considering one RapidEye and four pan-sharpened Landsat ETM+ images was found superior, resulting in a conditional kappa from 0.77 to 0.94 per class and an overall accuracy of 89.7%. The results highlight the potential of the method for operational crop mapping in Euro-Mediterranean areas and provide some hints for optimal image acquisition windows regarding major crop types in Greece.
Hickey, S. M.; Callow, N. J.; Phinn, S.; Lovelock, C. E.; Duarte, C. M.
Mangroves are integral to ecosystem services provided by the coastal zone, in particular carbon (C) sequestration and storage. Allometric relationships linking mangrove height to estimated biomass and C stocks have been developed from field sampling, while various forms of remote sensing has been used to map vegetation height and biomass. Here we combine both these approaches to investigate spatial patterns in living biomass of mangrove forests in a small area of mangrove in north-west Australia. This study used LiDAR data and Landsat 8 OLI (Operational Land Imager) with allometric equations to derive mangrove height, biomass, and C stock estimates. We estimated the study site, Mangrove Bay, a semi-arid site in north-western Australia, contained 70 Mg ha-1 biomass and 45 Mg C ha-1 organic C, with total stocks of 2417 Mg biomass and 778 Mg organic C. Using spatial statistics to identify the scale of clustering of mangrove pixels, we found that living biomass and C stock declined with increasing distance from hydrological features (creek entrance: 0-150 m; y = -0.00041x + 0.9613, R2 = 0.96; 150-770 m; y = -0.0008x + 1.6808, R2 = 0.73; lagoon: y = -0.0041x + 3.7943, R2 = 0.78). Our results illustrate a set pattern of living C distribution within the mangrove forest, and then highlight the role hydrologic features play in determining C stock distribution in the arid zone.
Novara, Agata; Pisciotta, Antonino; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Cerdà, Artemi; Gristina, Luciano
Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60cm depth. Soil was sampled every 10cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the pole height method which allowed mapping of the soil redistribution. The vigor of vegetation, expressed as Normalized Difference Vegetation Index (NDVI), derived from high-resolution satellite multispectral data, was compared with measured pruning weight. Results confirmed that soil erosion, sediment redistribution and SOC across the slope was strongly affected by topographic features, slope and curvature. The erosion rate was 16Mgha -1 y -1 since the time of planting (6years). SOC redistribution was strongly correlated with the detachment or deposition areas as highlighted by pole height measurements. The off-farm SOC loss over six years amounted to 1.2MgCha -1 . SUVA 254 values, which indicate hydrophobic material rich in aromatic constituents of WEOC, decreased significantly along the slope, demonstrating that WEOC in the detachment site is more stable in comparison to deposition sites. The plant vigor was strongly correlated with WEOC constituents. Results demonstrated that high resolution passive remote sensing data combined with soil and plant analyses can survey areas with contrasting SOC, soil fertility, soil erosion and plant vigor. This will allow monitoring of soil erosion and degradation risk areas and support decision-makers in developing measures for friendly
Le Bris, Anthony; Rosa, Philippe; Lerouxel, Astrid; Cognie, Bruno; Gernez, Pierre; Launeau, Patrick; Robin, Marc; Barillé, Laurent
The invasion of the wild oyster Crassostrea gigas along the western European Atlantic coast has generated changes in the structure and functioning of intertidal ecosystems. Considered as an invasive species and a trophic competitor of the cultivated conspecific oyster, it is now seen as a resource by oyster farmers following recurrent mass summer mortalities of oyster spat since 2008. Spatial distribution maps of wild oyster reefs are required by local authorities to help define management strategies. In this work, visible-near infrared (VNIR) hyperspectral and multispectral remote sensing was investigated to map two contrasted intertidal reef structures: clusters of vertical oysters building three-dimensional dense reefs in muddy areas and oysters growing horizontally creating large flat reefs in rocky areas. A spectral library, collected in situ for various conditions with an ASD spectroradiometer, was used to run Spectral Angle Mapper classifications on airborne data obtained with an HySpex sensor (160 spectral bands) and SPOT satellite HRG multispectral data (3 spectral bands). With HySpex spectral/spatial resolution, horizontal oysters in the rocky area were correctly classified but the detection was less efficient for vertical oysters in muddy areas. Poor results were obtained with the multispectral image and from spatially or spectrally degraded HySpex data, it was clear that the spectral resolution was more important than the spatial resolution. In fact, there was a systematic mud deposition on shells of vertical oyster reefs explaining the misclassification of 30% of pixels recognized as mud or microphytobenthos. Spatial distribution maps of oyster reefs were coupled with in situ biomass measurements to illustrate the interest of a remote sensing product to provide stock estimations of wild oyster reefs to be exploited by oyster producers. This work highlights the interest of developing remote sensing techniques for aquaculture applications in coastal
Full Text Available Looting of archaeological sites is illegal and considered a major anthropogenic threat for cultural heritage, entailing undesirable and irreversible damage at several levels, such as landscape disturbance, heritage destruction, and adverse social impact. In recent years, the employment of remote sensing technologies using ground-based and/or space-based sensors has assisted in dealing with this issue. Novel remote sensing techniques have tackled heritage destruction occurring in war-conflicted areas, as well as illicit archeological activity in vast areas of archaeological interest with limited surveillance. The damage performed by illegal activities, as well as the scarcity of reliable information are some of the major concerns that local stakeholders are facing today. This study discusses the potential use of remote sensing technologies based on the results obtained for the archaeological landscape of Ayios Mnason in Politiko village, located in Nicosia district, Cyprus. In this area, more than ten looted tombs have been recorded in the last decade, indicating small-scale, but still systematic, looting. The image analysis, including vegetation indices, fusion, automatic extraction after object-oriented classification, etc., was based on high-resolution WorldView-2 multispectral satellite imagery and RGB high-resolution aerial orthorectified images. Google Earth© images were also used to map and diachronically observe the site. The current research also discusses the potential for wider application of the presented methodology, acting as an early warning system, in an effort to establish a systematic monitoring tool for archaeological areas in Cyprus facing similar threats.
Jackson, T.J.; Schmugge, T.J.
Microwave remote sensing provides a unique capability for direct observation of soil moisture. Remote measurements from space afford the possibility of obtaining frequent, global sampling of soil moisture over a large fraction of the Earth's land surface. Microwave measurements have the benefit of being largely unaffected by cloud cover and variable surface solar illumination, but accurate soil moisture estimates are limited to regions that have either bare soil or low to moderate amounts of vegetation cover. A particular advantage of passive microwave sensors is that in the absence of significant vegetation cover soil moisture is the dominant effect on the received signal. The spatial resolutions of passive microwave soil moisture sensors currently considered for space operation are in the range 10–20 km. The most useful frequency range for soil moisture sensing is 1–5 GHz. System design considerations include optimum choice of frequencies, polarizations, and scanning configurations, based on trade-offs between requirements for high vegetation penetration capability, freedom from electromagnetic interference, manageable antenna size and complexity, and the requirement that a sufficient number of information channels be available to correct for perturbing geophysical effects. This paper outlines the basic principles of the passive microwave technique for soil moisture sensing, and reviews briefly the status of current retrieval methods. Particularly promising are methods for optimally assimilating passive microwave data into hydrologic models. Further studies are needed to investigate the effects on microwave observations of within-footprint spatial heterogeneity of vegetation cover and subsurface soil characteristics, and to assess the limitations imposed by heterogeneity on the retrievability of large-scale soil moisture information from remote observations
Remote sensing of vegetation function and traits has advanced significantly over the past half-century in the capacity to retrieve useful plant biochemical, physiological and structural quantities across a range of spatial and temporal scales. However, the translation of remote sensing signals into meaningful descriptors of vegetation function and traits is still associated with large uncertainties due to complex interactions between leaf, canopy, and atmospheric mediums, and significant challenges in the treatment of confounding factors in spectrum-trait relations. This editorial provides (1) a background on major advances in the remote sensing of vegetation, (2) a detailed timeline and description of relevant historical and planned satellite missions, and (3) an outline of remaining challenges, upcoming opportunities and key research objectives to be tackled. The introduction sets the stage for thirteen Special Issue papers here that focus on novel approaches for exploiting current and future advancements in remote sensor technologies. The described enhancements in spectral, spatial and temporal resolution and radiometric performance provide exciting opportunities to significantly advance the ability to accurately monitor and model the state and function of vegetation canopies at multiple scales on a timely basis.
McCullum, A. J. K.; Schmidt, C.; Blevins, B.; Weber, K.; Schnase, J. L.; Carroll, M.; Prados, A. I.
The utility of spatial data products and tools to assess risk and effectively manage wildfires has increased, highlighting the need for communicating information about these new capabilities to decision makers, resource managers, and community leaders. NASA's Applied Remote Sensing Training (ARSET) program works directly with agencies and policy makers to develop in-person and online training courses that teach end users how to access, visualize, and apply NASA Earth Science data in their profession. The expansion of ARSET into wildfire applications began in 2015 with a webinar and subsequent in-person training hosted in collaboration with Idaho State University's (ISU) GIS Training and Research Center (TReC). These trainings featured presentations from the USDA Forest Service's Remote Sensing Training and Applications Center, the Land Processes DAAC, Northwest Nazarene University, NASA Goddard Space Flight Center, and ISU's GIS TReC. The webinar focused on providing land managers, non-governmental organizations, and international management agencies with an overview of 1) remote sensing platforms for wildfire applications, 2) products for pre- and post-fire planning and assessment, 3) the use of terrain data, 4) new techniques and technologies such as Unmanned Aircraft Systems and the Soil Moisture Active Passive Mission (SMAP), and 5) the RECOVER Decision Support System. This training highlighted online tools that engage the wildfire community through collaborative monitoring and assessment efforts. Webinar attendance included 278 participants from 178 organizations in 42 countries and 33 US states. The majority of respondents (93%) from a post-webinar survey indicated they displayed improvement in their understanding of specific remote-sensing data products appropriate for their work needs. With collaborative efforts between federal, state, and local agencies and academic institutions, increased use of NASA Earth Observations may lead to improved near real
Siegal, B.S.; Welby, C.W.
Remote sensing techniques enhance the selection and evaluation process for nuclear power plant siting. The principal advantage is the synoptic view which improves recognition of linear features, possibly indicative of faults. The interpretation of such images, in conjunction with seismological studies, also permits delineation of seismo-tectonic provinces. In volcanic terrains, geomorphic-age boundaries can be delineated and volcanic centers identified, providing necessary guidance for field sampling and regional model derivation. The use of such techniques is considered for studies in the Philippines, Mexico, and Greece. 5 refs
Tinney, L.; Christel, L.; Clark, H.; Mackey, H.
The United States Department of Energy (USDOE) maintains a Remote Sensing Laboratory (RSL) to support nuclear related programs of the US Government. The mission of the organization includes both emergency response and routine environmental assessments of nuclear facilities. The unique suite of equipment used by RSL for multisensor surveys of nuclear facilities include gamma radiation sensors, mapping quality aerial cameras, video cameras, thermal imagers, and multispectral scanners. Results for RSL multisensor surveys that have been conducted at the Savannah River Site (SRS) located in South Carolina are presented
Bernabeu i Altayó, Gerard; Universitat Autònoma de Barcelona. Departament d'Arquitectura de Computadors i Sistemes Operatius
Remote sensing spatial, spectral, and temporal resolutions of images, acquired Les resolucions espacials, espectrals i temporals d'imatges de teledetecci ó, adquirides a una mida raonable, donen com a resultat imatges que es poden processar per a representar grans àrees de terreny amb un nivell de detall espacial que es Las resoluciones espaciales, espectrales y temporales de imágenes de teledetección, adquiridas a un tamaño razonable, dan como resultado imágenes que se pueden procesar ...
Handley, J F
The contribution of remote sensing to environmental management procedures at the sub-regional scale is examined in relation to the County Structure environmental management plan for Merseyside County, England. The various seasons, scales and emulsions used for aerial photography in the county are indicated, and results of aerial surveys of the distribution of derelict and despoiled land and of natural environments are presented and compared with ground surveys. The use of color infrared and panchromatic aerial photographs indicating areas of environmental stress and land use in the formulation, implementation and monitoring of environmental management activities is then discussed.
Unmanned systems and robotics technologies have become very popular recently owing to their ability to replace human beings in dangerous, tedious, or repetitious jobs. This book fill the gap in the field between research and real-world applications, providing scientists and engineers with essential information on how to design and employ networked unmanned vehicles for remote sensing and distributed control purposes. Target scenarios include environmental or agricultural applications such as river/reservoir surveillance, wind profiling measurement, and monitoring/control of chemical leaks.
Werdell, P. Jeremy; McKinna, Lachlan I. W.; Boss, Emmanuel; Ackleson, Steven G.; Craig, Susanne E.; Gregg, Watson W.; Lee, Zhongping; Maritorena, Stéphane; Roesler, Collin S.; Rousseaux, Cécile S.; Stramski, Dariusz; Sullivan, James M.; Twardowski, Michael S.; Tzortziou, Maria; Zhang, Xiaodong
Ocean color measured from satellites provides daily global, synoptic views of spectral water-leaving reflectances that can be used to generate estimates of marine inherent optical properties (IOPs). These reflectances, namely the ratio of spectral upwelled radiances to spectral downwelled irradiances, describe the light exiting a water mass that defines its color. IOPs are the spectral absorption and scattering characteristics of ocean water and its dissolved and particulate constituents. Because of their dependence on the concentration and composition of marine constituents, IOPs can be used to describe the contents of the upper ocean mixed layer. This information is critical to further our scientific understanding of biogeochemical oceanic processes, such as organic carbon production and export, phytoplankton dynamics, and responses to climatic disturbances. Given their importance, the international ocean color community has invested significant effort in improving the quality of satellite-derived IOP products, both regionally and globally. Recognizing the current influx of data products into the community and the need to improve current algorithms in anticipation of new satellite instruments (e.g., the global, hyperspectral spectroradiometer of the NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission), we present a synopsis of the current state of the art in the retrieval of these core optical properties. Contemporary approaches for obtaining IOPs from satellite ocean color are reviewed and, for clarity, separated based their inversion methodology or the type of IOPs sought. Summaries of known uncertainties associated with each approach are provided, as well as common performance metrics used to evaluate them. We discuss current knowledge gaps and make recommendations for future investment for upcoming missions whose instrument characteristics diverge sufficiently from heritage and existing sensors to warrant reassessing current approaches.
Muralidharan, Govindarajan; Britton, Charles L.; Pearce, James; Jagadish, Usha; Sikka, Vinod K.
A low-power shock sensing system includes at least one shock sensor physically coupled to a chemical storage tank to be monitored for impacts, and an RF transmitter which is in a low-power idle state in the absence of a triggering signal. The system includes interference circuitry including or activated by the shock sensor, wherein an output of the interface circuitry is coupled to an input of the RF transmitter. The interface circuitry triggers the RF transmitting with the triggering signal to transmit an alarm message to at least one remote location when the sensor senses a shock greater than a predetermined threshold. In one embodiment the shock sensor is a shock switch which provides an open and a closed state, the open state being a low power idle state.
Kiefer, R. W.
The content of typical basic and advanced remote sensing and image interpretation courses are described and typical remote sensing graduate programs of study in civil engineering and in interdisciplinary environmental remote sensing and water resources management programs are outlined. Ideally, graduate programs with an emphasis on remote sensing and image interpretation should be built around a core of five courses: (1) a basic course in fundamentals of remote sensing upon which the more specialized advanced remote sensing courses can build; (2) a course dealing with visual image interpretation; (3) a course dealing with quantitative (computer-based) image interpretation; (4) a basic photogrammetry course; and (5) a basic surveying course. These five courses comprise up to one-half of the course work required for the M.S. degree. The nature of other course work and thesis requirements vary greatly, depending on the department in which the degree is being awarded.
Balmer, M.L.; Lange, F.F.; Levi, C.G.
These proceedings contain papers presented at the Eighth Thematic Conference on Geologic Remote Sensing. This meeting was held April 29-May 2, 1991, in Denver, Colorado, USA. The conference was organized by the Environmental Research Institute of Michigan, in Cooperation with an international program committee composed primarily of geologic remote sensing specialists. The meeting was convened to discuss state-of-the-art exploration, engineering, and environmental applications of geologic remote sensing as well as research and development activities aimed at increasing the future capabilities of this technology. The presentations in these volumes address the following topics: Spectral Geology; U.S. and International Hydrocarbon Exploration; Radar and Thermal Infrared Remote Sensing; Engineering Geology and Hydrogeology; Minerals Exploration; Remote Sensing for Marine and Environmental Applications; Image Processing and Analysis; Geobotanical Remote Sensing; Data Integration and Geographic Information Systems
Thompson, M. D.
A pilot program carried out in Western Canada to test remote sensing under semi-operational conditions and display its applicability to operational range management programs was described. Four agencies were involved in the program, two in Alberta and two in Manitoba. Each had different objectives and needs for remote sensing within its range management programs, and each was generally unfamiliar with remote sensing techniques and their applications. Personnel with experience and expertise in the remote sensing and range management fields worked with the agency personnel through every phase of the pilot program. Results indicate that these agencies have found remote sensing to be a cost effective tool and will begin to utilize remote sensing in their operational work during ensuing seasons.
Full Text Available Snow on Antarctic sea ice plays a key role for sea ice physical processes and complicates retrieval of sea ice thickness using altimetry. Current methods of snow depth retrieval are based on satellite microwave radiometry, which perform best for dry, homogeneous snow packs on level sea ice. We introduce an alternative approach based on in-situ measurements of total (sea ice plus snow freeboard and snow depth, which we use to compute snow depth on sea ice from Ice, Cloud, and land Elevation Satellite (ICESat total freeboard observations. We compare ICESat snow depth for early winter and spring of the years 2004 through 2006 with the Advanced Scanning Microwave Radiometer aboard EOS (AMSR-E snow depth product. We find ICESat snow depths agree more closely with ship-based visual and air-borne snow radar observations than AMSR-E snow depths. We obtain average modal and mean ICESat snow depths, which exceed AMSR-E snow depths by 5–10 cm in winter and 10–15 cm in spring. We observe an increase in ICESat snow depth from winter to spring for most Antarctic regions in accordance with ground-based observations, in contrast to AMSR-E snow depths, which we find to stay constant or to decrease. We suggest satellite laser altimetry as an alternative method to derive snow depth on Antarctic sea ice, which is independent of snow physical properties.
Saadoud, Djouher; Hassani, Mohamed; Martin Peinado, Francisco José; Guettouche, Mohamed Saïd
Wind erosion is one of the most serious environmental problems in Algeria that threatens human activities and socio-economic development. The main goal of this study is to apply a fuzzy logic approach to wind erosion sensitivity mapping in the Laghouat region, Algeria. Six causative factors, obtained by applying fuzzy membership functions to each used parameter, are considered: soil, vegetation cover, wind factor, soil dryness, land topography and land cover sensitivity. Different fuzzy operators (AND, OR, SUM, PRODUCT, and GAMMA) are applied to generate wind-erosion hazard map. Success rate curves reveal that the fuzzy gamma (γ) operator, with γ equal to 0.9, gives the best prediction accuracy with an area under curve of 85.2%. The resulting wind-erosion sensitivity map delineates the area into different zones of five relative sensitivity classes: very high, high, moderate, low and very low. The estimated result was verified by field measurements and the high statistically significant value of a chi-square test.
Kim, S.; Kim, H.; Choi, M.; Kim, K.
Estimating spatiotemporal variation of soil moisture is crucial to hydrological applications such as flood, drought, and near real-time climate forecasting. Recent advances in space-based passive microwave measurements allow the frequent monitoring of the surface soil moisture at a global scale and downscaling approaches have been applied to improve the spatial resolution of passive microwave products available at local scale applications. However, most downscaling methods using optical and thermal dataset, are valid only in cloud-free conditions; thus renewed downscaling method under all sky condition is necessary for the establishment of spatiotemporal continuity of datasets at fine resolution. In present study Support Vector Machine (SVM) technique was utilized to downscale a satellite-based soil moisture retrievals. The 0.1 and 0.25-degree resolution of daily Land Parameter Retrieval Model (LPRM) L3 soil moisture datasets from Advanced Microwave Scanning Radiometer 2 (AMSR2) were disaggregated over Northeast Asia in 2015. Optically derived estimates of surface temperature (LST), normalized difference vegetation index (NDVI), and its cloud products were obtained from MODerate Resolution Imaging Spectroradiometer (MODIS) for the purpose of downscaling soil moisture in finer resolution under all sky condition. Furthermore, a comparison analysis between in situ and downscaled soil moisture products was also conducted for quantitatively assessing its accuracy. Results showed that downscaled soil moisture under all sky condition not only preserves the quality of AMSR2 LPRM soil moisture at 1km resolution, but also attains higher spatial data coverage. From this research we expect that time continuous monitoring of soil moisture at fine scale regardless of weather conditions would be available.
Hamid, Amna Ahmed; Ali, Mohamed M.
The main objective of the paper is to illustrate the potential of remote sensing data in the study and monitoring of environmental changes in western Sudan where considerable part of the area is under rangeland use. Data from NOAA satellite AVHRR sensor as well as thematic mapper Tm was used to assess the environment of the area during 1982-1997. The AVHRR data was processed into vegetation index (NDVI) images. Image analysis and classification was done using image display and analysis (IDA) GIS method to study vegetation condition in time series. The obtained information from field observations. The result showed high correlation between the information the work concluded the followings: NDVI images and thematic mapper data proved to be efficient in environment change analysis. NOAA AVHRR satellite data can provide an early-warning indicator of an approaching disaster. Remote sensing integrated into a GIS can contribute effectively to improve land management through better understanding of environment variability.(Author)
Smith, J.A.; Schmugge, T.J.; Ballard, J.R. Jr.
Land Surface Temperature (LST) is an important parameter in understanding global environmental change because it controls many of the underlying processes in the energy budget at the surface and heat and water transport between the surface and the atmosphere. The measurement of LST at a variety of spatial and temporal scales and extension to global coverage requires remote sensing means to achieve these goals. Land surface temperature and emissivity products are currently being derived from satellite and aircraft remote sensing data using a variety of techniques to correct for atmospheric effects. Implicit in the commonly employed approaches is the assumption of isotropy in directional thermal infrared exitance. The theoretical analyses indicate angular variations in apparent infrared temperature will typically yield land surface temperature errors ranging from 1 to 4 C unless corrective measures are applied
M. L. Jarman
Full Text Available The kinds of imagery, types of data and general relationships between scale of study, scale of mapping and scale of remote sensing products that are appropriate to the South African situation for visual and digital analysis are presented. The type of remote sensing product and processing, the type of field exercise appropriate to each, and the purpose of producing maps at each scale are discussed. Lack of repetitive imagery to date has not allowed for the full investigation of monitoring potential and careful planning at national level is needed to ensure availability of imagery for monitoring purposes. Map production processes which are rapid and accurate should be utilized. An integrated approach to vegetation mapping and surveying, which incorporates the best features of both visual and digital processing, is recommended for use.
Desa, E.; Brown, R.; Shenoi, S.S.C.; Joseph, G.
Conference (PORSEC), earlier known as the Paci c Ocean Remote Sensing Conference (PORSEC), was formed in 1992 to provide a venue for international cooperation in the increasingly important area of remote sensing of the ocean. Many countries that border... and ocean dynamics, and modeling with satellite sensor (mainly microwave) data. Some of the presentations are of regional interest, while others will nd an audience beyond the satellite remote sensing community. These rst results through their simple...
Remote sensing is a kind of very effective method which can be used in all stages of geological prospecting. Geological prospecting with remote sensing method must be based on different genetic models of ore deposits, characteristics of geology-landscape and comprehensive analysis for geophysical and geochemical data, that is, by way of conceptual model prospecting. The prospecting results based on remote sensing geology should be assessed from three aspects such as direct, indirect and potential ones
The Arctic Institute of North America long has been interested in encouraging full and specific attention to applications of remote sensing to polar...research problems. The major purpose of the symposium was to acquaint scientists and technicians concerned with remote sensing with some of the...special problems of the polar areas and, in turn, to acquaint polar scientists with the potential of the use of remote sensing . The Symposium therefore was
Full Text Available When observing the Earth from above at night, it is clear that the human settlement and major economic regions emit glorious light. At cloud-free nights, some remote sensing satellites can record visible radiance source, including city light, fishing boat light and fire, and these nighttime cloud-free images are remotely sensed nighttime light images. Different from daytime remote sensing, nighttime light remote sensing provides a unique perspective on human social activities, thus it has been widely used for spatial data mining of socioeconomic domains. Historically, researches on nighttime light remote sensing mostly focus on urban land cover and urban expansion mapping using DMSP/OLS imagery, but the nighttime light images are not the unique remote sensing source to do these works. Through decades of development of nighttime light product, the nighttime light remote sensing application has been extended to numerous interesting and scientific study domains such as econometrics, poverty estimation, light pollution, fishery and armed conflict. Among the application cases, it is surprising to see the Gross Domestic Production (GDP data can be corrected using the nighttime light data, and it is interesting to see mechanism of several diseases can be revealed by nighttime light images, while nighttime light are the unique remote sensing source to do the above works. As the nighttime light remote sensing has numerous applications, it is important to summarize the application of nighttime light remote sensing and its data mining fields. This paper introduced major satellite platform and sensors for observing nighttime light at first. Consequently, the paper summarized the progress of nighttime light remote sensing data mining in socioeconomic parameter estimation, urbanization monitoring, important event evaluation, environmental and healthy effects, fishery dynamic mapping, epidemiological research and natural gas flaring monitoring. Finally, future
Conradsen, K.; Nilsson, G.; Thyrsted, T.
A research project, aiming at investigation the use of remote sensing in uranium exploration, has been accomplished on data from South Greenland. During the project, analyses have been done on pure remote sensing data (Landsat MSS) and on integrated data of various types, including geochemical, aeromagnetic, radiometric and geological data in addition to the MSS data. Ratioing, factor analysis and discriminant analysis were used for enhancement of colour anomalies which correspond to oxidation zones. Some of the anomalies coincide with U and Nb mineralizations. Lineaments were mapped visually from photoprints, digitized and analysed statistically. A sinusoidal model could be applied to the general directional frequency distribution and was used to define ten classes of significant directions. Three of these directions were of major geological significance. Thus some of the major alkaline intrusions are situated at the intersections of some of the lineaments, a particular NE-SW trending lineament coincides with a geochemical boundary and pitchblende occurrences may be related to a WNW-ESE direction. The various types of data set were brought onto format of the Landsat images and collected in a data base. Representing three different types of data (Landsat MSS-band 7, aeromagnetic data and the geochemical Fe-content of stream sediments) on basis of intensity, hue and saturation revealed new features among which can be mentioned a possible indication of a subsurface continuation of one of the major alkaline intrusions. (author)
This paper presents a study for linking remotely sensed data with property tax related issues. First, it discusses the key attributes required for property taxation and evaluates the capabilities of remote sensing technology to measure these attributes accurately at parcel level. Next, it presents a detailed case study of six representative wards of different characteristics in Dehradun, India, that illustrates how measurements of several of these attributes supported by field survey can be combined to address the issues related to property taxation. Information derived for various factors quantifies the property taxation contributed by an average dwelling unit of the different income groups. Results show that the property tax calculated in different wards varies between 55% for the high-income group, 32% for the middle-income group, 12% for the low-income group and 1% for squatter units. The study concludes that higher spatial resolution satellite data and integrates social survey helps to assess the socio-economic status of the population for tax contribution purposes.
Full Text Available For agronomic, environmental, and economic reasons, the need for spatialized information about agricultural practices is expected to rapidly increase. In this context, we reviewed the literature on remote sensing for mapping cropping practices. The reviewed studies were grouped into three categories of practices: crop succession (crop rotation and fallowing, cropping pattern (single tree crop planting pattern, sequential cropping, and intercropping/agroforestry, and cropping techniques (irrigation, soil tillage, harvest and post-harvest practices, crop varieties, and agro-ecological infrastructures. We observed that the majority of the studies were exploratory investigations, tested on a local scale with a high dependence on ground data, and used only one type of remote sensing sensor. Furthermore, to be correctly implemented, most of the methods relied heavily on local knowledge on the management practices, the environment, and the biological material. These limitations point to future research directions, such as the use of land stratification, multi-sensor data combination, and expert knowledge-driven methods. Finally, the new spatial technologies, and particularly the Sentinel constellation, are expected to improve the monitoring of cropping practices in the challenging context of food security and better management of agro-environmental issues.
Sorek-Hamer, Meytar; Just, Allan C; Kloog, Itai
Particulate matter air pollution is a ubiquitous exposure linked with multiple adverse health outcomes for children and across the life course. The recent development of satellite-based remote-sensing models for air pollution enables the quantification of these risks and addresses many limitations of previous air pollution research strategies. We review the recent literature on the applications of satellite remote sensing in air quality research, with a focus on their use in epidemiological studies. Aerosol optical depth (AOD) is a focus of this review and a significant number of studies show that ground-level particulate matter can be estimated from columnar AOD. Satellite measurements have been found to be an important source of data for particulate matter model-based exposure estimates, and recently have been used in health studies to increase the spatial breadth and temporal resolution of these estimates. It is suggested that satellite-based models improve our understanding of the spatial characteristics of air quality. Although the adoption of satellite-based measures of air quality in health studies is in its infancy, it is rapidly growing. Nevertheless, further investigation is still needed in order to have a better understanding of the AOD contribution to these prediction models in order to use them with higher accuracy in epidemiological studies.
Bishop, W. P.; Heacock, E. L.
The current offer by the United States Department of Commerce to transfer the U.S. land remote sensing program to the private sector is described. A Request for Proposals (RFP) was issued, soliciting offers from U.S. firms to provide a commercial land remote sensing satellite system. Proposals must address a complete system including satellite, communications, and ground data processing systems. Offerors are encouraged to propose to take over the Government LANDSAT system which consists of LANDSAT 4 and LANDSAT D'. Also required in proposals are the market development procedures and plans to ensure that commercialization is feasible and the business will become self-supporting at the earliest possible time. As a matter of Federal Policy, the solicitation is designed to protect both national security and foreign policy considerations. In keeping with these concerns, an offeror must be a U.S. Firm. Requirements for data quality, quantity, distribution and delivery are met by current operational procedures. It is the Government's desire that the Offeror be prepared to develop and operate follow-on systems without Government subsidies. However, to facilitate rapid commercialization, an offeror may elect to include in his proposal mechanisms for short term government financial assistance.
Estes, J. E.; Jensen, J. R.; Tinney, L. R.; Rector, M.
In an attempt to determine the ability of remote sensing techniques to economically generate data required by water demand models, the Geography Remote Sensing Unit, in conjunction with the Kern County Water Agency of California, developed an analysis model. As a result it was determined that agricultural cropland inventories utilizing both high altitude photography and LANDSAT imagery can be conducted cost effectively. In addition, by using average irrigation application rates in conjunction with cropland data, estimates of agricultural water demand can be generated. However, more accurate estimates are possible if crop type, acreage, and crop specific application rates are employed. An analysis of the effect of saline-alkali soils on water demand in the study area is also examined. Finally, reference is made to the detection and delineation of water tables that are perched near the surface by semi-permeable clay layers. Soil salinity prediction, automated crop identification on a by-field basis, and a potential input to the determination of zones of equal benefit taxation are briefly touched upon.
El-Askary, H. M.; Sheta, W.; Prasad, A. K.; Ali, H.; Abdel rahman, M.; El-Desouki, A.; Kafatos, M.
Water Vapor Low Mean, Atmospheric Water Vapor Mean, Mass Concentration Land Mean, Optical Depth Ratio Small Land and Ocean Mean, Small Mode Optical Depth Land and Ocean Mean, Cloud Top Pressure Day Mean, Cloud Top Pressure Mean, Cloud Top Temperature Mean. The suggested linear Genetic approach detected hidden anomalies and relationships that cannot be observed from the conventional statistical methods. A well-established model as an important contribution to show the relationships between particle size and the physical and chemical aerosols properties has been designed. Such coupling will provide insight into the micro physics of the phenomenon. The proposed research will reveal previously uncharacterized yet fundamental relations and dependencies among aerosols, cloud and meteorological related parameters. Moreover, it would aid in filling gaps of missing satellite parameters using other available ones.
Senay, G.B.; Budde, Michael; Verdin, J.P.; Melesse, Assefa M.
upstream and downstream basins. A major advantage of the energy-balance approach is that it can be used to quantify spatial extent of irrigated fields and their water-use dynamics without reference to source of water as opposed to a water-balance model which requires knowledge of both the magnitude and temporal distribution of rainfall and irrigation applied to fields. ?? 2007 by MDPI.
Angeluccetti, Irene; Perez, Francesca; Cámaro, Walther; Demarchi, Alessandro
Early Warning Systems (EWS) for drought are currently underdeveloped compared to those related to other natural hazards. Both forecasting and monitoring of drought events are still posing challenges to the scientific community. In fact, the multifaceted nature of drought (i.e. hydrological, meteorological, and agricultural) is source of coexistence for different ways to measure this phenomenon and its effects. Similarly, drought impacts are various and complex thus difficult to be univocally measured. In the present study an approach for monitoring drought in near-real time and for estimating its impacts is presented. The EWS developed runs on a global extent and is mainly based on the early detection and monitoring of vegetation stress. On the one hand the monitoring of vegetation phenological parameters, whose extraction is based on the analysis of the MODIS-derived NDVI function, allows the fortnightly assessment of the vegetation productivity which could be expected at the end of the growing season. On the other hand, the Standardized Precipitation Index (SPI), calculated adapting TRMM-derived precipitation data in a selected distribution is used, before the growing season start, in order to early detect meteorological conditions which could give rise to vegetation stress events. During the growing season the SPI is used as check information for vegetation conditions. The relationships between rainfall and vegetation dynamics have been statistically analyzed considering different types of vegetation, in order to identify the most suitable rainfall cumulating interval to be used for the proposed monitoring procedures in different areas. A simplified vulnerability model, coupled with the above-mentioned hazard data, returns food security conditions, i.e. the estimated impacts over an investigated area. The model includes a set of agricultural indicators that accounts for the diversity of cultivated crops, the percentage of irrigated area and the suitability of
Havaej, Mohsen; Coggan, John; Stead, Doug; Elmo, Davide
Rock slope geometry and discontinuity properties are among the most important factors in realistic rock slope analysis yet they are often oversimplified in numerical simulations. This is primarily due to the difficulties in obtaining accurate structural and geometrical data as well as the stochastic representation of discontinuities. Recent improvements in both digital data acquisition and incorporation of discrete fracture network data into numerical modelling software have provided better tools to capture rock mass characteristics, slope geometries and digital terrain models allowing more effective modelling of rock slopes. Advantages of using improved data acquisition technology include safer and faster data collection, greater areal coverage, and accurate data geo-referencing far exceed limitations due to orientation bias and occlusion. A key benefit of a detailed point cloud dataset is the ability to measure and evaluate discontinuity characteristics such as orientation, spacing/intensity and persistence. This data can be used to develop a discrete fracture network which can be imported into the numerical simulations to study the influence of the stochastic nature of the discontinuities on the failure mechanism. We demonstrate the application of digital terrestrial photogrammetry in discontinuity characterization and distinct element simulations within a slate quarry. An accurately geo-referenced photogrammetry model is used to derive the slope geometry and to characterize geological structures. We first show how a discontinuity dataset, obtained from a photogrammetry model can be used to characterize discontinuities and to develop discrete fracture networks. A deterministic three-dimensional distinct element model is then used to investigate the effect of some key input parameters (friction angle, spacing and persistence) on the stability of the quarry slope model. Finally, adopting a stochastic approach, discrete fracture networks are used as input for 3D
Salvucci, Guido D.
The overall goal of this research is to examine the feasibility of applying a newly developed diagnostic model of soil water evaporation to large land areas using remotely sensed input parameters. The model estimates the rate of soil evaporation during periods when it is limited by the net transport resulting from competing effects of capillary rise and drainage. The critical soil hydraulic properties are implicitly estimated via the intensity and duration of the first stage (energy limited) evaporation, removing a major obstacle in the remote estimation of evaporation over large areas. This duration, or 'time to drying' (t(sub d)) is revealed through three signatures detectable in time series of remote sensing variables. The first is a break in soil albedo that occurs as a small vapor transmission zone develops near the surface. The second is a break in either surface to air temperature differences or in the diurnal surface temperature range, both of which indicate increased sensible heat flux (and/or storage) required to balance the decrease in latent heat flux. The third is a break in the temporal pattern of near surface soil moisture. Soil moisture tends to decrease rapidly during stage I drying (as water is removed from storage), and then become more or less constant during soil limited, or 'stage II' drying (as water is merely transmitted from deeper soil storage). The research tasks address: (1) improvements in model structure, including extensions to transpiration and aggregation over spatially variable soil and topographic landscape attributes; and (2) applications of the model using remotely sensed input parameters.
Jones, C. E.; Bawden, G. W.; Deverel, S. J.; Dudas, J.; Hensley, S.; Yun, S.
Remote sensing offers the potential to augment current levee monitoring programs by providing rapid and consistent data collection over large areas irrespective of the ground accessibility of the sites of interest, at repeat intervals that are difficult or costly to maintain with ground-based surveys, and in rapid response to emergency situations. While synthetic aperture radar (SAR) has long been used for subsidence measurements over large areas, applying this technique directly to regional levee monitoring is a new endeavor, mainly because it requires both a wide imaging swath and fine spatial resolution to resolve individual levees within the scene, a combination that has not historically been available. Application of SAR remote sensing directly to levee monitoring has only been attempted in a few pilot studies. Here we describe how SAR remote sensing can be used to assess levee conditions, such as seepage, drawing from the results of two levee studies: one of the Sacramento-San Joaquin Delta levees in California that has been ongoing since July 2009 and a second that covered the levees near Vicksburg, Mississippi, during the spring 2011 floods. These studies have both used data acquired with NASA's UAVSAR L-band synthetic aperture radar, which has the spatial resolution needed for this application (1.7 m single-look), sufficiently wide imaging swath (22 km), and the longer wavelength (L-band, 0.238 m) required to maintain phase coherence between repeat collections over levees, an essential requirement for applying differential interferometry (DInSAR) to a time series of repeated collections for levee deformation measurement. We report the development and demonstration of new techniques that employ SAR polarimetry and differential interferometry to successfully assess levee health through the quantitative measurement of deformation on and near levees and through detection of areas experiencing seepage. The Sacramento-San Joaquin Delta levee study, which covers
Walker, D.A.; Bhatt, U.S.; Breen, A.L.
A circumpolar view of Arctic vegetation developed with the advent of satellite-derived remote-sensing products. Interpretations of what the revealed patterns mean are dependent on a foundation of in-situ plot-based observations. Despite the importance of ground-based observations, only a few areas...... of species composition, canopy structure, biomass, leaf-area index, and NDVI, along with high-resolution satellite-based remote-sensing products at the same time....... classification, plot markings, and standardized approaches to describe the local environment, including photo points showing the vegetation and soils up close and in landscape view. (3) Standardized approaches for collecting in-situ time-series of spectral data. Standardized methods for collecting and analyzing...
Schüttler, Tobias; Maman, Shimrit; Girwidz, Raimund
Context- and project-based teaching has proven to foster different affective and cognitive aspects of learning. As a versatile and multidisciplinary scientific research area with diverse applications for everyday life, satellite remote sensing is an interesting context for physics education. In this paper we give a brief overview of satellite remote sensing of vegetation and how to obtain your own, individual infrared remote sensing data with affordable converted digital cameras. This novel technique provides the opportunity to conduct individual remote sensing measurement projects with students in their respective environment. The data can be compared to real satellite data and is of sufficient accuracy for educational purposes.
Chen, Siya; Sun, Tieli; Yang, Fengqin; Sun, Hongguang; Guan, Yu
Remote sensing image segmentation is a key technology for processing remote sensing images. The image segmentation results can be used for feature extraction, target identification and object description. Thus, image segmentation directly affects the subsequent processing results. This paper proposes a novel Optimum-Path Forest (OPF) clustering algorithm that can be used for remote sensing segmentation. The method utilizes the principle that the cluster centres are characterized based on their densities and the distances between the centres and samples with higher densities. A new OPF clustering algorithm probability density function is defined based on this principle and applied to remote sensing image segmentation. Experiments are conducted using five remote sensing land cover images. The experimental results illustrate that the proposed method can outperform the original OPF approach.
Mangroves are integral to ecosystem services provided by the coastal zone, in particular carbon (C) sequestration and storage. Allometric relationships linking mangrove height to estimated biomass and C stocks have been developed from field sampling, while various forms of remote sensing has been used to map vegetation height and biomass. Here we combine both these approaches to investigate spatial patterns in living biomass of mangrove forests in a small area of mangrove in north-west Australia. This study used LiDAR data and Landsat 8 OLI (Operational Land Imager) with allometric equations to derive mangrove height, biomass, and C stock estimates. We estimated the study site, Mangrove Bay, a semi-arid site in north-western Australia, contained 70 Mg ha−1 biomass and 45 Mg C ha−1 organic C, with total stocks of 2417 Mg biomass and 778 Mg organic C. Using spatial statistics to identify the scale of clustering of mangrove pixels, we found that living biomass and C stock declined with increasing distance from hydrological features (creek entrance: 0–150 m; y = −0.00041x + 0.9613, R2 = 0.96; 150–770 m; y = −0.0008x + 1.6808, R2 = 0.73; lagoon: y = −0.0041x + 3.7943, R2 = 0.78). Our results illustrate a set pattern of living C distribution within the mangrove forest, and then highlight the role hydrologic features play in determining C stock distribution in arid zone.
Thatch, L. M.; Maxwell, R. M.; Gilbert, J. M.
Over the past century, groundwater levels in California's San Joaquin Valley have dropped more than 30 meters in some areas due to excessive groundwater extraction to irrigate agricultural lands and feed a growing population. Between 2012 and 2016 California experienced the worst drought in its recorded history, further exacerbating this groundwater depletion. Due to lack of groundwater regulation, exact quantities of extracted groundwater in California are unknown and hard to quantify. We use a synthesis of integrated hydrologic model simulations and remote sensing products to quantify the impact of drought and groundwater pumping on the Central Valley water tables. The Parflow-CLM model was used to evaluate groundwater depletion in the San Joaquin River basin under multiple groundwater extraction scenarios simulated from pre-drought through recent drought years. Extraction scenarios included pre-development conditions, with no groundwater pumping; historical conditions based on decreasing groundwater level measurements; and estimated groundwater extraction rates calculated from the deficit between the predicted crop water demand, based on county land use surveys, and available surface water supplies. Results were compared to NASA's Gravity Recover and Climate Experiment (GRACE) data products to constrain water table decline from groundwater extraction during severe drought. This approach untangles various factors leading to groundwater depletion within the San Joaquin Valley both during drought and years of normal recharge to help evaluate which areas are most susceptible to groundwater overdraft, as well as further evaluating the spatially and temporally variable sustainable yield. Recent efforts to improve water management and ensure reliable water supplies are highlighted by California's Sustainable Groundwater Management Act (SGMA) which mandates Groundwater Sustainability Agencies to determine the maximum quantity of groundwater that can be withdrawn through
Satellite remote sensing (RS) has emerged as a cutting edge approach for estimating ground level ambient air pollution. Previous studies have reported a high correlation between ground level PM2.5 and NO2 estimated by RS and measurements collected at regulatory monitoring sites. The current study examined associations between air pollution and adverse respiratory and allergic health outcomes using multi-year averages of NO2 and PM2.5 from RS and from regulatory monitoring. RS estimates were derived using satellite measurements from OMI, MODIS, and MISR instruments. Regulatory monitoring data were obtained from Canada's National Air Pollution Surveillance Network. Self-reported prevalence of doctor-diagnosed asthma, current asthma, allergies, and chronic bronchitis were obtained from the Canadian Community Health Survey (a national sample of individuals 12 years of age and older). Multi-year ambient pollutant averages were assigned to each study participant based on their six digit postal code at the time of health survey, and were used as a marker for long-term exposure to air pollution. RS derived estimates of NO2 and PM2.5 were associated with 6e10% increases in respiratory and allergic health outcomes per interquartile range (3.97 mg m3 for PM2.5 and 1.03 ppb for NO2) among adults (aged 20e64) in the national study population. Risk estimates for air pollution and respiratory/ allergic health outcomes based on RS were similar to risk estimates based on regulatory monitoring for areas where regulatory monitoring data were available (within 40 km of a regulatory monitoring station). RS derived estimates of air pollution were also associated with adverse health outcomes among participants residing outside the catchment area of the regulatory monitoring network (p < 0.05).
Riccio, Giovanni; Gennarelli, Claudio
A Trihedral Corner Reflector (TCR) is formed by three mutually orthogonal metal plates of various shapes and is a very important scattering structure since it exhibits a high monostatic Radar Cross Section (RCS) over a wide angular range. Moreover it is a handy passive device with low manufacturing costs and robust geometric construction, the maintenance of its efficiency is not difficult and expensive, and it can be used in all weather conditions (i.e., fog, rain, smoke, and dusty environment). These characteristics make it suitable as reference target and radar enhancement device for satellite- and ground-based microwave remote sensing techniques. For instance, TCRs have been recently employed to improve the signal-to-noise ratio of the backscattered signal in the case of urban ground deformation monitoring and dynamic survey of civil infrastructures without natural corners as the Musmeci bridge in Basilicata, Italy . The region of interest for the calculation of TCR's monostatic RCS is here confined to the first quadrant containing the boresight direction. The backscattering term is presented in closed form by evaluating the far-field scattering integral involving the contributions related to the direct illumination and the internal bouncing mechanisms. The Geometrical Optics (GO) laws allow one to determine the field incident on each TCR plate and the patch (integration domain) illuminated by it, thus enabling the use of a Physical Optics (PO) approximation for the corresponding surface current densities to consider for integration on each patch. Accordingly, five contributions are associated to each TCR plate: one contribution is due to the direct illumination of the whole internal surface; two contributions originate by the impinging rays that are simply reflected by the other two internal surfaces; and two contributions are related to the impinging rays that undergo two internal reflections. It is useful to note that the six contributions due to the
Hayden, L. B.; Johnson, D.; Baltrop, J.
Remote sensing has steadily become an integral part of multiple disciplines, research, and education. Remote sensing can be defined as the process of acquiring information about an object or area of interest without physical contact. As remote sensing becomes a necessity in solving real world problems and scientific questions an important question to consider is why remote sensing training is significant to education and is it relevant to training students in this discipline. What has been discovered is the interest in Science, Technology, Engineering and Mathematics (STEM) fields, specifically remote sensing, has declined in our youth. The Center of Excellence in Remote Sensing Education and Research (CERSER) continuously strives to provide education and research opportunities on ice sheet, coastal, ocean, and marine science. One of those continued outreach efforts are Center for Remote Sensing of Ice Sheets (CReSIS) Middle School Program. Sponsored by the National Science Foundation CReSIS Middle School Program offers hands on experience for middle school students. CERSER and NSF offer students the opportunity to study and learn about remote sensing and its vital role in today's society as it relate to climate change and real world problems. The CReSIS Middle School Program is an annual two-week effort that offers middle school students experience with remote sensing and its applications. Specifically, participants received training with Global Positioning Systems (GPS) where the students learned the tools, mechanisms, and applications of a Garmin 60 GPS. As a part of the program the students were required to complete a fieldwork assignment where several longitude and latitude points were given throughout campus. The students had to then enter the longitude and latitude points into the Garmin 60 GPS, navigate their way to each location while also accurately reading the GPS to make sure travel was in the right direction. Upon completion of GPS training the
Tinney, L. R.; Jensen, J. R.; Estes, J. E.
A remote sensing analysis of the amount and type of permeable and impermeable surfaces overlying an urban recharge basin is discussed. An effective methodology for accurately generating this data as input to a safe yield study is detailed and compared to more conventional alternative approaches. The amount of area inventoried, approximately 10 sq. miles, should provide a reliable base against which automatic pattern recognition algorithms, currently under investigation for this task, can be evaluated. If successful, such approaches can significantly reduce the time and effort involved in obtaining permeability data, an important aspect of urban hydrology dynamics.
Prados, Donald; Johnson, Michael; Mohamed, Mohamed A.; Cao, Chang-Yong; Gasser, Jerry; Powell, Don; McGregor, Lloyd
This paper presents results of a project to port code for processing remotely sensed data from the UNIX environment to Windows. Factors considered during this process include time schedule, cost, resource availability, reuse of existing code, rapid interface development, ease of integration, and platform independence. The approach selected for this project used both Java and C. By using Java for the graphical user interface and C for the domain model, the strengths of both languages were utilized and the resulting code can easily be ported to other platforms. The advantages of this approach are discussed in this paper.
Xing, Xiao-Gang; Zhao, Dong-Zhi; Liu, Yu-Guang; Yang, Jian-Hong; Xiu, Peng; Wang, Lin
Besides empirical algorithms with the blue-green ratio, the algorithms based on fluorescence are also important and valid methods for retrieving chlorophyll-a concentration in the ocean waters, especially for Case II waters and the sea with algal blooming. This study reviews the history of initial cognitions, investigations and detailed approaches towards chlorophyll fluorescence, and then introduces the biological mechanism of fluorescence remote sensing and main spectral characteristics such as the positive correlation between fluorescence and chlorophyll concentration, the red shift phenomena. Meanwhile, there exist many influence factors that increase complexity of fluorescence remote sensing, such as fluorescence quantum yield, physiological status of various algae, substances with related optical property in the ocean, atmospheric absorption etc. Based on these cognitions, scientists have found two ways to calculate the amount of fluorescence detected by ocean color sensors: fluorescence line height and reflectance ratio. These two ways are currently the foundation for retrieval of chlorophyl l - a concentration in the ocean. As the in-situ measurements and synchronous satellite data are continuously being accumulated, the fluorescence remote sensing of chlorophyll-a concentration in Case II waters should be recognized more thoroughly and new algorithms could be expected.
Vangenderen, J. L.; Lock, B. F.; Vass, P. A.
Some of the main aspects that need to be considered in a remote sensing sampling design are: (1) the frequency that any one land use type (on the ground) is erroneously attributed to another class by the interpreter; (2) the frequency that the wrong land use (as observed on the ground) is erroneously included in any one class by the remote sensing interpreter; (3) the proportion of all land (as determined in the field) that is mistakenly attributed by the interpreter; and (4) the determination of whether the mistakes are random (so that the overall proportions are approximately correct) or subject to a persistent bias. A sampling and statistical testing procedure is presented which allows an approximate answer to each of these aspects. The concept developed and described incorporates the probability of making incorrect interpretations at particular prescribed accuracy levels, for a certain number of errors, for a particular sample size. It is considered that this approach offers a meaningful explanation of the interpretation accuracy level of an entire remote sensing land use survey.
Full Text Available Despite being the driest inhabited continent, Australia has one of the highest per capita water consumptions in the world. In addition, instead of having fit-for-purpose water supplies (using different qualities of water for different applications, highly treated drinking water is used for nearly all of Australia’s urban water supply needs, including landscape irrigation. The water requirement of urban landscapes, particularly urban parklands, is of growing concern. The estimation of evapotranspiration (ET and subsequently plant water requirements in urban vegetation needs to consider the heterogeneity of plants, soils, water, and climate characteristics. This research contributes to a broader effort to establish sustainable irrigation practices within the Adelaide Parklands in Adelaide, South Australia. In this paper, two practical ET estimation approaches are compared to a detailed Soil Water Balance (SWB analysis over a one year period. One approach is the Water Use Classification of Landscape Plants (WUCOLS method, which is based on expert opinion on the water needs of different classes of landscape plants. The other is a remote sensing approach based on the Enhanced Vegetation Index (EVI from Moderate Resolution Imaging Spectroradiometer (MODIS sensors on the Terra satellite. Both methods require knowledge of reference ET calculated from meteorological data. The SWB determined that plants consumed 1084 mm·yr−1 of water in ET with an additional 16% lost to drainage past the root zone, an amount sufficient to keep salts from accumulating in the root zone. ET by MODIS EVI was 1088 mm·yr−1, very close to the SWB estimate, while WUCOLS estimated the total water requirement at only 802 mm·yr−1, 26% lower than the SWB estimate and 37% lower than the amount actually added including the drainage fraction. Individual monthly ET by MODIS was not accurate, but these errors were cancelled out to give good agreement on an annual time step. We
Carbonneau, P.; Dugdale, S. J.
Despite a decade of progress in the field of fluvial remote sensing, there are few published works using this new technology to advance and explore fundamental ideas and theories in fluvial geomorphology. This paper will apply remote sensing methods in order to re-visit a classic concept in fluvial geomorphology: flow resistance. Classic flow resistance equations such as those of Strickler and Keulegan typically use channel slope, channel depth or hydraulic radius and some measure channel roughness usually equated to the 50th or 84th percentile of the bed material size distribution. In this classic literature, empirical equations such as power laws are usually calibrated and validated with a maximum of a few hundred data points. In contrast, fluvial remote sensing methods are now capable of delivering millions of high resolution data points in continuous, catchment scale, surveys. On the river Tromie in Scotland, a full dataset or river characteristics is now available. Based on low altitude imagery and NextMap topographic data, this dataset has a continuous sampling of channel width at a resolution of 3cm, of depth and median grain size at a resolution of 1m, and of slope at a resolution of 5m. This entire data set is systematic and continuous for the entire 20km length of the river. When combined with discharge at the time of data acquisition, this new dataset offers the opportunity to re-examine flow resistance equations with a 2-4 orders of magnitude increase in calibration data. This paper will therefore re-examine the classic approaches of Strickler and Keulagan along with other more recent flow resistance equations. Ultimately, accurate predictions of flow resistance from remotely sensed parameters could lead to acceptable predictions of velocity. Such a usage of classic equations to predict velocity could allow lotic habitat models to account for microhabitat velocity at catchment scales without the recourse to advanced and computationally intensive
Kanniah, Kasturi D.; Kamarul Zaman, Nurul A. F.
The aerosol system is Southeast Asia is complex and the high concentrations are due to population growth, rapid urbanization and development of SEA countries. Nevertheless, only a few studies have been carried out especially at large spatial extent and on a continuous basis to study atmospheric aerosols in Malaysia. In this review paper we report the use of remote sensing data to study atmospheric aerosols in Malaysia and document gaps and recommend further studies to bridge the gaps. Satellite data have been used to study the spatial and seasonal patterns of aerosol optical depth (AOD) in Malaysia. Satellite data combined with AERONET data were used to delineate different types and sizes of aerosols and to identify the sources of aerosols in Malaysia. Most of the aerosol studies performed in Malaysia was based on station-based PM10 data that have limited spatial coverage. Thus, satellite data have been used to extrapolate and retrieve PM10 data over large areas by correlating remotely sensed AOD with ground-based PM10. Realising the critical role of aerosols on radiative forcing numerous studies have been conducted worldwide to assess the aerosol radiative forcing (ARF). Such studies are yet to be conducted in Malaysia. Although the only source of aerosol data covering large region in Malaysia is remote sensing, satellite observations are limited by cloud cover, orbital gaps of satellite track, etc. In addition, relatively less understanding is achieved on how the atmospheric aerosol interacts with the regional climate system. These gaps can be bridged by conducting more studies using integrated approach of remote sensing, AERONET and ground based measurements.
Stumpf, Rick P; Davis, Timothy W.; Wynne, Timothy T.; Graham, Jennifer L.; Loftin, Keith A.; Johengen, T.H.; Gossiaux, D.; Palladino, D.; Burtner, A.
Using satellite imagery to quantify the spatial patterns of cyanobacterial toxins has several challenges. These challenges include the need for surrogate pigments – since cyanotoxins cannot be directly detected by remote sensing, the variability in the relationship between the pigments and cyanotoxins – especially microcystins (MC), and the lack of standardization of the various measurement methods. A dual-model strategy can provide an approach to address these challenges. One model uses either chlorophyll-a (Chl-a) or phycocyanin (PC) collected in situ as a surrogate to estimate the MC concentration. The other uses a remote sensing algorithm to estimate the concentration of the surrogate pigment. Where blooms are mixtures of cyanobacteria and eukaryotic algae, PC should be the preferred surrogate to Chl-a. Where cyanobacteria dominate, Chl-a is a better surrogate than PC for remote sensing. Phycocyanin is less sensitive to detection by optical remote sensing, it is less frequently measured, PC laboratory methods are still not standardized, and PC has greater intracellular variability. Either pigment should not be presumed to have a fixed relationship with MC for any water body. The MC-pigment relationship can be valid over weeks, but have considerable intra- and inter-annual variability due to changes in the amount of MC produced relative to cyanobacterial biomass. To detect pigments by satellite, three classes of algorithms (analytic, semi-analytic, and derivative) have been used. Analytical and semi-analytical algorithms are more sensitive but less robust than derivatives because they depend on accurate atmospheric correction; as a result derivatives are more commonly used. Derivatives can estimate Chl-a concentration, and research suggests they can detect and possibly quantify PC. Derivative algorithms, however, need to be standardized in order to evaluate the reproducibility of parameterizations between lakes. A strategy for producing useful estimates
Raju, P. L. N.; Gupta, P. K.
One of the prime activities of Indian Space Research Organisation's (ISRO) Space Program is providing satellite communication services, viz., television broadcasting, mobile communication, cyclone disaster warning and rescue operations etc. so as to improve their economic conditions, disseminate technical / scientific knowledge to improve the agriculture production and education for rural people of India. ISRO, along with National Aeronautical and Space Administration (NASA) conducted experimental satellite communication project i.e. Satellite Instructional Television Experiment (SITE) using NASA's Advanced Telecommunication Satellite (i.e. ATS 6) with an objective to educate poor people of India via satellite broadcasting in 1975 and 1976, covering more than 2600 villages in six states of India and territories. Over the years India built communication satellites indigenously to meet the communication requirements of India. This has further lead to launch of an exclusive satellite from ISRO for educational purposes i.e. EDUSAT in 2004 through which rich audio-video content is transmitted / received, recreating virtual classes through interactivity. Indian Institute of Remote Sensing (IIRS) established in 1966, a premier institute in south East Asia in disseminating Remote Sensing (RS) and Geographical Information System (GIS), mainly focusing on contact based programs. But expanded the scope with satellite based Distance Learning Programs for Universities, utilizing the dedicated communication satellite i.e. EDUSAT in 2007. IIRS conducted successfully eight Distance Learning Programs in the last five years and training more than 6000 students mainly at postgraduate level from more than 60 universities /Institutions spread across India. IIRS obtained feedback and improved the programs on the continuous basis. Expanded the scope of IIRS outreach program to train user departments tailor made in any of the applications of Remote Sensing and Geoinformation, capacity
Buffalano, A. C.; Kochanowski, P.
Remote sensing of agricultural land permits crop classification and mensuration which can lead to improved forecasts of production. This technique is particularly important for nations which do not already have an accurate agricultural reporting system. Better forecasts have important economic effects. International grain traders can make better decisions about when to store, buy, and sell. Farmers can make better planting decisions by taking advantage of production estimates for areas out of phase with their own agricultural calendar. World economic benefits will accrue to both buyers and sellers because of increased food supply and price stabilization. This paper reviews the econometric models used to establish this scenario and estimates the dollar value of benefits for world wheat as 200 million dollars annually for the United States and 300 to 400 million dollars annually for the rest of the world.
Siegal, B.S.; Welby, C.W.
It is shown that satellite remote sensing provides timely and cost-effective information for siting and site evaluation of nuclear power plants. Side-looking airborne radar (SLAR) imagery is especially valuable in regions of prolonged cloud cover and haze, and provides additional assurance in siting and licensing. In addition, a wide range of enhancement techniques should be employed and different types of image should be color-combined to provide structural and lithologic information. Coastal water circulation can also be studied through repetitive coverage and the inherently synoptic nature of imaging satellites. Among the issues discussed are snow cover, sun angle, and cloud cover, and actual site evaluation studies in the Bataan peninsula of the Philippines and Laguna Verde, California
Knowledge of the emission source strengths of different (particulate and gaseous) atmospheric constituents is one of the principal ingredients upon which the modeling and forecasting of their distribution and impacts depend. Biomass burning emissions are complex and difficult to quantify. However, satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP), which has a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. In this presentation, we will show how the satellite measurement of FRP is facilitating the quantitative characterization of biomass burning and smoke emission rates, and the implications of this unique capability for improving our understanding of smoke impacts on air quality, weather, and climate. We will also discuss some of the challenges and uncertainties associated with satellite measurement of FRP and how they are being addressed.
Porter, Reid B [Los Alamos National Laboratory; Hush, Do [Los Alamos National Laboratory; Harvey, Neal [Los Alamos National Laboratory; Theile, James [Los Alamos National Laboratory
To move from data to information in almost all science and defense applications requires a human-in-the-loop to validate information products, resolve inconsistencies, and account for incomplete and potentially deceptive sources of information. This is a key motivation for visual analytics which aims to develop techniques that complement and empower human users. By contrast, the vast majority of algorithms developed in machine learning aim to replace human users in data exploitation. In this paper we describe a recently introduced machine learning problem, called rare category detection, which may be a better match to visual analytic environments. We describe a new design criteria for this problem, and present comparisons to existing techniques with both synthetic and real-world datasets. We conclude by describing an application in broad-area search of remote sensing imagery.
Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John
A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.
Wang, Tianhe; Zhou, Tao; Jia, Xiaodong
The unmanned airborne (UAV) laser spectrum radar has played a leading role in remote sensing because the transmitter and the receiver are together at laser spectrum radar. The advantages of the integrated transceiver laser spectrum radar is that it can be used in the oil and gas pipeline leak detection patrol line which needs the non-contact reflective detection. The UAV laser spectrum radar can patrol the line and specially detect the swept the area are now in no man's land because most of the oil and gas pipelines are in no man's land. It can save labor costs compared to the manned aircraft and ensure the safety of the pilots. The UAV laser spectrum radar can be also applied in the post disaster relief which detects the gas composition before the firefighters entering the scene of the rescue.
Porter, Reid; Hush, Don; Harvey, Neal; Theiler, James
To move from data to information in almost all science and defense applications requires a human-in-the-loop to validate information products, resolve inconsistencies, and account for incomplete and potentially deceptive sources of information. This is a key motivation for visual analytics which aims to develop techniques that complement and empower human users. By contrast, the vast majority of algorithms developed in machine learning aim to replace human users in data exploitation. In this paper we describe a recently introduced machine learning problem, called rare category detection, which may be a better match to visual analytic environments. We describe a new design criteria for this problem, and present comparisons to existing techniques with both synthetic and real-world datasets. We conclude by describing an application in broad-area search of remote sensing imagery.
J. P. Stals
Full Text Available Earth observation (EO data is effective in monitoring agricultural cropping activity over large areas. An example of such an application is the GeoTerraImage crop type classification for the South African Crop Estimates Committee (CEC. The satellite based classification of crop types in South Africa provides a large scale, spatial and historical record of agricultural practices in the main crop growing areas. The results from these classifications provides data for the analysis of trends over time, in order to extract valuable information that can aid decision making in the agricultural sector. Crop cultivation practices change over time as farmers adapt to demand, exchange rate and new technology. Through the use of remote sensing, grain crop types have been identified at field level since 2008, providing a historical data set of cropping activity for the three most important grain producing provinces of Mpumalanga, Freestate and North West province in South Africa. This historical information allows the analysis of farm management practices to identify changes and trends in crop rotation and irrigation practices. Analysis of crop type classification over time highlighted practices such as: frequency of cultivation of the same crop on a field, intensified cultivation on centre pivot irrigated fields with double cropping of a winter grain followed by a summer grain in the same year and increasing cultivation of certain types of crops over time such as soyabeans. All these practices can be analysed in a quantitative spatial and temporal manner through the use of the remote sensing based crop type classifications.
Full Text Available Unmanned aerial vehicles (UAVs are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs.
Fujikawa, S; Uchida, K; Tanaka, S; Jingo, H [Dowa Engineering Co. Ltd., Tokyo (Japan); Hato, M [Earth Remote Sensing Data Analysis Center, Tokyo (Japan)
Recently, geological analysis using remote sensing data has been put into practice due to data with high spectral resolution and high spatial resolution. There has been a remarkable increase in both software and hardware of personal computer. Software is independent of hardware due to Windows. It has become easy to develop softwares. Under such situation, a portable remote sensing image processing system coping with Window 95 has been developed. Using this system, basic image processing can be conducted, and present location can be displayed on the image in real time by linking with GPS. Accordingly, it is not required to bring printed images for the field works of image processing. This system can be used instead of topographic maps for overseas surveys. Microsoft Visual C++ ver. 2.0 is used for the software. 1 fig.
Dozier J 1989a Remote sensing of snow in the visible and near-infrared wavelengths; In: Theory and Applications of. Optical Remote Sensing (ed.) Asrar G (New York: John. Wiley and Sons), pp. 527–547. Dozier J 1989b Spectral signature of alpine snow cover from the Landsat Thematic Mapper; Rem. Sens. Environ. 28.
Oevelen, van P.J.
In this thesis the use of microwave remote sensing to estimate soil water content is investigated. A general framework is described which is applicable to both passive and active microwave remote sensing of soil water content. The various steps necessary to estimate areal soil water content
present study, Remote Sensing (RS) and Geographical Information System (GIS) techniques were used. Remotely sensed .... growing stock in Tahno range of Dehradun Forest Division. Okhandiara (2008) .... areas on an image by identifying 'training' sites of known targets and then extrapolating those spectral signatures to ...
Sy, de V.; Herold, M.; Achard, F.; Asner, G.P.; Held, A.; Kellndorfer, J.; Verbesselt, J.
Remote sensing technologies can provide objective, practical and cost-effective solutions for developing and maintaining REDD+ monitoring systems. This paper reviews the potential and status of available remote sensing data sources with a focus on different forest information products and synergies
Seebach, Lucia Maria
the need for harmonised forest information can be satisfied using remote sensing methods. In conclusion, the study showed that it is possible to derive harmonised forest information of high spatial detail in Europe with remote sensing. The study also highlighted the imperative provision of accuracy...
Full Text Available at the coast is that it is in a permanent state of change. Remote sensing, whether from orbiting (space-borne) or air-borne platforms, can greatly assist in the task of monitoring coastal environments. In particular, remote sensing enables simultaneous or near...
Philip Riggan; Lynn Wolden; Bob Tissell; David Weise; J. Coen
Airborne remote sensing at infrared wavelengths has the potential to quantify large-fire properties related to energy release or intensity, residence time, fuel-consumption rate, rate of spread, and soil heating. Remote sensing at a high temporal rate can track fire-line outbreaks and acceleration and spotting ahead of a fire front. Yet infrared imagers and imaging...
Hasager, Charlotte Bay; Pena Diaz, Alfredo; Christiansen, Merete Bruun
Remote sensing observations used in offshore wind energy are described in three parts: ground-based techniques and applications, airborne techniques and applications, and satellite-based techniques and applications. Ground-based remote sensing of winds is relevant, in particular, for new large wind...
Remote sensing techniques enable quantitative information about a field trial to be obtained instantaneously and non-destructively. The aim of this study was to identify a method that can reduce inaccuracies in field trial analysis, and to identify how remote sensing can support and/or
Eisgruber, L. M.
A theoretical framwork is outlined for estimating social returns from research and application of remote sensing. The approximate dollar magnitude is given of a particular application of remote sensing, namely estimates of corn production, soybeans, and wheat. Finally, some comments are made on the limitations of this procedure and on the implications of results.
Weinstein, R. H.
Remote sensing is a principal focus of NASA's technology transfer program activity with major attention to remote sensing education the Regional Program and the University Applications Program. Relevant activities over the past five years are reviewed and perspective on future directions is presented.
Warren B. Cohen; Samuel N. Goward
Remote sensing, geographic information systems, and modeling have combined to produce a virtual explosion of growth in ecological investigations and applications that are explicitly spatial and temporal. Of all remotely sensed data, those acquired by landsat sensors have played the most pivotal role in spatial and temporal scaling. Modern terrestrial ecology relies on...
Internationally, a number of studies have successfully used remote sensing technology to monitor forest damage. Remote sensing technology allows for instantaneous methods of assessments whereby ground assessments would be impossible on a regular basis. This paper provides an overview of how advances in ...
To most land managers, remote sensing has remained illusive, seldom allowing the manager to use it to its full potential. In contrast, the policy maker, backed by GIS laboratories and remote sensing specialists, is confronted by plausible scenarios of degradation and transformation. After intervening, he is seldom active long ...
Zhang, Hong; Shen, Jinxiang; Ma, Yanmei
Multiscale segmentation of images can effectively form boundaries of different objects with different scales. However, for the remote sensing image which widely coverage with complicated ground objects, the number of suitable segmentation scales, and each of the scale size is still difficult to be accurately determined, which severely restricts the rapid information extraction of the remote sensing image. A great deal of experiments showed that the normalized difference vegetation index (NDVI) can effectively express the spectral characteristics of a variety of ground objects in remote sensing images. This paper presents a method using NDVI assisted adaptive segmentation of remote sensing images, which segment the local area by using NDVI similarity threshold to iteratively select segmentation scales. According to the different regions which consist of different targets, different segmentation scale boundaries could be created. The experimental results showed that the adaptive segmentation method based on NDVI can effectively create the objects boundaries for different ground objects of remote sensing images.
With the advent of Google Earth, Google Maps, and Microsoft Bing Maps, high resolution satellite imagery are becoming more easily accessible than ever. It have been the case that the college students may already have wealth experiences with the high resolution satellite imagery by using these software and web services prior to any formal remote sensing education. It is obvious that the remote sensing education should be adjusted to the fact that the audience are already the customers of remote sensing products (through the use of the above mentioned services). This paper reports the use of openly available satellite imagery in an introductory-level remote sensing course in the Department of Geomatics of National Cheng Kung University as a term project. From the experience learned from the fall of 2009 and 2010, it shows that this term project has effectively aroused the students' enthusiastic toward Remote Sensing.
Lutton, Stephen M.
Remote sensing is providing voluminous data and value added information products. Electronic sensors, communication electronics, computer software, hardware, and network communications technology have matured to the point where a distributed infrastructure for remotely sensed information is a reality. The amount of remotely sensed data and information is making distributed infrastructure almost a necessity. This infrastructure provides data collection, archiving, cataloging, browsing, processing, and viewing for applications from scientific research to economic, legal, and national security decision making. The remote sensing field is entering a new exciting stage of commercial growth and expansion into the mainstream of government and business decision making. This paper overviews this new distributed infrastructure and then focuses on describing a software system for on-line catalog access and distribution of remotely sensed information.
Plevin, J [ESA, Directorate of Planning and Future Programmes, Paris, France; Pryke, I [ESA, Directorate of Applications Programmes, Toulouse, France
The present activities and future missions of the ESA program of spaceborne remote sensing of earth resources and environment are discussed. Program objectives have been determined to be the satisfaction of European regional needs by agricultural, land use, water resources, coastal and polar surveys, and meeting the requirements of developing nations in the areas of agricultural production, mineral exploration and disaster warning and assessment. The Earthnet system of data processing centers presently is used for the distribution of remote sensing data acquired by NASA satellites. Remote sensing experiments to be flown aboard Spacelab are the Metric Camera, to test high resolution mapping capabilities of a large format camera, and the Microwave Remote-Sensing Experiment, which operates as a two-frequency scatterometer, a synthetic aperture radar and a passive microwave radiometer. Studies carried out on the definition of future remote sensing satellite systems are described, including studies of system concepts for land applications and coastal monitoring satellites.
Full Text Available Management strategies and silvicultural treatments of fire-prone ecosystems often rely on knowledge of the regeneration potential and long-term recovery ability of vegetation types. Remote sensing and GIS applications are valuable tools providing cost-efficient information on vegetation recovery patterns and their associated environmental factors. In this study we used an ordinal classification scheme to describe the land cover changes induced by a wildfire that occurred in 1983 in Pinus brutia woodlands on Karpathos Aegean Island, south-eastern Greece. As a proxy variable that indicates ecosystem recovery, we also estimated the difference between the NDVI and NBR indices a few months (1984 and almost 30 years after the fire (2012. Environmental explanatory variables were selected using a digital elevation model and various thematic maps. To identify the most influential environmental factors contributing to woodland recovery, binary logistic regression and linear regression techniques were applied. The analyses showed that although a large proportion of the P. brutia woodland has recovered 26 years after the fire event, a considerable amount of woodland had turned into scrub vegetation. Altitude, slope inclination, solar radiation, and pre-fire woodland physiognomy were identified as dominant factors influencing the vegetation’s recovery probability. Additionally, altitude and inclination are the variables that explain changes in the satellite remote sensing vegetation indices reflecting the recovery potential. Pinus brutia showed a good post-fire recovery potential, especially in parts of the study area with increased moisture availability.
de Leeuw, Jan; Georgiadou, P.Y.; Georgiadou, Yola; Kerle, Norman; de Gier, Alfred; Inoue, Yoshio; Ferwerda, Jelle; Smies, Maarten; Narantuya, Davaa
Limited awareness of environmental remote sensing’s potential ability to support environmental policy development constrains the technology’s utilization. This paper reviews the potential of earth observation from the perspective of environmental policy. A literature review of “remote sensing and policy” revealed that while the number of publications in this field increased almost twice as rapidly as that of remote sensing literature as a whole (15.3 versus 8.8% yr−1), there is apparently lit...
/geography, civil government, and have provided for appropriate measures for monitoring and compliance. This approach provides a valuable framework for companies, investors, customers, and foreign partners. The clearly-defined ground rules are designed to facilitate full private sector competition, innovation, and domestic and international market development. International market development remains a key issue for the U.S. Government and for U.S. industry in general. NOAA has learned of some interest by foreign governments in promulgating new laws and regulations to address this growing industry. However, to date, most governments have yet to publicize new commercial remote sensing laws or regulations. In some instances, data policies for commercial remote sensing have been developed, but only in the context of government-owned and operated systems, or private systems in which a government is the controlling shareholder. Other than some initial consultations and limited agreements between supplier nations, there has to date been little overall international coordination of commercial remote sensing policies and practices. The result has been an uncertain and non- uniform international business environment, which can cause difficulties for all commercial remote sensing operators. Related international market distortions inhibit the maturation of the industry and the normalization of business practices. This situation may make it more difficult for key stakeholders to make decisions on investments, purchases, regulatory affairs, and international partnerships. To put this growing industry on a more level footing, there should be further coordination
Mishra, Deepak R.
Tropical marine benthic habitats such as coral reef and associated environments are severely endangered because of the environmental degradation coupled with hurricanes, El Nino events, coastal pollution and runoff, tourism, and economic development. To monitor and protect this diverse environment it is important to not only develop baseline maps depicting their spatial distribution but also to document their changing conditions over time. Remote sensing offers an important means of delineating and monitoring coral reef ecosystems. Over the last twenty years the scientific community has been investigating the use and potential of remote sensing techniques to determine the conditions of the coral reefs by analyzing their spectral characteristics from space. One of the problems in monitoring coral reefs from space is the effect of the water column on the remotely sensed signal. When light penetrates water its intensity decreases exponentially with increasing depth. This process, known as water column attenuation, exerts a profound effect on remotely sensed data collected over water bodies. The approach presented in this research focuses on the development of semi-analytical models that resolves the confounding influence water column attenuation on substrate reflectance to characterize benthic habitats from high resolution remotely sensed imagery on a per-pixel basis. High spatial resolution satellite and airborne imagery were used as inputs in the models to derive water depth and water column optical properties (e.g., absorption and backscattering coefficients). These parameters were subsequently used in various bio-optical algorithms to deduce bottom albedo and then to classify the benthos, generating a detailed map of benthic habitats. IKONOS and QuickBird multispectral satellite data and AISA Eagle hyperspectral airborne data were used in this research for benthic habitat mapping along the north shore of Roatan Island, Honduras. The AISA Eagle classification was
Pedersen, Gro B. M.; Vilmundardóttir, Olga K.; Falco, Nicola; Sigurmundsson, Friðþór S.; Rustowicz, Rose; Belart, Joaquin M.-C.; Gísladóttir, Gudrun; Benediktsson, Jón A.
Iceland is exposed to rapid and dynamic landscape changes caused by natural processes and man-made activities, which impact and challenge the country. Fast and reliable mapping and monitoring techniques are needed on a big spatial scale. However, currently there is lack of operational advanced information processing techniques, which are needed for end-users to incorporate remote sensing (RS) data from multiple data sources. Hence, the full potential of the recent RS data explosion is not being fully exploited. The project Environmental Mapping and Monitoring of Iceland by Remote Sensing (EMMIRS) bridges the gap between advanced information processing capabilities and end-user mapping of the Icelandic environment. This is done by a multidisciplinary assessment of two selected remote sensing super sites, Hekla and Öræfajökull, which encompass many of the rapid natural and man-made landscape changes that Iceland is exposed to. An open-access benchmark repository of the two remote sensing supersites is under construction, providing high-resolution LIDAR topography and hyperspectral data for land-cover and landform classification. Furthermore, a multi-temporal and multi-source archive stretching back to 1945 allows a decadal evaluation of landscape and ecological changes for the two remote sensing super sites by the development of automated change detection techniques. The development of innovative pattern recognition and machine learning-based approaches to image classification and change detection is one of the main tasks of the EMMIRS project, aiming to extract and compute earth observation variables as automatically as possible. Ground reference data collected through a field campaign will be used to validate the implemented methods, which outputs are then inferred with geological and vegetation models. Here, preliminary results of an automatic land-cover classification based on hyperspectral image analysis are reported. Furthermore, the EMMIRS project
Christopher D. Lippitt; Douglas A. Stow; Philip J. Riggan
Remote sensing for hazard response requires a priori identification of sensor, transmission, processing, and distribution methods to permit the extraction of relevant information in timescales sufficient to allow managers to make a given time-sensitive decision. This study applies and demonstrates the utility of the Remote Sensing Communication...
Miller, L. D.; Tom, C.; Nualchawee, K.
A tropical forest area of Northern Thailand provided a test case of the application of the approach in more natural surroundings. Remote sensing imagery subjected to proper computer analysis has been shown to be a very useful means of collecting spatial data for the science of hydrology. Remote sensing products provide direct input to hydrologic models and practical data bases for planning large and small-scale hydrologic developments. Combining the available remote sensing imagery together with available map information in the landscape model provides a basis for substantial improvements in these applications.
Focardi, Silvia; Corsi, Ilaria; Mazzuoli, Stefania; Vignoli, Leonardo; Loiselle, Steven A; Focardi, Silvano
Aquatic ecosystems around the world, lake, estuaries and coastal areas are increasingly impacted by anthropogenic pollutants through different sources such as agricultural, industrial and urban discharges, atmospheric deposition and terrestrial drainage. Lake Victoria is the second largest lake in the world and the largest tropical lake. Bordered by Tanzania, Uganda, and Kenya, it provides a livelihood for millions of Africans in the region. However, the lake is under threat from eutrophication, a huge decline in the number of native fish species caused by several factors including loss of biodiversity, over fishing and pollution has been recently documented. Increasing usage of pesticides and insecticides in the adjacent agricultural areas as well as mercury contamination from processing of gold ore on the southern shores are currently considered among the most emergent phenomena of chemical contamination in the lake. By the application of globally consistent and comprehensive geospatial data-sets based on remote sensing integrated with information on heavy metals accumulation and insecticides exposure in native and alien fish populations, the present study aims at assessing the environmental risk associated to the contamination of the Lake Victoria water body on fish health, land cover distribution, biodiversity and the agricultural area surrounding the lake. By the elaboration of Landsat 7 TM data of November 2002 and Landsat 7 TM 1986 we have calculated the agriculture area which borders the Lake Victoria bay, which is an upland plain. The resulting enhanced nutrient loading to the soil is subsequently transported to the lake by rain or as dry fall. The data has been inserted in a Geographical information System (ARCGIS) to be upgraded and consulted. Heavy metals in fish fillets showed concentrations rather low except for mercury being higher than others as already described in previous investigations. In the same tissue, cholinesterases activity (ChE) as an
Prud'homme, Genevieve; Dobbin, Nina A.; Sun, Liu; Burnett, Richard T.; Martin, Randall V.; Davidson, Andrew; Cakmak, Sabit; Villeneuve, Paul J.; Lamsal, Lok N.; van Donkelaar, Aaron; Peters, Paul A.; Johnson, Markey
Satellite remote sensing (RS) has emerged as a cutting edge approach for estimating ground level ambient air pollution. Previous studies have reported a high correlation between ground level PM2.5 and NO2 estimated by RS and measurements collected at regulatory monitoring sites. The current study examined associations between air pollution and adverse respiratory and allergic health outcomes using multi-year averages of NO2 and PM2.5 from RS and from regulatory monitoring. RS estimates were derived using satellite measurements from OMI, MODIS, and MISR instruments. Regulatory monitoring data were obtained from Canada's National Air Pollution Surveillance Network. Self-reported prevalence of doctor-diagnosed asthma, current asthma, allergies, and chronic bronchitis were obtained from the Canadian Community Health Survey (a national sample of individuals 12 years of age and older). Multi-year ambient pollutant averages were assigned to each study participant based on their six digit postal code at the time of health survey, and were used as a marker for long-term exposure to air pollution. RS derived estimates of NO2 and PM2.5 were associated with 6-10% increases in respiratory and allergic health outcomes per interquartile range (3.97 μg m-3 for PM2.5 and 1.03 ppb for NO2) among adults (aged 20-64) in the national study population. Risk estimates for air pollution and respiratory/allergic health outcomes based on RS were similar to risk estimates based on regulatory monitoring for areas where regulatory monitoring data were available (within 40 km of a regulatory monitoring station). RS derived estimates of air pollution were also associated with adverse health outcomes among participants residing outside the catchment area of the regulatory monitoring network (p health among participants living outside the catchment area for regulatory monitoring suggest that RS can provide useful estimates of long-term ambient air pollution in epidemiologic studies. This is
The rapid growth of commercial remote sensing has made high quality digital sensing data widely available -- now, remote sensing must become and remain a strong, commercially viable industry. However, this new industry cannot survive without an educated consumer base. To access markets, remote sensing providers must make their product more accessible, both literally and figuratively: Potential customers must be able to find the data they require, when they require it, and they must understand the utility of the information available to them. The Internet and the World Wide Web offer the perfect medium to educate potential customers and to sell remote sensing data to those customers. A well-designed web presence can provide both an information center and a market place for companies offering their data for sale. A very high potential web-based market for remote sensing lies in media. News agencies, web sites, and a host of other visual media services can use remote sensing data to provide current, relevant information regarding news around the world. This paper will provide a model for promotion and sale of remote sensing data via the Internet.
Douglass, R. W.
A speech is given on operational remote sensing programs in forest management and the importance of remote sensing in forestry is emphasized. Forest service priorities in using remote sensing are outlined.
The overall objectives and strategies of the Center for Remote Sensing remain to provide a center for excellence for multidisciplinary scientific expertise to address land-related global habitability and earth observing systems scientific issues. Specific research projects that were underway during the final contract period include: digital classification of coniferous forest types in Michigan's northern lower peninsula; a physiographic ecosystem approach to remote classification and mapping; land surface change detection and inventory; analysis of radiant temperature data; and development of methodologies to assess possible impacts of man's changes of land surface on meteorological parameters. Significant progress in each of the five project areas has occurred. Summaries on each of the projects are provided.
Erkmen, Baris I.
This work relates to the generic problem of remote active imaging; that is, a source illuminates a target of interest and a receiver collects the scattered light off the target to obtain an image. Conventional imaging systems consist of an imaging lens and a high-resolution detector array [e.g., a CCD (charge coupled device) array] to register the image. However, conventional imaging systems for remote sensing require high-quality optics and need to support large detector arrays and associated electronics. This results in suboptimal size, weight, and power consumption. Computational ghost imaging (CGI) is a computational alternative to this traditional imaging concept that has a very simple receiver structure. In CGI, the transmitter illuminates the target with a modulated light source. A single-pixel (bucket) detector collects the scattered light. Then, via computation (i.e., postprocessing), the receiver can reconstruct the image using the knowledge of the modulation that was projected onto the target by the transmitter. This way, one can construct a very simple receiver that, in principle, requires no lens to image a target. Ghost imaging is a transverse imaging modality that has been receiving much attention owing to a rich interconnection of novel physical characteristics and novel signal processing algorithms suitable for active computational imaging. The original ghost imaging experiments consisted of two correlated optical beams traversing distinct paths and impinging on two spatially-separated photodetectors: one beam interacts with the target and then illuminates on a single-pixel (bucket) detector that provides no spatial resolution, whereas the other beam traverses an independent path and impinges on a high-resolution camera without any interaction with the target. The term ghost imaging was coined soon after the initial experiments were reported, to emphasize the fact that by cross-correlating two photocurrents, one generates an image of the target. In
P. L. N. Raju
Full Text Available One of the prime activities of Indian Space Research Organisation's (ISRO Space Program is providing satellite communication services, viz., television broadcasting, mobile communication, cyclone disaster warning and rescue operations etc. so as to improve their economic conditions, disseminate technical / scientific knowledge to improve the agriculture production and education for rural people of India. ISRO, along with National Aeronautical and Space Administration (NASA conducted experimental satellite communication project i.e. Satellite Instructional Television Experiment (SITE using NASA’s Advanced Telecommunication Satellite (i.e. ATS 6 with an objective to educate poor people of India via satellite broadcasting in 1975 and 1976, covering more than 2600 villages in six states of India and territories. Over the years India built communication satellites indigenously to meet the communication requirements of India. This has further lead to launch of an exclusive satellite from ISRO for educational purposes i.e. EDUSAT in 2004 through which rich audio-video content is transmitted / received, recreating virtual classes through interactivity. Indian Institute of Remote Sensing (IIRS established in 1966, a premier institute in south East Asia in disseminating Remote Sensing (RS and Geographical Information System (GIS, mainly focusing on contact based programs. But expanded the scope with satellite based Distance Learning Programs for Universities, utilizing the dedicated communication satellite i.e. EDUSAT in 2007. IIRS conducted successfully eight Distance Learning Programs in the last five years and training more than 6000 students mainly at postgraduate level from more than 60 universities /Institutions spread across India. IIRS obtained feedback and improved the programs on the continuous basis. Expanded the scope of IIRS outreach program to train user departments tailor made in any of the applications of Remote Sensing and
Rodriguez Lopez, Juan Miguel; Heider, Katharina; Scheffran, J?rgen
The data presented here were originally collected for the article “Frontiers of Urbanization: Identifying and Explaining Urbanization Hot Spots in the South of Mexico City Using Human and Remote Sensing” (Rodriguez et al. 2017) . They were divided into three databases (remote sensing, human sensing, and census information), using a multi-method approach with the goal of analyzing the impact of urbanization on protected areas in southern Mexico City. The remote sensing database was prepared...
Full Text Available With the rapid development of remote sensing technology, the quantity and variety of remote sensing images are growing so quickly that proactive and personalized access to data has become an inevitable trend. One of the active approaches is remote sensing image recommendation, which can offer related image products to users according to their preference. Although multiple studies on remote sensing retrieval and recommendation have been performed, most of these studies model the user profiles only from the perspective of spatial area or image features. In this paper, we propose a spatiotemporal recommendation method for remote sensing data based on the probabilistic latent topic model, which is named the Space-Time Periodic Task model (STPT. User retrieval behaviors of remote sensing images are represented as mixtures of latent tasks, which act as links between users and images. Each task is associated with the joint probability distribution of space, time and image characteristics. Meanwhile, the von Mises distribution is introduced to fit the distribution of tasks over time. Then, we adopt Gibbs sampling to learn the random variables and parameters and present the inference algorithm for our model. Experiments show that the proposed STPT model can improve the capability and efficiency of remote sensing image data services.
Albrecht, F.; Blaschke, T.; Lang, S.; Abdulmutalib, H. M.; Szabó, G.; Barsi, Á.; Batini, C.; Bartsch, A.; Kugler, Zs.; Tiede, D.; Huang, G.
The availability and accessibility of remote sensing (RS) data, cloud processing platforms and provided information products and services has increased the size and diversity of the RS user community. This development also generates a need for validation approaches to assess data quality. Validation approaches employ quality criteria in their assessment. Data Quality (DQ) dimensions as the basis for quality criteria have been deeply investigated in the database area and in the remote sensing domain. Several standards exist within the RS domain but a general classification - established for databases - has been adapted only recently. For an easier identification of research opportunities, a better understanding is required how quality criteria are employed in the RS lifecycle. Therefore, this research investigates how quality criteria support decisions that guide the RS lifecycle and how they relate to the measured DQ dimensions. Subsequently follows an overview of the relevant standards in the RS domain that is matched to the RS lifecycle. Conclusively, the required research needs are identified that would enable a complete understanding of the interrelationships between the RS lifecycle, the data sources and the DQ dimensions, an understanding that would be very valuable for designing validation approaches in RS.
IACOB I. CIPRIAN
Full Text Available Fractal Dimension of Urban Expansion Based on Remote Sensing Images: In Cluj-Napoca city the process of urbanization has been accelerated during the years and implication of local authorities reflects a relevant planning policy. A good urban planning framework should take into account the society demands and also it should satisfy the natural conditions of local environment. The expansion of antropic areas it can be approached by implication of 5D variables (time as a sequence of stages, space: with x, y, z and magnitude of phenomena into the process, which will allow us to analyse and extract the roughness of city shape. Thus, to improve the decision factor we take a different approach in this paper, looking at geometry and scale composition. Using the remote sensing (RS and GIS techniques we manage to extract a sequence of built-up areas (from 1980 to 2012 and used the result as an input for modelling the spatialtemporal changes of urban expansion and fractal theory to analysed the geometric features. Taking the time as a parameter we can observe behaviour and changes in urban landscape, this condition have been known as self-organized – a condition which in first stage the system was without any turbulence (before the antropic factor and during the time tend to approach chaotic behaviour (entropy state without causing an disequilibrium in the main system.
Full Text Available Remote sensing technologies have been widely applied in urban environments’ monitoring, synthesis and modeling. Incorporating spatial information in perceptually coherent regions, superpixel-based approaches can effectively eliminate the “salt and pepper” phenomenon which is common in pixel-wise approaches. Compared with fixed-size windows, superpixels have adaptive sizes and shapes for different spatial structures. Moreover, superpixel-based algorithms can significantly improve computational efficiency owing to the greatly reduced number of image primitives. Hence, the superpixel algorithm, as a preprocessing technique, is more and more popularly used in remote sensing and many other fields. In this paper, we propose a superpixel segmentation algorithm called Superpixel Segmentation with Local Competition (SSLC, which utilizes a local competition mechanism to construct energy terms and label pixels. The local competition mechanism leads to energy terms locality and relativity, and thus, the proposed algorithm is less sensitive to the diversity of image content and scene layout. Consequently, SSLC could achieve consistent performance in different image regions. In addition, the Probability Density Function (PDF, which is estimated by Kernel Density Estimation (KDE with the Gaussian kernel, is introduced to describe the color distribution of superpixels as a more sophisticated and accurate measure. To reduce computational complexity, a boundary optimization framework is introduced to only handle boundary pixels instead of the whole image. We conduct experiments to benchmark the proposed algorithm with the other state-of-the-art ones on the Berkeley Segmentation Dataset (BSD and remote sensing images. Results demonstrate that the SSLC algorithm yields the best overall performance, while the computation time-efficiency is still competitive.
Liu, Jiayin; Tang, Zhenmin; Cui, Ying; Wu, Guoxing
Remote sensing technologies have been widely applied in urban environments' monitoring, synthesis and modeling. Incorporating spatial information in perceptually coherent regions, superpixel-based approaches can effectively eliminate the "salt and pepper" phenomenon which is common in pixel-wise approaches. Compared with fixed-size windows, superpixels have adaptive sizes and shapes for different spatial structures. Moreover, superpixel-based algorithms can significantly improve computational efficiency owing to the greatly reduced number of image primitives. Hence, the superpixel algorithm, as a preprocessing technique, is more and more popularly used in remote sensing and many other fields. In this paper, we propose a superpixel segmentation algorithm called Superpixel Segmentation with Local Competition (SSLC), which utilizes a local competition mechanism to construct energy terms and label pixels. The local competition mechanism leads to energy terms locality and relativity, and thus, the proposed algorithm is less sensitive to the diversity of image content and scene layout. Consequently, SSLC could achieve consistent performance in different image regions. In addition, the Probability Density Function (PDF), which is estimated by Kernel Density Estimation (KDE) with the Gaussian kernel, is introduced to describe the color distribution of superpixels as a more sophisticated and accurate measure. To reduce computational complexity, a boundary optimization framework is introduced to only handle boundary pixels instead of the whole image. We conduct experiments to benchmark the proposed algorithm with the other state-of-the-art ones on the Berkeley Segmentation Dataset (BSD) and remote sensing images. Results demonstrate that the SSLC algorithm yields the best overall performance, while the computation time-efficiency is still competitive.
Mumby, Peter J.; Skirving, William; Strong, Alan E.; Hardy, John T.; LeDrew, Ellsworth F.; Hochberg, Eric J.; Stumpf, Rick P.; David, Laura T.
There has been a vast improvement in access to remotely sensed data in just a few recent years. This revolution of information is the result of heavy investment in new technology by governments and industry, rapid developments in computing power and storage, and easy dissemination of data over the internet. Today, remotely sensed data are available to virtually anyone with a desktop computer. Here, we review the status of one of the most popular areas of marine remote sensing research: coral reefs. Previous reviews have focused on the ability of remote sensing to map the structure and habitat composition of coral reefs, but have neglected to consider the physical environment in which reefs occur. We provide a holistic review of what can, might, and cannot be mapped using remote sensing at this time. We cover aspects of reef structure and health but also discuss the diversity of physical environmental data such as temperature, winds, solar radiation and water quality. There have been numerous recent advances in the remote sensing of reefs and we hope that this paper enhances awareness of the diverse data sources available, and helps practitioners identify realistic objectives for remote sensing in coral reef areas
Mumby, Peter J.; Skirving, William; Strong, Alan E.; Hardy, John T.; LeDrew, Ellsworth F.; Hochberg, Eric J.; Stumpf, Rick P.; David, Laura T
There has been a vast improvement in access to remotely sensed data in just a few recent years. This revolution of information is the result of heavy investment in new technology by governments and industry, rapid developments in computing power and storage, and easy dissemination of data over the internet. Today, remotely sensed data are available to virtually anyone with a desktop computer. Here, we review the status of one of the most popular areas of marine remote sensing research: coral reefs. Previous reviews have focused on the ability of remote sensing to map the structure and habitat composition of coral reefs, but have neglected to consider the physical environment in which reefs occur. We provide a holistic review of what can, might, and cannot be mapped using remote sensing at this time. We cover aspects of reef structure and health but also discuss the diversity of physical environmental data such as temperature, winds, solar radiation and water quality. There have been numerous recent advances in the remote sensing of reefs and we hope that this paper enhances awareness of the diverse data sources available, and helps practitioners identify realistic objectives for remote sensing in coral reef areas.
Fingas, Merv; Brown, Carl E
The technical aspects of oil spill remote sensing are examined and the practical uses and drawbacks of each technology are given with a focus on unfolding technology. The use of visible techniques is ubiquitous, but limited to certain observational conditions and simple applications. Infrared cameras offer some potential as oil spill sensors but have several limitations. Both techniques, although limited in capability, are widely used because of their increasing economy. The laser fluorosensor uniquely detects oil on substrates that include shoreline, water, soil, plants, ice, and snow. New commercial units have come out in the last few years. Radar detects calm areas on water and thus oil on water, because oil will reduce capillary waves on a water surface given moderate winds. Radar provides a unique option for wide area surveillance, all day or night and rainy/cloudy weather. Satellite-carried radars with their frequent overpass and high spatial resolution make these day-night and all-weather sensors essential for delineating both large spills and monitoring ship and platform oil discharges. Most strategic oil spill mapping is now being carried out using radar. Slick thickness measurements have been sought for many years. The operative technique at this time is the passive microwave. New techniques for calibration and verification have made these instruments more reliable.
Remote sensing techniques developed for exploration programs can often be used to address environmental issues facing the petroleum industry. While this industry becomes increasingly more environmentally conscious, budgets remain tight, requiring any technology used in environmental applications to be cost effective, widely available and reliable. In this paper a three-fold analysis of environmental issues facing the petroleum industry concludes: major areas of concern included environmental mapping natural habitats, surface cover, change through time, pollution monitoring (hazardous wastes, oil seeps and spills on and offshore), earth hazards assessment, baseline studies, facilities sitting and crisis response. options matrices were developed plotting current and near future RS technology vs environmental concerns, and each sensor/platform combination subjectively evaluated to determine which combination could best address the problem. While presently available RS technology (both airborne and spaceborne) has significant capability toward environmental mapping, hazards detection and other concerns, the anticipated launches of ERS-1, JERS-1, Landsat-6 and other systems will provide environmentally useful data available today only from relatively expensive and local airborne surveys. Low altitude airborne surveys and ground/sea truth will continue to be critical to any quantitative studies
I utilized state the art remote sensing and GIS (Geographical Information System) techniques to study large scale biological, physical and ecological processes of coastal, nearshore, and offshore waters of Lake Michigan and Lake Superior. These processes ranged from chlorophyll alpha and primary production time series analysies in Lake Michigan to coastal stamp sand threats on Buffalo Reef in Lake Superior. I used SeaWiFS (Sea-viewing Wide Field-of-view Sensor) satellite imagery to trace various biological, chemical and optical water properties of Lake Michigan during the past decade and to investigate the collapse of early spring primary production. Using spatial analysis techniques, I was able to connect these changes to some important biological processes of the lake (quagga mussels filtration). In a separate study on Lake Superior, using LiDAR (Light Detection and Ranging) and aerial photos, we examined natural coastal erosion in Grand Traverse Bay, Michigan, and discussed a variety of geological features that influence general sediment accumulation patterns and interactions with migrating tailings from legacy mining. These sediments are moving southwesterly towards Buffalo Reef, creating a threat to the lake trout and lake whitefish breeding ground.
Gudu, B R; Bi, H Y; Wang, H Y; Qin, S X; Ma, J W
In this paper, an airborne remote sensing data assimilation system for China Airborne Remote Sensing System is introduced. This data assimilation system is composed of a land surface model, data assimilation algorithms, observation data and fundamental parameters forcing the land surface model. In this data assimilation system, Variable Infiltration Capacity hydrologic model is selected as the land surface model, which also serves as the main framework of the system. Three-dimensional variation algorithm, four-dimensional variation algorithms, ensemble Kalman filter and Particle filter algorithms are integrated in this system. Observation data includes ground observations and remotely sensed data. The fundamental forcing parameters include soil parameters, vegetation parameters and the meteorological data
Qin Kai; Zhao Yingjun; Lu Donghua; Zhang Donghui; Wu Wenhuan
In this thesis, the author explored multi-source management problems of remote sensing data. The main idea is to use the mosaic dataset model, and the ways of an integreted display of image and its interpretation. Based on ArcGIS and IMINT feature knowledge platform, the author used the C# and other programming tools for development work, so as to design and implement multi-source remote sensing data management system function module which is able to simply, conveniently and efficiently manage multi-source remote sensing data. (authors)
Brost, Randolph; Perkins, David Nikolaus
Various technologies pertaining to identifying objects of interest in remote sensing images by searching over geospatial-temporal graph representations are described herein. Graphs are constructed by representing objects in remote sensing images as nodes, and connecting nodes with undirected edges representing either distance or adjacency relationships between objects and directed edges representing changes in time. Geospatial-temporal graph searches are made computationally efficient by taking advantage of characteristics of geospatial-temporal data in remote sensing images through the application of various graph search techniques.
Full Text Available For mapping, quantifying and monitoring regional and global forest health, satellite remote sensing provides fundamental data for the observation of spatial and temporal forest patterns and processes. While new remote-sensing technologies are able to detect forest data in high quality and large quantity, operational applications are still limited by deficits of in situ verification. In situ sampling data as input is required in order to add value to physical imaging remote sensing observations and possibilities to interlink the forest health assessment with biotic and abiotic factors. Numerous methods on how to link remote sensing and in situ data have been presented in the scientific literature using e.g. empirical and physical-based models. In situ data differs in type, quality and quantity between case studies. The irregular subsets of in situ data availability limit the exploitation of available satellite remote sensing data. To achieve a broad implementation of satellite remote sensing data in forest monitoring and management, a standardization of in situ data, workflows and products is essential and necessary for user acceptance. The key focus of the review is a discussion of concept and is designed to bridge gaps of understanding between forestry and remote sensing science community. Methodological approaches for in situ/remote-sensing implementation are organized and evaluated with respect to qualifying for forest monitoring. Research gaps and recommendations for standardization of remote-sensing based products are discussed. Concluding the importance of outstanding organizational work to provide a legally accepted framework for new information products in forestry are highlighted.
McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.
Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS.
McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.
Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS
Walter, Steven J.
Planetary spacecraft are viewed through a troposphere that absorbs and delays radio signals propagating through it. Tropospheric water, in the form of vapor, cloud liquid, and precipitation, emits radio noise which limits satellite telemetry communication link performance. Even at X-band, rain storms have severely affected several satellite experiments including a planetary encounter. The problem will worsen with DSN implementation of Ka-band because communication link budgets will be dominated by tropospheric conditions. Troposphere-induced propagation delays currently limit VLBI accuracy and are significant sources of error for Doppler tracking. Additionally, the success of radio science programs such as satellite gravity wave experiments and atmospheric occultation experiments depends on minimizing the effect of water vapor-induced propagation delays. In order to overcome limitations imposed by the troposphere, the Deep Space Network has supported a program of radiometric remote sensing. Currently, water vapor radiometers (WVRs) and microwave temperature profilers (MTPs) support many aspects of the Deep Space Network operations and research and development programs. Their capability to sense atmospheric water, microwave sky brightness, and atmospheric temperature is critical to development of Ka-band telemetry systems, communication link models, VLBI, satellite gravity wave experiments, and radio science missions. During 1993, WVRs provided data for propagation model development, supported planetary missions, and demonstrated advanced tracking capability. Collection of atmospheric statistics is necessary to model and predict performance of Ka-band telemetry links, antenna arrays, and radio science experiments. Since the spectrum of weather variations has power at very long time scales, atmospheric measurements have been requested for periods ranging from one year to a decade at each DSN site. The resulting database would provide reliable statistics on daily
Aug 31, 2017 ... to comprehend the tectonic development of the ... software for the analysis and interpretation of G– .... The application of remote sensing for mapping ..... Pf1 and Pf2 show profile locations adopted for joint G–M modelling.
remote sensing techniques particularly those referring to change detection. This kind of ... Technol. depending on many factors in relation to climate conditions, nature .... geomorphologic position make it a perfect wind corridor. (Chahbani ...
Ethiopian Journal of Environmental Studies and Management ... technology provides an efficient avenue of assessment of biomass content of any area. ... use data, can be integrated into GIS together with results from remote sensing analysis ...
Overview of remote sensing of chlorophyll flourescene in ocean waters. ... Besides empirical algorithms with the blue-green ratio, the algorithms based on ... between fluorescence and chlorophyll concentration and the red shift phenomena.
This comprehensive technical overview of the core theory of thermal remote sensing and its applications in hydrology, agriculture, and forestry includes a host of illuminating examples and covers everything from the basics to likely future trends in the field.
Jun 16, 2017 ... mainly focused on the models established by the remote sensing data in .... Page 5 of 16 58. Organization (WMO) World Weather Watch Pro- gram. ...... the disorder of urban sprawl would bring decreased vegetation cover and ...
Kunte, P.D.; Wagle, B.G.
Remote sensing data has been used for mapping coastal vegetation along the Goa Coast, India. The study envisages the use of digital image processing techniques for delineating geomorphic features and associated vegetation, including mangrove, along...
Houborg, Rasmus; Fisher, Joshua B.; Skidmore, Andrew K.
Remote sensing of vegetation function and traits has advanced significantly over the past half-century in the capacity to retrieve useful plant biochemical, physiological and structural quantities across a range of spatial and temporal scales
Singh, R.P.; Kumar, V.; Srivastav, S.K.
Soil-moisture interaction and the consequent liberation of ions causes the salinity of waters. The salinity of river, lake, ocean and ground water changes due to seepage and surface runoff. We have studied the feasibility of using microwave remote sensing for the estimation of salinity by carrying out numerical calculations to study the microwave remote sensing responses of various models representative of river, lake and ocean water. The results show the dependence of microwave remote sensing responses on the salinity and surface temperature of water. The results presented in this paper will be useful in the selection of microwave sensor parameters and in the accurate estimation of salinity from microwave remote sensing data
Prashad, L.; Christensen, P. R.; Anwar, S.; Dickenshied, S.; Engle, E.; Noss, D.
The ASU 100 Cities Project and the ASU Mars Space Flight Facility (MSFF) present JEarth, a set of analytical Geographic Information System (GIS) tools for viewing and processing Earth-based remote sensing imagery and vectors, including high-resolution and hyperspectral imagery such as TIMS and MASTER. JEarth is useful for a wide range of researchers and practitioners who need to access, view, and analyze remote sensing imagery. JEarth stems from existing MSFF applications: the Java application JMars (Java Mission-planning and Analysis for Remote Sensing) for viewing and analyzing remote sensing imagery and THMPROC, a web-based, interactive tool for processing imagery to create band combinations, stretches, and other imagery products. JEarth users can run the application on their desktops by installing Java-based open source software on Windows, Mac, or Linux operating systems.
.... This effort is cooperatively conducted with the professional researchers at the Remote Sensing GIS Center of the US Army Cold Regions Research and Engineering Laboratory in Hanover, New Hampshire...
The application of GMM to remote sensing image classification ... A . The boundary that has a Mahalanobis distance to the centre ... yields the Baye's theorem: ..... bands were extracted using the layer properties tool and visualised in MATLAB ...
Full Text Available Focused on the issue that conventional remote sensing image classification methods have run into the bottlenecks in accuracy, a new remote sensing image classification method inspired by deep learning is proposed, which is based on Stacked Denoising Autoencoder. First, the deep network model is built through the stacked layers of Denoising Autoencoder. Then, with noised input, the unsupervised Greedy layer-wise training algorithm is used to train each layer in turn for more robust expressing, characteristics are obtained in supervised learning by Back Propagation (BP neural network, and the whole network is optimized by error back propagation. Finally, Gaofen-1 satellite (GF-1 remote sensing data are used for evaluation, and the total accuracy and kappa accuracy reach 95.7% and 0.955, respectively, which are higher than that of the Support Vector Machine and Back Propagation neural network. The experiment results show that the proposed method can effectively improve the accuracy of remote sensing image classification.
National Aeronautics and Space Administration — The proposed innovation is Spark-RS, an open source software project that enables GPU-accelerated remote sensing workflows in an Apache Spark distributed computing...
Policelli, Frederick S.
Over the past 30 years, the scientific community has learned a great deal about the Earth as an integrated system. Much of this research has been enabled by the development of remote sensing technologies and their operation from space. Decision makers in many nations have begun to make use of remote sensing data for resource management, policy making, and sustainable development planning. This paper makes an attempt to provide a survey of the current state of the requirements and use of remote sensing for sustainable development in Africa. This activity has shown that there are not many climate data ready decision support tools already functioning in Africa. There are, however, endusers with known requirements who could benefit from remote sensing data.
Blending the most fundamental Remote-Sensing principles (RS) with the most functional spatial knowledge (GIS) with the objective of the determination of the accident-prone palms and points (case study: Tehran-Hamadan Highway on Saveh Superhighway)
Stanturf, J. A.; Heimbuch, D. G.
A refinement to the matrix approach to environmental impact assessment is to use landscape units in place of separate environmental elements in the analysis. Landscape units can be delineated by integrating remotely sensed data and available single-factor data. A remote sensing approach to landscape stratification is described and the conditions under which it is superior to other approaches that require single-factor maps are indicated. Flowcharts show the steps necessary to develop classification criteria, delineate units and a map legend, and use the landscape units in impact assessment. Application of the approach to assessing impacts of a transmission line in Montana is presented to illustrate the method.
Maynard, Nancy G.; Vicente, G. A.
In response to the need for improved observations of environmental factors to better understand the links between human health and the environment, NASA has established a new program to significantly improve the utilization of NASA's diverse array of data, information, and observations of the Earth for health applications. This initiative, lead by Goddard Space Flight Center (GSFC) has the following goals: (1) To encourage interdisciplinary research on the relationships between environmental parameters (e.g., rainfall, vegetation) and health, (2) Develop practical early warning systems, (3) Create a unique system for the exchange of Earth science and health data, (4) Provide an investigator field support system for customers and partners, (5) Facilitate a system for observation, identification, and surveillance of parameters relevant to environment and health issues. The NASA Environment and Health Program is conducting several interdisciplinary projects to examine applications of remote sensing data and information to a variety of health issues, including studies on malaria, Rift Valley Fever, St. Louis Encephalitis, Dengue Fever, Ebola, African Dust and health, meningitis, asthma, and filariasis. In addition, the NASA program is creating a user-friendly data system to help provide the public health community with easy and timely access to space-based environmental data for epidemiological studies. This NASA data system is being designed to bring land, atmosphere, water and ocean satellite data/products to users not familiar with satellite data/products, but who are knowledgeable in the Geographic Information Systems (GIS) environment. This paper discusses the most recent results of the interdisciplinary environment-health research projects and provides an analysis of the usefulness of the satellite data to epidemiological studies. In addition, there will be a summary of presently-available NASA Earth science data and a description of how it may be obtained.
Andrew A. Tronin
Full Text Available A wide range of satellite methods is applied now in seismology. The first applications of satellite data for earthquake exploration were initiated in the ‘70s, when active faults were mapped on satellite images. It was a pure and simple extrapolation of airphoto geological interpretation methods into space. The modern embodiment of this method is alignment analysis. Time series of alignments on the Earth's surface are investigated before and after the earthquake. A further application of satellite data in seismology is related with geophysical methods. Electromagnetic methods have about the same long history of application for seismology. Stable statistical estimations of ionosphere-lithosphere relation were obtained based on satellite ionozonds. The most successful current project "DEMETER" shows impressive results. Satellite thermal infra-red data were applied for earthquake research in the next step. Numerous results have confirmed previous observations of thermal anomalies on the Earth's surface prior to earthquakes. A modern trend is the application of the outgoing long-wave radiation for earthquake research. In ‘80s a new technology—satellite radar interferometry—opened a new page. Spectacular pictures of co-seismic deformations were presented. Current researches are moving in the direction of pre-earthquake deformation detection. GPS technology is also widely used in seismology both for ionosphere sounding and for ground movement detection. Satellite gravimetry has demonstrated its first very impressive results on the example of the catastrophic Indonesian earthquake in 2004. Relatively new applications of remote sensing for seismology as atmospheric sounding, gas observations, and cloud analysis are considered as possible candidates for applications.
Fylaktos, Asimakis; Yfantidou, Anastasia
Natural hazards like earthquakes can result to enormous property damage, and human casualties in mountainous areas. Italy has always been exposed to numerous earthquakes, mostly concentrated in central and southern regions. Last year, two seismic events near Norcia (central Italy) have occurred, which led to substantial loss of life and extensive damage to properties, infrastructure and cultural heritage. This research utilizes remote sensing products and GIS software, to provide a database of information. We used both SAR images of Sentinel 1A and optical imagery of Landsat 8 to examine the differences of topography with the aid of the multi temporal monitoring technique. This technique suits for the observation of any surface deformation. This database is a cluster of information regarding the consequences of the earthquakes in groups, such as property and infrastructure damage, regional rifts, cultivation loss, landslides and surface deformations amongst others, all mapped on GIS software. Relevant organizations can implement these data in order to calculate the financial impact of these types of earthquakes. In the future, we can enrich this database including more regions and enhance the variety of its applications. For instance, we could predict the future impacts of any type of earthquake in several areas, and design a preliminarily model of emergency for immediate evacuation and quick recovery response. It is important to know how the surface moves, in particular geographical regions like Italy, Cyprus and Greece, where earthquakes are so frequent. We are not able to predict earthquakes, but using data from this research, we may assess the damage that could be caused in the future.
Walsh, Brian M., E-mail: email@example.com [NASA Langley Research Center, Hampton, VA 23681 (United States); Lee, Hyung R. [National Institute of Aerospace, Hampton, VA 23666 (United States); Barnes, Norman P. [Science Systems and Applications, Inc., Hampton, VA 23666 (United States)
To accurately measure the concentrations of atmospheric gasses, especially the gasses with low concentrations, strong absorption features must be accessed. Each molecular species or constituent has characteristic mid-infrared absorption features by which either column content or range resolved concentrations can be measured. Because of these characteristic absorption features the mid infrared spectral region is known as the fingerprint region. However, as noted by the Decadal Survey, mid-infrared solid-state lasers needed for DIAL systems are not available. The primary reason is associated with short upper laser level lifetimes of mid infrared transitions. Energy gaps between the energy levels that produce mid-infrared laser transitions are small, promoting rapid nonradiative quenching. Nonradiative quenching is a multiphonon process, the more phonons needed, the smaller the effect. More low energy phonons are required to span an energy gap than high energy phonons. Thus, low energy phonon materials have less nonradiative quenching compared to high energy phonon materials. Common laser materials, such as oxides like YAG, are high phonon energy materials, while fluorides, chlorides and bromides are low phonon materials. Work at NASA Langley is focused on a systematic search for novel lanthanide-doped mid-infrared solid-state lasers using both quantum mechanical models (theoretical) and spectroscopy (experimental) techniques. Only the best candidates are chosen for laser studies. The capabilities of modeling materials, experimental challenges, material properties, spectroscopy, and prospects for lanthanide-doped mid-infrared solid-state laser devices will be presented. - Highlights: • We discuss mid infrared lasers and laser materials. • We discuss applications to remote sensing. • We survey the lanthanide ions in low phonon materials for potential. • We present examples of praseodymium mid infrared spectroscopy and laser design.
Strauss, Karl F.
This method enables sensing and quantization of analog strain gauges. By manufacturing a piezoelectric sensor stack in parallel (physical) with a piezoelectric actuator stack, the capacitance of the sensor stack varies in exact proportion to the exertion applied by the actuator stack. This, in turn, varies the output frequency of the local sensor oscillator. The output, F(sub out), is fed to a phase detector, which is driven by a stable reference, F(sub ref). The output of the phase detector is a square waveform, D(sub out), whose duty cycle, t(sub W), varies in exact proportion according to whether F(sub out) is higher or lower than F(sub ref). In this design, should F(sub out) be precisely equal to F(sub ref), then the waveform has an exact 50/50 duty cycle. The waveform, D(sub out), is of generally very low frequency suitable for safe transmission over long distances without corruption. The active portion of the waveform, t(sub W), gates a remotely located counter, which is driven by a stable oscillator (source) of such frequency as to give sufficient digitization of t(sub W) to the resolution required by the application. The advantage to this scheme is that it negates the most-common, present method of sending either very low level signals (viz. direct output from the sensors) across great distances (anything over one-half meter) or the need to transmit widely varying higher frequencies over significant distances thereby eliminating interference [both in terms of beat frequency generation and in-situ EMI (electromagnetic interference)] caused by ineffective shielding. It also results in a significant reduction in shielding mass.
van Diedenhoven, Bastiaan
Ice crystals in clouds exist in a virtually limitless variation of geometries. The most basic shapes of ice crystals are columnar or plate-like hexagonal prisms with aspect ratios determined by relative humidity and temperature. However, crystals in ice clouds generally display more complex structures owing to aggregation, riming and growth histories through varying temperature and humidity regimes. Crystal shape is relevant for cloud evolution as it affects microphysical properties such as fall speeds and aggregation efficiency. Furthermore, the scattering properties of ice crystals are affected by their general shape, as well as by microscopic features such as surface roughness, impurities and internal structure. To improve the representation of ice clouds in climate models, increased understanding of the global variation of crystal shape and how it relates to, e.g., location, cloud temperature and atmospheric state is crucial. Here, the remote sensing of ice crystal macroscale and microscale structure from airborne and space-based lidar depolarization observations and multi-directional measurements of total and polarized reflectances is reviewed. In addition, a brief overview is given of in situ and laboratory observations of ice crystal shape as well as the optical properties of ice crystals that serve as foundations for the remote sensing approaches. Lidar depolarization is generally found to increase with increasing cloud height and to vary with latitude. Although this variation is generally linked to the variation of ice crystal shape, the interpretation of the depolarization remains largely qualitative and more research is needed before quantitative conclusions about ice shape can be deduced. The angular variation of total and polarized reflectances of ice clouds has been analyzed by numerous studies in order to infer information about ice crystal shapes from them. From these studies it is apparent that pristine crystals with smooth surfaces are generally
Wardlow, Brian D.; Anderson, Martha C.; Sheffield, Justin; Doorn, Brad; Zhan, Xiwu; Rodell, Matt; Wardlow, Brian D.; Anderson, Martha C.; Verdin, James P.
The value of satellite remote sensing for drought monitoring was first realized more than two decades ago with the application of Normalized Difference Index (NDVI) data from the Advanced Very High Resolution Radiometer (AVHRR) for assessing the effect of drought on vegetation. Other indices such as the Vegetation Health Index (VHI) were also developed during this time period, and applied to AVHRR NDVI and brightness temperature data for routine global monitoring of drought conditions. These early efforts demonstrated the unique perspective that global imagers such as AVHRR could provide for operational drought monitoring through their near-daily, global observations of Earth's land surface. However, the advancement of satellite remote sensing of drought was limited by the relatively few spectral bands of operational global sensors such as AVHRR, along with a relatively short period of observational record. Remote sensing advancements are of paramount importance given the increasing demand for tools that can provide accurate, timely, and integrated information on drought conditions to facilitate proactive decision making (NIDIS, 2007). Satellite-based approaches are key to addressing significant gaps in the spatial and temporal coverage of current surface station instrument networks providing key moisture observations (e.g., rainfall, snow, soil moisture, ground water, and ET) over the United States and globally (NIDIS, 2007). Improved monitoring capabilities will be particularly important given increases in spatial extent, intensity, and duration of drought events observed in some regions of the world, as reported in the International Panel on Climate Change (IPCC) report (IPCC, 2007). The risk of drought is anticipated to further increase in some regions in response to climatic changes in the hydrologic cycle related to evaporation, precipitation, air temperature, and snow cover (Burke et al., 2006; IPCC, 2007; USGCRP, 2009). Numerous national, regional, and
Serafin, R. J.; Szejwach, G.; Phillips, B. B.
This paper explores the potential for airborne remote sensing for atmospheric sciences research. Passive and active techniques from the microwave to visible bands are discussed. It is concluded that technology has progressed sufficiently in several areas that the time is right to develop and operate new remote sensing instruments for use by the community of atmospheric scientists as general purpose tools. Promising candidates include Doppler radar and lidar, infrared short range radiometry, and microwave radiometry.
Full Text Available M B E R 2 0 0 8 15 USING REMOTELY- SENSED DATA FOR OPTIMAL FIELD SAMPLING BY DR PRAVESH DEBBA STATISTICS IS THE SCIENCE pertaining to the collection, summary, analysis, interpretation and presentation of data. It is often impractical... studies are: where to sample, what to sample and how many samples to obtain. Conventional sampling techniques are not always suitable in environmental studies and scientists have explored the use of remotely-sensed data as ancillary information to aid...
at reasonable logistical or financial costs . Remote sensing provides an attractive alternative. We discuss the range of different sensors that are...DARLA: Data Assimilation and Remote Sensing for Littoral Applications Final Report Award Number: N000141010932 Andrew T. Jessup Chris Chickadel...20. Radermacher, M., M. Wengrove, J. V. de Vries, and R. Holman (2014), Applicability of video-derived bathymetry estimates to nearshore current
Johannsen, Chris J.
The primary agricultural objective of this research is to determine what soil and crop information can be verified from remotely sensed images during the growing season. Specifically: (1) Elements of crop stress due to drought, weeds, disease and nutrient deficiencies will be documented with ground truth over specific agricultural sites and (2) Use of remote sensing with GPS and GIS technology for providing a safe and environmentally friendly application of fertilizers and chemicals will be documented.
Full Text Available Africa. 2Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Lynwood Road, Pretoria 0002, South Africa. 3Tshwane University of Technology, Pretoria 0001, South Africa. ABSTRACT A mobile LIDAR (LIght Detection... obtained using the CSIR-NLC mobile LIDAR in a 23 hour field campaign at the University of Pretoria. Index Terms— Atmospheric measurements, Remote sensing, Aerosols, Air pollution, Meteorology 1. INTRODUCTION Remote sensing is a technique...
In this chapter the author critically examines the prospects for reducing uncertainties over global biomass burning using remote sensing. First he considers the global temporal, spatial, and intensity distributions of fires and the remotely sensible signals they create and discusses the opportunities and problems that exist for matching available sensors to fire signal. Then he considers problems relating to instrumentation and to atmospheric interference
Roerink, G.J.; Wit, de A.J.W.; Pelgrum, H.; Mücher, C.A.
This report presents the results of the EU project "Carbon and water fluxes of Mediterranean forests and impacts of land use/cover changes". The objectives of the project can be summarized as follows: (I) surface energy balance mapping using remote sensing, (ii) carbon uptake mapping using remote
Terminology is a key issue for a better understanding among people using various languages. Terminology accuracy is essential during all phases of international cooperation. It is crucial to keep up with the latest quantitative and qualitative developments and novelties of the terminology in advanced technology fields such as aerospace science and industry. This is especially true in remote sensing and geoinformatics which develop rapidly and have wide and ever extending applications in various domains of human activity. The importance of the correct use of remote sensing terms refers not only to people working in this field but also to experts in many disciplines who handle remote sensing data and information products. The paper is devoted to terminology issues that refer to all aspects of remote sensing research and application areas. The attention is drawn on the recent needs and peculiarities of compiling specialized dictionaries in the subject area of remote sensing. Details are presented about the work in progress on the preparation of an English-Bulgarian dictionary of remote sensing terms focusing on Earth observations and geoinformation science. Our belief is that the elaboration of bilingual and multilingual dictionaries and glossaries in this spreading, most technically advanced and promising field of human expertise is of great practical importance. Any interest in cooperation and initiating of suchlike collaborative multilingual projects is welcome and highly appreciated.
Li, Zhaoqin; Xu, Dandan; Guo, Xulin
Maintaining a healthy ecosystem is essential for maximizing sustainable ecological services of the best quality to human beings. Ecological and conservation research has provided a strong scientific background on identifying ecological health indicators and correspondingly making effective conservation plans. At the same time, ecologists have asserted a strong need for spatially explicit and temporally effective ecosystem health assessments based on remote sensing data. Currently, remote sensing of ecosystem health is only based on one ecosystem attribute: vigor, organization, or resilience. However, an effective ecosystem health assessment should be a comprehensive and dynamic measurement of the three attributes. This paper reviews opportunities of remote sensing, including optical, radar, and LiDAR, for directly estimating indicators of the three ecosystem attributes, discusses the main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system, and provides some future perspectives. The main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system are: (1) scale issue; (2) transportability issue; (3) data availability; and (4) uncertainties in health indicators estimated from remote sensing data. However, the Radarsat-2 constellation, upcoming new optical sensors on Worldview-3 and Sentinel-2 satellites, and improved technologies for the acquisition and processing of hyperspectral, multi-angle optical, radar, and LiDAR data and multi-sensoral data fusion may partly address the current challenges.
Full Text Available Maintaining a healthy ecosystem is essential for maximizing sustainable ecological services of the best quality to human beings. Ecological and conservation research has provided a strong scientific background on identifying ecological health indicators and correspondingly making effective conservation plans. At the same time, ecologists have asserted a strong need for spatially explicit and temporally effective ecosystem health assessments based on remote sensing data. Currently, remote sensing of ecosystem health is only based on one ecosystem attribute: vigor, organization, or resilience. However, an effective ecosystem health assessment should be a comprehensive and dynamic measurement of the three attributes. This paper reviews opportunities of remote sensing, including optical, radar, and LiDAR, for directly estimating indicators of the three ecosystem attributes, discusses the main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system, and provides some future perspectives. The main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system are: (1 scale issue; (2 transportability issue; (3 data availability; and (4 uncertainties in health indicators estimated from remote sensing data. However, the Radarsat-2 constellation, upcoming new optical sensors on Worldview-3 and Sentinel-2 satellites, and improved technologies for the acquisition and processing of hyperspectral, multi-angle optical, radar, and LiDAR data and multi-sensoral data fusion may partly address the current challenges.
Ke-long Tan; Yu-qing Wan; Sun-xin Sun; Gui-bao Bao; Jing-shui Kuang [Aerophotogrammetry and Remote Sensing Center of China Coal, Xi' an (China)
In China it is important to explore coal prospecting by taking advantage of modern remote sensing and geographic information system technologies. Given a theoretical basis for coal prospecting by remote sensing, the methodologies and existing problems are demonstrated systematically by summarizing past practices of coal prospecting with remote sensing. A new theory of coal prospecting with remote sensing is proposed. In uncovered areas, coal resources can be prospected by direct interpretation. In coal bearing strata of developed areas covered by thin Quaternary strata or vegetation, prospecting for coal can be carried out by indirect interpretation of geomorphology and vegetation. For deeply buried underground deposits, coal prospecting can rely on tectonic structures, interpretation and analysis of new tectonic clues and regularity of coal formation and preservation controlled by tectonic structures. By applying newly hyper-spectral, multi-polarization, multi-angle, multi-temporal and multi-resolution remote sensing data and carrying out integrated analysis of geographic attributes, ground attributes, geophysical exploration results, geochemical exploration results, geological drilling results and remote sensing data by GIS tools, coal geology resources and mineralogical regularities can be explored and coal resource information can be acquired with some confidence. 12 refs., 4 figs., 3 tabs.
Li, Zhaoqin; Xu, Dandan; Guo, Xulin
Maintaining a healthy ecosystem is essential for maximizing sustainable ecological services of the best quality to human beings. Ecological and conservation research has provided a strong scientific background on identifying ecological health indicators and correspondingly making effective conservation plans. At the same time, ecologists have asserted a strong need for spatially explicit and temporally effective ecosystem health assessments based on remote sensing data. Currently, remote sensing of ecosystem health is only based on one ecosystem attribute: vigor, organization, or resilience. However, an effective ecosystem health assessment should be a comprehensive and dynamic measurement of the three attributes. This paper reviews opportunities of remote sensing, including optical, radar, and LiDAR, for directly estimating indicators of the three ecosystem attributes, discusses the main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system, and provides some future perspectives. The main challenges to develop a remote sensing-based spatially-explicit comprehensive ecosystem health system are: (1) scale issue; (2) transportability issue; (3) data availability; and (4) uncertainties in health indicators estimated from remote sensing data. However, the Radarsat-2 constellation, upcoming new optical sensors on Worldview-3 and Sentinel-2 satellites, and improved technologies for the acquisition and processing of hyperspectral, multi-angle optical, radar, and LiDAR data and multi-sensoral data fusion may partly address the current challenges. PMID:25386759
Moore, Gerald K.
Remote sensing is the use of electromagnetic energy to measure the physical properties of distant objects. It includes photography and geophysical surveying as well as newer techniques that use other parts of the electromagnetic spectrum. The history of remote sensing begins with photography. The origin of other types of remote sensing can be traced to World War II, with the development of radar, sonar, and thermal infrared detection systems. Since the 1960s, sensors have been designed to operate in virtually all of the electromagnetic spectrum. Today a wide variety of remote sensing instruments are available for use in hydrological studies; satellite data, such as Skylab photographs and Landsat images are particularly suitable for regional problems and studies. Planned future satellites will provide a ground resolution of 10–80 m. Remote sensing is currently used for hydrological applications in most countries of the world. The range of applications includes groundwater exploration determination of physical water quality, snowfield mapping, flood-inundation delineation, and making inventories of irrigated land. The use of remote sensing commonly results in considerable hydrological information at minimal cost. This information can be used to speed-up the development of water resources, to improve management practices, and to monitor environmental problems.
Selkowitz, David J.; Forster, Richard; Caldwell, Megan K.
Remote sensing of snow-covered area (SCA) can be binary (indicating the presence/absence of snow cover at each pixel) or fractional (indicating the fraction of each pixel covered by snow). Fractional SCA mapping provides more information than binary SCA, but is more difficult to implement and may not be feasible with all types of remote sensing data. The utility of fractional SCA mapping relative to binary SCA mapping varies with the intended application as well as by spatial resolution, temporal resolution and period of interest, and climate. We quantified the frequency of occurrence of partially snow-covered (mixed) pixels at spatial resolutions between 1 m and 500 m over five dates at two study areas in the western U.S., using 0.5 m binary SCA maps derived from high spatial resolution imagery aggregated to fractional SCA at coarser spatial resolutions. In addition, we used in situ monitoring to estimate the frequency of partially snow-covered conditions for the period September 2013–August 2014 at 10 60-m grid cell footprints at two study areas with continental snow climates. Results from the image analysis indicate that at 40 m, slightly above the nominal spatial resolution of Landsat, mixed pixels accounted for 25%–93% of total pixels, while at 500 m, the nominal spatial resolution of MODIS bands used for snow cover mapping, mixed pixels accounted for 67%–100% of total pixels. Mixed pixels occurred more commonly at the continental snow climate site than at the maritime snow climate site. The in situ data indicate that some snow cover was present between 186 and 303 days, and partial snow cover conditions occurred on 10%–98% of days with snow cover. Four sites remained partially snow-free throughout most of the winter and spring, while six sites were entirely snow covered throughout most or all of the winter and spring. Within 60 m grid cells, the late spring/summer transition from snow-covered to snow-free conditions lasted 17–56 days and averaged 37
Full Text Available Recently, hashing-based large-scale remote sensing (RS image retrieval has attracted much attention. Many new hashing algorithms have been developed and successfully applied to fast RS image retrieval tasks. However, there exists an important problem rarely addressed in the research literature of RS image hashing. The RS images are practically produced in a streaming manner in many real-world applications, which means the data distribution keeps changing over time. Most existing RS image hashing methods are batch-based models whose hash functions are learned once for all and kept fixed all the time. Therefore, the pre-trained hash functions might not fit the ever-growing new RS images. Moreover, the batch-based models have to load all the training images into memory for model learning, which consumes many computing and memory resources. To address the above deficiencies, we propose a new online hashing method, which learns and adapts its hashing functions with respect to the newly incoming RS images in terms of a novel online partial random learning scheme. Our hash model is updated in a sequential mode such that the representative power of the learned binary codes for RS images are improved accordingly. Moreover, benefiting from the online learning strategy, our proposed hashing approach is quite suitable for scalable real-world remote sensing image retrieval. Extensive experiments on two large-scale RS image databases under online setting demonstrated the efficacy and effectiveness of the proposed method.
Full Text Available The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.
Pohl, C.; Moellmann, J.; Fries, K.
The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment) in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS) to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR) and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.
Tang, Chia-Hsi; Coull, Brent A.; Schwartz, Joel; Lyapustin, Alexei I.; Di, Qian; Koutrakis, Petros
Information regarding the magnitude and distribution of PM(sub 2.5) emissions is crucial in establishing effective PM regulations and assessing the associated risk to human health and the ecosystem. At present, emission data is obtained from measured or estimated emission factors of various source types. Collecting such information for every known source is costly and time consuming. For this reason, emission inventories are reported periodically and unknown or smaller sources are often omitted or aggregated at large spatial scale. To address these limitations, we have developed and evaluated a novel method that uses remote sensing data to construct spatially-resolved emission inventories for PM(sub 2.5). This approach enables us to account for all sources within a fixed area, which renders source classification unnecessary. We applied this method to predict emissions in the northeast United States during the period of 2002-2013 using high- resolution 1 km x 1 km Aerosol Optical Depth (AOD). Emission estimates moderately agreed with the EPA National Emission Inventory (R(sup2) = 0.66 approx. 0.71, CV = 17.7 approx. 20%). Predicted emissions are found to correlate with land use parameters suggesting that our method can capture emissions from land use-related sources. In addition, we distinguished small-scale intra-urban variation in emissions reflecting distribution of metropolitan sources. In essence, this study demonstrates the great potential of remote sensing data to predict particle source emissions cost-effectively.
Many agricultural applications require spatially distributed information on growth-related crop characteristics that could be supplied through aircraft or satellite remote sensing. A study was conducted to develop and test a methodology for estimating plant canopy ground cover for cotton (Gossypium hirsutum L.) from scene reflectance. Previous studies indicated that a relatively simple relationship between ground cover and scene reflectance could be developed based on linear mixture modeling. Theoretical analysis indicated that the effects of shadows in the scene could be compensated for by averaging the results obtained using scene reflectance in the red and near-infrared wavelengths. The methodology was tested using field data collected over several years from cotton test plots in Texas and California. Results of the study appear to verify the utility of this approach. Since the methodology relies on information that can be obtained solely through remote sensing, it would be particularly useful in applications where other field information, such as plant size, row spacing, and row orientation, is unavailable
Full Text Available Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.
Xu, Dandan; Guo, Xulin
Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.
The increase in the number of operational Earth observation satellites gives remote sensing image fusion a new boost. As a powerful tool to integrate images from different sensors it enables multi-scale, multi-temporal and multi-source information extraction. Image fusion aims at providing results that cannot be obtained from a single data source alone. Instead it enables feature and information mining of higher reliability and availability. The process required to prepare remote sensing images for image fusion comprises most of the necessary steps to feed the database of Digital Earth. The virtual representation of the planet uses data and information that is referenced and corrected to suit interpretation and decision-making. The same pre-requisite is valid for image fusion, the outcome of which can directly flow into a geographical information system. The assessment and description of the quality of the results remains critical. Depending on the application and information to be extracted from multi-source images different approaches are necessary. This paper describes the process of image fusion based on a fusion and classification experiment, explains the necessary quality measures involved and shows with this example which criteria have to be considered if the results of image fusion are going to be used in Digital Earth
uxes, such as sensible heat ux, ground heat ux and net radiation, are also necessary. While it is possible to measure those uxes with ground-based instruments at local scales, at region scales they usually need to be modelled or estimated with the help of satellite remote sensing data. Even though...... to increase the spatial resolution of the reliable DTD-modelled fluxes from 1 km to 30 m. Furthermore, synergies between remote sensing based models and distributed hydrological models were studied with the aim of improving spatial performance of the hydrological models through incorporation of remote sensing...... of this study was to look at, and improve, various approaches for modelling the land-surface energy uxes at different spatial scales. The work was done using physically-based Two-Source Energy Balance (TSEB) approach as well as semi-empirical \\Triangle" approach. The TSEB-based approach was the main focus...
Full Text Available With the arrival of the big data era in Earth observation, the remote sensing communities have accumulated a large amount of invaluable and irreplaceable data for global monitoring. These massive remote sensing data have enabled large-area and long-term series Earth observation, and have, in particular, made standard, automated product generation more popular. However, there is more than one type of data selection for producing a certain remote sensing product; no single remote sensor can cover such a large area at one time. Therefore, we should automatically select the best data source from redundant multisource remote sensing data, or select substitute data if data is lacking, during the generation of remote sensing products. However, the current data selection strategy mainly adopts the empirical model, and has a lack of theoretical support and quantitative analysis. Hence, comprehensively considering the spectral characteristics of ground objects and spectra differences of each remote sensor, by means of spectrum simulation and correlation analysis, we propose a suitability evaluation model for product generation. The model will enable us to obtain the Production Suitability Index (PSI of each remote sensing data. In order to validate the proposed model, two typical value-added information products, NDVI and NDWI, and two similar or complementary remote sensors, Landsat-OLI and HJ1A-CCD1, were chosen, and the verification experiments were performed. Through qualitative and quantitative analysis, the experimental results were consistent with our model calculation results, and strongly proved the validity of the suitability evaluation model. The proposed production suitability evaluation model could assist with standard, automated, serialized product generation. It will play an important role in one-station, value-added information services during the big data era of Earth observation.
Doyle, S. E.
International cooperation in the U.S. Space Program is discussed and related to the NASA program for remote sensing of the earth. Satellite remote sensing techniques are considered along with the selection of the best sensors and wavelength bands. The technology of remote sensing satellites is considered with emphasis on the Landsat system configuration. Future aspects of remote sensing satellites are considered.
Colomina, Ismael; Molina, Pere
We discuss the evolution and state-of-the-art of the use of Unmanned Aerial Systems (UAS) in the field of Photogrammetry and Remote Sensing (PaRS). UAS, Remotely-Piloted Aerial Systems, Unmanned Aerial Vehicles or simply, drones are a hot topic comprising a diverse array of aspects including technology, privacy rights, safety and regulations, and even war and peace. Modern photogrammetry and remote sensing identified the potential of UAS-sourced imagery more than thirty years ago. In the last...
Academy of Natural Sciences, Philadelphia, PA.
This publication identifies some of the general concepts of remote sensing and explains the image collection process and computer-generated reconstruction of the data. Monitoring the ecological collapse in coral reefs, weather phenomena like El Nino/La Nina, and U.S. Space Shuttle-based sensing projects are some of the areas for which remote…
Carrino, Thais Andressa; Crósta, Alvaro Penteado; Toledo, Catarina Labouré Bemfica; Silva, Adalene Moreira
Remote sensing is a strategic key tool for mineral exploration, due to its capacity of detecting hydrothermal alteration minerals or alteration mineral zones associated with different types of mineralization systems. A case study of an epithermal system located in southern Peru is presented, aimed at the characterization of mineral assemblies for discriminating potential high sulfidation epithermal targets, using hyperspectral imagery integrated with petrography, XRD and magnetic data. HyMap images were processed using the Mixture Tuned Matched Filtering (MTMF) technique for producing alteration map in the Chapi Chiara epithermal gold prospect. Extensive areas marked by advanced argillic alteration (alunite-kaolinite-dickite ± topaz) were mapped in detail, as well as limited argillic (illite-smectite) and propylitic (chlorite spectral domain) alteration. The magmatic-hydrothermal processes responsible for the formation of hypogene minerals were also related to the destruction of ferrimagnetic minerals (e.g., magnetite) of host rocks such as andesite, and the remobilization/formation of paramagnetic Fe-Ti oxides (e.g., rutile, anatase). The large alteration zones of advanced argillic alteration are controlled by structures related to a regional NW-SE trend, and also by local NE-SW and ENE-WSW ones.
Yeo, I. Y.
We report the recent progress on our effort to improve the mapping of wetland dynamics and the modelling of its functioning and hydrological connection to the downstream waters. Our study focused on the Coastal Plain of the Chesapeake Bay Watershed (CBW), the Delmarva Peninsula, where the most of wetlands in CBW are densely distributed. The wetland ecosystem plays crucial roles in improving water quality and ecological integrity for the downstream waters and the Chesapeake Bay, and headwater wetlands in the region, such as Delmarva Bay, are now subject to the legal protection under the Clean Water Rules. We developed new wetland maps using time series Landsat images and a highly accurate LiDAR map over last 30 years. These maps show the changes in surface water fraction at a 30-m grid cell at annual time scale. Using GIS, we analyse these maps to characterize changing dynamics of wetland inundation due to the physical environmental factors (e.g., weather variability, tide) and assessed the hydrological connection of wetlands to the downstream water at the watershed scale. Focusing on the two adjacent watersheds in the upper region of the Choptank River Basin, we study how wetland inundation dynamics and the hydrologic linkage of wetlands to downstream water would vary by the local hydrogeological setting and attempt to identify the key landscape factors affecting the wetland ecosystems and functioning. We then discuss the potential of using remote sensing products to improve the physical modelling of wetlands from our experience with SWAT (Soil and Water Assessment Tool).
Chen, Chia-Ray; Hwang, Feng-Tai; Hsueh, Chuang-Wei
Revisiting time and global coverage are two major requirements for most of the remote sensing satellites. Constellation of satellites can get the benefit of short revisit time and global coverage. Typically, remote sensing satellites prefer to choose Sun Synchronous Orbit (SSO) because of fixed revisiting time and Sun beta angle. The system design and mission operation will be simple and straightforward. However, if we focus on providing remote sensing and store-and-forward communication services for low latitude countries, Sun Synchronous Orbit will not be the best choice because we need more satellites to cover the communication service gap in low latitude region. Sometimes the design drivers for remote sensing payloads are conflicted with the communication payloads. For example, lower orbit altitude is better for remote sensing payload performance, but the communication service zone will be smaller and we need more satellites to provide all time communication service. The current studies focus on how to provide remote sensing and communication services for low latitude countries. A cost effective approach for the mission, i.e. constellation of microsatellites, will be evaluated in this paper.
Senf, Cornelius; Seidl, Rupert; Hostert, Patrick
Insect disturbance are important agents of change in forest ecosystems around the globe, yet their spatial and temporal distribution and dynamics are not well understood. Remote sensing has gained much attention in mapping and understanding insect outbreak dynamics. Consequently, we here review the current literature on the remote sensing of insect disturbances. We suggest to group studies into three insect types: bark beetles, broadleaved defoliators, and coniferous defoliators. By so doing, we systematically compare the sensors and methods used for mapping insect disturbances within and across insect types. Results suggest that there are substantial differences between methods used for mapping bark beetles and defoliators, and between methods used for mapping broadleaved and coniferous defoliators. Following from this, we highlight approaches that are particularly suited for each insect type. Finally, we conclude by highlighting future research directions for remote sensing of insect disturbances. In particular, we suggest to: 1) Separate insect disturbances from other agents; 2) Extend the spatial and temporal domain of analysis; 3) Make use of dense time series; 4) Operationalize near-real time monitoring of insect disturbances; 5) Identify insect disturbances in the context of coupled human-natural systems; and 6) Improve reference data for assessing insect disturbances. Since the remote sensing of insect disturbances has gained much interest beyond the remote sensing community recently, the future developments identified here will help integrating remote sensing products into operational forest management. Furthermore, an improved spatiotemporal quantification of insect disturbances will support an inclusion of these processes into regional to global ecosystem models.
Walter, S. H. G.; Gasselt, S. V.; Michael, G.; Neukum, G.
The geometric outline of remote sensing image data, the so called footprint, can be represented as a number of coordinate tuples. These polygons are associated with according attribute information such as orbit name, ground- and image resolution, solar longitude and illumination conditions to generate a powerful base for classification of planetary experiment data. Speed, handling and extended capabilites are the reasons for using geodatabases to store and access these data types. Techniques for such a spatial database of footprint data are demonstrated using the Relational Database Management System (RDBMS) PostgreSQL, spatially enabled by the PostGIS extension. Exemplary, footprints of the HRSC and OMEGA instruments, both onboard ESA's Mars Express Orbiter, are generated and connected to attribute information. The aim is to provide high-resolution footprints of the OMEGA instrument to the science community for the first time and make them available for web-based mapping applications like the "Planetary Interactive GIS-on-the-Web Analyzable Database" (PIG- WAD), produced by the USGS. Map overlays with HRSC or other instruments like MOC and THEMIS (footprint maps are already available for these instruments and can be integrated into the database) allow on-the-fly intersection and comparison as well as extended statistics of the data. Footprint polygons are generated one by one using standard software provided by the instrument teams. Attribute data is calculated and stored together with the geometric information. In the case of HRSC, the coordinates of the footprints are already available in the VICAR label of each image file. Using the VICAR RTL and PostgreSQL's libpq C library they are loaded into the database using the Well-Known Text (WKT) notation by the Open Geospatial Consortium, Inc. (OGC). For the OMEGA instrument, image data is read using IDL routines developed and distributed by the OMEGA team. Image outlines are exported together with relevant attribute
van der Meer, Freek D.; van der Werff, Harald M. A.; van Ruitenbeek, Frank J. A.; Hecker, Chris A.; Bakker, Wim H.; Noomen, Marleen F.; van der Meijde, Mark; Carranza, E. John M.; Smeth, J. Boudewijn de; Woldai, Tsehaie
Geologists have used remote sensing data since the advent of the technology for regional mapping, structural interpretation and to aid in prospecting for ores and hydrocarbons. This paper provides a review of multispectral and hyperspectral remote sensing data, products and applications in geology. During the early days of Landsat Multispectral scanner and Thematic Mapper, geologists developed band ratio techniques and selective principal component analysis to produce iron oxide and hydroxyl images that could be related to hydrothermal alteration. The advent of the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) with six channels in the shortwave infrared and five channels in the thermal region allowed to produce qualitative surface mineral maps of clay minerals (kaolinite, illite), sulfate minerals (alunite), carbonate minerals (calcite, dolomite), iron oxides (hematite, goethite), and silica (quartz) which allowed to map alteration facies (propylitic, argillic etc.). The step toward quantitative and validated (subpixel) surface mineralogic mapping was made with the advent of high spectral resolution hyperspectral remote sensing. This led to a wealth of techniques to match image pixel spectra to library and field spectra and to unravel mixed pixel spectra to pure endmember spectra to derive subpixel surface compositional information. These products have found their way to the mining industry and are to a lesser extent taken up by the oil and gas sector. The main threat for geologic remote sensing lies in the lack of (satellite) data continuity. There is however a unique opportunity to develop standardized protocols leading to validated and reproducible products from satellite remote sensing for the geology community. By focusing on geologic mapping products such as mineral and lithologic maps, geochemistry, P-T paths, fluid pathways etc. the geologic remote sensing community can bridge the gap with the geosciences community. Increasingly
Henderson, Frederick B.
Since 1972, satellite remote sensing, when integrated with other exploration techniques, has demonstrated operational exploration and engineering cost savings and reduced exploration risks through improved geological mapping. Land and ocean remote sensing satellite systems under development for the 1990's by the United States, France, Japan, Canada, ESA, Russia, China, and others, will significantly increase our ability to explore for, develop, and manage energy and mineral resources worldwide. A major difference between these systems is the "Open Skies" and "Non-Discriminatory Access to Data" policies as have been practiced by the U.S. and France and the restrictive nationalistic data policies as have been practiced by Russia and India. Global exploration will use satellite remote sensing to better map regional structural and basin-like features that control the distribution of energy and mineral resources. Improved sensors will better map lithologic and stratigraphic units and identify alteration effects in rocks, soils, and vegetation cover indicative of undiscovered subsurface resources. These same sensors will also map and monitor resource development. The use of satellite remote sensing data will grow substantially through increasing integration with other geophysical, geochemical, and geologic data using improved geographic information systems (GIS). International exploration will focus on underdeveloped countries rather than on mature exploration areas such as the United States, Europe, and Japan. Energy and mineral companies and government agencies in these countries and others will utilize available remote sensing data to acquire economic intelligence on global resources. If the "Non-Discriminatory Access to Data" principle is observed by satellite producing countries, exploration will remain competitive "on the ground". In this manner, remote sensing technology will continue to be developed to better explore for and manage the world's needed resources
Garvin, J.B.; Schnetzler, C.; Grieve, R.A.F.
Geological remote sensing techniques can be used to investigate structural, depositional, and shock metamorphic effects associated with hypervelocity impact structures, some of which may be linked to global Earth system catastrophies. Although detailed laboratory and field investigations are necessary to establish conclusive evidence of an impact origin for suspected crater landforms, the synoptic perspective provided by various remote sensing systems can often serve as a pathfinder to key deposits which can then be targetted for intensive field study. In addition, remote sensing imagery can be used as a tool in the search for impact and other catastrophic explosion landforms on the basis of localized disruption and anomaly patterns. In order to reconstruct original dimensions of large, complex impact features in isolated, inaccessible regions, remote sensing imagery can be used to make preliminary estimates in the absence of field geophysical surveys. The experienced gained from two decades of planetary remote sensing of impact craters on the terrestrial planets, as well as the techniques developed for recognizing stages of degradation and initial crater morphology, can now be applied to the problem of discovering and studying eroded impact landforms on Earth. Preliminary results of remote sensing analyses of a set of terrestrial impact features in various states of degradation, geologic settings, and for a broad range of diameters and hence energies of formation are summarized. The intention is to develop a database of remote sensing signatures for catastrophic impact landforms which can then be used in EOS-era global surveys as the basis for locating the possibly hundreds of missing impact structures
Joseph, A.; Desa, E.
Acoustic techniques have become powerful tools for measurement of ocean circulation mainly because of the ability of acoustic signals to travel long distances in water, and the inherently non-invasive nature of measurement. The satellite remote...
Kimes, D. S.; Holben, B. N.; Tucker, C. J.; Newcomb, W. W.
The present investigation is concerned with the directional, off-nadir viewing of terrestrial scenes using remote-sensing systems from aircraft and satellite platforms, taking into account advantages of such an approach over strictly nadir viewing systems. Directional reflectance data collected for bare soil and several different vegetation canopies in NOAA-7 AVHRR bands 1 and 2 were analyzed. Optimum view angles were recommended for two strategies. The first strategy views the utility of off-nadir measurements as extending spatial and temporal coverage of the target area. The second strategy views the utility of off-nadir measurements as providing additional information about the physical characteristics of the target. Conclusions regarding the two strategies are discussed.
Gualtieri, J. Anthony; Cromp, R. F.
The Support Vector Machine provides a new way to design classification algorithms which learn from examples (supervised learning) and generalize when applied to new data. We demonstrate its success on a difficult classification problem from hyperspectral remote sensing, where we obtain performances of 96%, and 87% correct for a 4 class problem, and a 16 class problem respectively. These results are somewhat better than other recent results on the same data. A key feature of this classifier is its ability to use high-dimensional data without the usual recourse to a feature selection step to reduce the dimensionality of the data. For this application, this is important, as hyperspectral data consists of several hundred contiguous spectral channels for each exemplar. We provide an introduction to this new approach, and demonstrate its application to classification of an agriculture scene.
Gianinetto, Marco; Barazzetti, Luigi; Dini, Luigi; Fusiello, Andrea; Toldo, Roberto
The commercial market offers several software packages for the registration of remotely sensed data through standard one-to-one image matching. Although very rapid and simple, this strategy does not take into consideration all the interconnections among the images of a multi-temporal data set. This paper presents a new scientific software, called Satellite Automatic Multi-Image Registration (SAMIR), able to extend the traditional registration approach towards multi-image global processing. Tests carried out with high-resolution optical (IKONOS) and high-resolution radar (COSMO-SkyMed) data showed that SAMIR can improve the registration phase with a more rigorous and robust workflow without initial approximations, user's interaction or limitation in spatial/spectral data size. The validation highlighted a sub-pixel accuracy in image co-registration for the considered imaging technologies, including optical and radar imagery.
Ronald E. McRoberts; Brian F. Walters
Statistical inference requires expression of an estimate in probabilistic terms, usually in the form of a confidence interval. An approach to constructing confidence intervals for remote sensing-based estimates of net deforestation is illustrated. The approach is based on post-classification methods using two independent forest/non-forest classifications because...
Mogaji, Kehinde Anthony; Lim, Hwee San
This study integrates the application of Dempster-Shafer-driven evidential belief function (DS-EBF) methodology with remote sensing and geographic information system techniques to analyze surface and subsurface data sets for the spatial prediction of groundwater potential in Perak Province, Malaysia. The study used additional data obtained from the records of the groundwater yield rate of approximately 28 bore well locations. The processed surface and subsurface data produced sets of groundwater potential conditioning factors (GPCFs) from which multiple surface hydrologic and subsurface hydrogeologic parameter thematic maps were generated. The bore well location inventories were partitioned randomly into a ratio of 70% (19 wells) for model training to 30% (9 wells) for model testing. Application results of the DS-EBF relationship model algorithms of the surface- and subsurface-based GPCF thematic maps and the bore well locations produced two groundwater potential prediction (GPP) maps based on surface hydrologic and subsurface hydrogeologic characteristics which established that more than 60% of the study area falling within the moderate-high groundwater potential zones and less than 35% falling within the low potential zones. The estimated uncertainty values within the range of 0 to 17% for the predicted potential zones were quantified using the uncertainty algorithm of the model. The validation results of the GPP maps using relative operating characteristic curve method yielded 80 and 68% success rates and 89 and 53% prediction rates for the subsurface hydrogeologic factor (SUHF)- and surface hydrologic factor (SHF)-based GPP maps, respectively. The study results revealed that the SUHF-based GPP map accurately delineated groundwater potential zones better than the SHF-based GPP map. However, significant information on the low degree of uncertainty of the predicted potential zones established the suitability of the two GPP maps for future development of
Al Zayed, Islam Sabry; Elagib, Nadir Ahmed
This study proposes a novel monitoring tool based on Satellite Remote Sensing (SRS) data to examine the status of water distribution and Water Use Efficiency (WUE) under changing water policies in large-scale and complex irrigation schemes. The aim is to improve our understanding of the water-food nexus in such schemes. With a special reference to the Gezira Irrigation Scheme (GeIS) in Sudan during the period 2000-2014, the tool devised herein is well suited for cases where validation data are absent. First, it introduces an index, referred to as the Crop Water Consumption Index (CWCI), to assess the efficiency of water policies. The index is defined as the ratio of actual evapotranspiration (ETa) over agricultural areas to total ETa for the whole scheme where ETa is estimated using the Simplified Surface Energy Balance model (SSEB). Second, the tool uses integrated Normalized Difference Vegetation Index (iNDVI), as a proxy for crop productivity, and ETa to assess the WUE. Third, the tool uses SSEB ETa and NDVI in an attempt to detect wastage of water. Four key results emerged from this research as follows: 1) the WUE has not improved despite the changing agricultural and water policies, 2) the seasonal ETa can be used to detect the drier areas of GeIS, i.e. areas with poor irrigation water supply, 3) the decreasing trends of CWCI, slope of iNDVI-ETa linear regression and iNDVI are indicative of inefficient utilization of irrigation water in the scheme, and 4) it is possible to use SSEB ETa and NDVI to identify channels with spillover problems and detect wastage of rainwater that is not used as a source for irrigation. In conclusion, the innovative tool developed herein has provided important information on the efficiency of a large-scale irrigation scheme to help rationalize laborious water management processes and increase productivity.
Fan, Yaoshen; Chen, Shenliang; Zhao, Bo; Pan, Shunqi; Jiang, Chao; Ji, Hongyu
The Active Yellow River (Huanghe) Delta (AYRD) is a complex landform in which rapid deposition takes place due to its geologic formation and evolution. Continuous monitoring of shoreline dynamics at high-temporal frequency is crucial for understanding the processes and the driving factors behind this rapidly changing coast. Great efforts have been devoted to map the changing shoreline of the Yellow River delta and explain such changes through remote sensing data. However, the temporal frequency of shoreline in the obtained datasets are generally not fine enough to reflect the detailed or subtly variable processes of shoreline retreat and advance. To overcome these limitations, we continuously monitored the dynamics of this shoreline using time series of Landsat data based on tidal-level calibration model and orthogonal-transect method. The Abrupt Change Value (ACV) results indicated that the retreat-advance patterns had a significant impact regardless of season or year. The Water-Sediment Regulation Scheme (WSRS) plays a dominant role in delivering river sediment discharge to the sea and has an impact on the annual average maximum ACV, especially at the mouth of the river. The positive relationship among the average ACV, runoff and sediment load are relatively obvious; however, we found that the Relative Exposure Index (REI) that measures wave energy was able to explain only approximately 20% of the variation in the data. Based on the abrupt change at the shoreline of the AYRD, river flow and time, we developed a binary regression model to calculate the critical sediment load and water discharge for maintaining the equilibrium of the active delta from 2002 to 2015. These values were approximately 0.48 × 108 t/yr and 144.37 × 108 m3/yr. If the current water and sediment proportions released from the Xiaolangdi Reservoir during the WSRS remain stable, the erosion-accretion patterns of the active delta will shift from rapid accretion to a dynamic balance.
Jonckheere, Inge; Sandoval, Alberto
REDD, which stands for 'Reducing Emissions from Deforestation and Forest Degradation in Developing Countries' - is an effort to create a financial value for the carbon stored in forests, offering incentives for developing countries to reduce emissions from forested lands and invest in low-carbon paths to sustainable development. The UN-REDD Programme, a collaborative partnership between FAO, UNDP and UNEP launched in September 2008, supports countries to develop capacity to REDD and to implement a future REDD mechanism in a post- 2012 climate regime. The programme works at both the national and global scale, through support mechanisms for country-driven REDD strategies and international consensus-building on REDD processes. The UN-REDD Programme gathers technical teams from around the world to develop common approaches, analyses and guidelines on issues such as measurement, reporting and verification (MRV) of carbon emissions and flows, remote sensing, and greenhouse gas inventories. Within the partnership, FAO supports countries on technical issues related to forestry and the development of cost effective and credible MRV processes for emission reductions. While at the international level, it fosters improved guidance on MRV approaches, including consensus on principles and guidelines for MRV and training programmes.It provides guidance on how best to design and implement REDD, to ensure that forests continue to provide multiple benefits for livelihoods and biodiversity to societies while storing carbon at the same time. Other areas of work include national forest assessments and monitoring of in-country policy and institutional change. The outcomes about the role of satellite remote sensing technologies as a tool for monitoring, assessment, reporting and verification of carbon credits and co-benefits under the REDD mechanism are here presented.
Moreno, A.; Camps-Valls, G.; Carvalhais, N.; Kattge, J.; Robinson, N.; Reichstein, M.; Allred, B. W.; Running, S. W.
Wood density (WD) is defined as the oven-dry mass divided by fresh volume, varies between individuals, and describes the carbon investment per unit volume of stem. WD has been proven to be a key functional trait in carbon cycle research and correlates with numerous morphological, mechanical, physiological, and ecological properties. In spite of the utility and importance of this trait, there is a lack of an operational framework to spatialize plant WD measurements at a global scale. In this work, we present a consistent modular processing chain to derive global maps (500 m) of WD using modern machine learning techniques along with optical remote sensing data (MODIS/Landsat) and climate data using the Google Earth Engine platform. The developed approach uses a hierarchical Bayesian approach to fill in gaps in the plant measured WD data set to maximize its global representativeness. WD plant species are then aggregated to Plant Functional Types (PFT). The spatial abundance of PFT at 500 m spatial resolution (MODIS) is calculated using a high resolution (30 m) PFT map developed using Landsat data. Based on these PFT abundances, representative WD values are estimated for each MODIS pixel with nearby measured data. Finally, random forests are used to globally estimate WD from these MODIS pixels using remote sensing and climate. The validation and assessment of the applied methods indicate that the model explains more than 72% of the spatial variance of the calculated community aggregated WD estimates with virtually unbiased estimates and low RMSE (<15%). The maps thus offer new opportunities to study and analyze the global patterns of variation of WD at an unprecedented spatial coverage and spatial resolution.
Full Text Available China's long-term planning major projects "high-resolution earth observation system" has been invested nearly 100 billion and the satellites will reach 100 to 2020. As to 2/3 of China's area covered by mountains，it has a higher demand for remote sensing. In addition to light intensity, frequency, phase, polarization is also the main physical characteristics of remote sensing electromagnetic waves. Polarization is an important component of the reflected information from the surface and the atmospheric information, and the polarization effect of the ground object reflection is the basis of the observation of polarization remote sensing. Therefore, the effect of eliminating the polarization effect is very important for remote sensing applications. The main innovations of this paper is as follows: (1 Remote sensing observation method. It is theoretically deduced and verified that the polarization can weaken the light in the strong light region, and then provide the polarization effective information. In turn, the polarization in the low light region can strengthen the weak light, the same can be obtained polarization effective information. (2 Polarization effect of vegetation. By analyzing the structure characteristics of vegetation, polarization information is obtained, then the vegetation structure information directly affects the absorption of biochemical components of leaves. (3 Atmospheric polarization neutral point observation method. It is proved to be effective to achieve the ground-gas separation, which can achieve the effect of eliminating the atmospheric polarization effect and enhancing the polarization effect of the object.
Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton
Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941
Maria Laura Zoffoli
Full Text Available Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application.
Prasad S. Thenkabail
Full Text Available Remote Sensing, an open access journal (http://www.mdpi.com/journal/remotesensing has grown at rapid pace since its first publication five years ago, and has acquired a strong reputation. It is a “pathfinder” being the first open access journal in remote sensing. For those academics who were used to waiting a year or two for their peer-reviewed scientific work to be reviewed, revised, edited, and published, Remote Sensing offers a publication time frame that is unheard of (in most cases, less than four months. However, we do this after multiple peer-reviews, multiple revisions, much editorial scrutiny and decision-making, and professional editing by an editorial office before a paper is published online in our tight time frame, bringing a paradigm shift in scientific publication. As a result, there has been a swift increase in submissions of higher and higher quality manuscripts from the best authors and institutes working on Remote Sensing, Geographic Information Systems (GIS, Global Navigation Satellite System (GNSS, GIScience, and all related geospatial science and technologies from around the world. The purpose of this editorial is to update everyone interested in Remote Sensing on the progress made over the last year, and provide an outline of our vision for the immediate future. [...
Sun, Wei-Qi; Zhao, Yun-Sheng; Tu, Lin-Ling
In the present paper, the slope gradient, aspect, detection zenith angle and plant types were analyzed. In order to strengthen the theoretical discussion, the research was under laboratory condition, and modeled uniform slope for slope plant. Through experiments we found that these factors indeed have influence on plant hyperspectral remote sensing. When choosing slope gradient as the variate, the blade reflection first increases and then decreases as the slope gradient changes from 0° to 36°; When keeping other factors constant, and only detection zenith angle increasing from 0° to 60°, the spectral characteristic of slope plants do not change significantly in visible light band, but decreases gradually in near infrared band; With only slope aspect changing, when the dome meets the light direction, the blade reflectance gets maximum, and when the dome meets the backlit direction, the blade reflectance gets minimum, furthermore, setting the line of vertical intersection of incidence plane and the dome as an axis, the reflectance on the axis's both sides shows symmetric distribution; In addition, spectral curves of different plant types have a lot differences between each other, which means that the plant types also affect hyperspectral remote sensing results of slope plants. This research breaks through the limitations of the traditional vertical remote sensing data collection and uses the multi-angle and hyperspectral information to analyze spectral characteristics of slope plants. So this research has theoretical significance to the development of quantitative remote sensing, and has application value to the plant remote sensing monitoring.
Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton
Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application.
Full Text Available Remote sensing image registration plays an important role in military and civilian fields, such as natural disaster damage assessment, military damage assessment and ground targets identification, etc. However, due to the ground relief variations and imaging viewpoint changes, non-rigid geometric distortion occurs between remote sensing images with different viewpoint, which further increases the difficulty of remote sensing image registration. To address the problem, we propose a multi-viewpoint remote sensing image registration method which contains the following contributions. (i A multiple features based finite mixture model is constructed for dealing with different types of image features. (ii Three features are combined and substituted into the mixture model to form a feature complementation, i.e., the Euclidean distance and shape context are used to measure the similarity of geometric structure, and the SIFT (scale-invariant feature transform distance which is endowed with the intensity information is used to measure the scale space extrema. (iii To prevent the ill-posed problem, a geometric constraint term is introduced into the L2E-based energy function for better behaving the non-rigid transformation. We evaluated the performances of the proposed method by three series of remote sensing images obtained from the unmanned aerial vehicle (UAV and Google Earth, and compared with five state-of-the-art methods where our method shows the best alignments in most cases.
Griffith, J.A.; Egbert, S.L.
Remote sensing education is increasingly in demand across academic and professional disciplines. Meanwhile, Internet technology and the World Wide Web (WWW) are being more frequently employed as teaching tools in remote sensing and other disciplines. The current wealth of information on the Internet and World Wide Web must be distilled, nonetheless, to be useful in remote sensing education. An extensive literature base is developing on the WWW as a tool in education and in teaching remote sensing. This literature reveals benefits and limitations of the WWW, and can guide its implementation. Among the most beneficial aspects of the Web are increased access to remote sensing expertise regardless of geographic location, increased access to current material, and access to extensive archives of satellite imagery and aerial photography. As with other teaching innovations, using the WWW/Internet may well mean more work, not less, for teachers, at least at the stage of early adoption. Also, information posted on Web sites is not always accurate. Development stages of this technology range from on-line posting of syllabi and lecture notes to on-line laboratory exercises and animated landscape flyovers and on-line image processing. The advantages of WWW/Internet technology may likely outweigh the costs of implementing it as a teaching tool.
Innes, J.L.; Koch, B.
Several international conventions and agreements have stressed the importance of the assessment of forest biodiversity. However, the methods by which such assessments can be made remain unclear. Remote sensing represents an important tool for looking at ecosystem diversity and various structural aspects of individual ecosystems. It provides a means to make assessments across several different spatial scales, and is also critical for assessments of changes in ecosystem pattern over time. Many different forms of remote sensing are available. While lately the emphasis on laser scanner and synthetic aperture radar data has increased, most work to date has used photographs and digital optical imagery, primarily from airborne and spaceborne platforms. These provide the opportunity to assess different phenomena from the landscape to the stand scale. Remote sensing provides the most efficient tool available for determining landscape-scale elements of forest biodiversity, such as the relative proportion of matrix and patches and their physical arrangement. At intermediate scales, remote sensing provides an ideal tool for evaluating the presence of corridors and the nature of edges. At the stand scale, remote sensing technologies are likely to deliver an increasing amount of information about the structural attributes of forest stands, such as the nature of the canopy surface, the presence of layering within the canopy and presence of (very) coarse woody debris on the forest floor. Given the rate of development in the technology, even greater usage is likely in the future. (author)
Popov, M.; Fedorovsky, O.; Stankevich, S.; Filipovich, V.; Khyzhniak, A.; Piestova, I.; Lubskyi, M.; Svideniuk, M.
The approach to implementing the remote sensing technologies and geospatial modelling for smart city support is presented. The hierarchical structure and basic components of the smart city information support subsystem are considered. Some of the already available useful practical developments are described. These include city land use planning, urban vegetation analysis, thermal condition forecasting, geohazard detection, flooding risk assessment. Remote sensing data fusion approach for comprehensive geospatial analysis is discussed. Long-term city development forecasting by Forrester - Graham system dynamics model is provided over Kiev urban area.
Lees, K J; Quaife, T; Artz, R R E; Khomik, M; Clark, J M
Peatlands store large amounts of terrestrial carbon and any changes to their carbon balance could cause large changes in the greenhouse gas (GHG) balance of the Earth's atmosphere. There is still much uncertainty about how the GHG dynamics of peatlands are affected by climate and land use change. Current field-based methods of estimating annual carbon exchange between peatlands and the atmosphere include flux chambers and eddy covariance towers. However, remote sensing has several advantages over these traditional approaches in terms of cost, spatial coverage and accessibility to remote locations. In this paper, we outline the basic principles of using remote sensing to estimate ecosystem carbon fluxes and explain the range of satellite data available for such estimations, considering the indices and models developed to make use of the data. Past studies, which have used remote sensing data in comparison with ground-based calculations of carbon fluxes over Northern peatland landscapes, are discussed, as well as the challenges of working with remote sensing on peatlands. Finally, we suggest areas in need of future work on this topic. We conclude that the application of remote sensing to models of carbon fluxes is a viable research method over Northern peatlands but further work is needed to develop more comprehensive carbon cycle models and to improve the long-term reliability of models, particularly on peatland sites undergoing restoration. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Hashim, M; Pour, A B; Onn, C H
Remote sensing technology is an important tool to analyze vegetation dynamics, quantifying vegetation fraction of Earth's agricultural and natural vegetation. In optical remote sensing analysis removing atmospheric interferences, particularly distribution of cloud contaminations, are always a critical task in the tropical climate. This paper suggests a fast and alternative approach to remove cloud and shadow contaminations for Landsat Enhanced Thematic Mapper + (ETM + ) multi temporal datasets. Band 3 and Band 4 from all the Landsat ETM + dataset are two main spectral bands that are very crucial in this study for cloud removal technique. The Normalise difference vegetation index (NDVI) and the normalised difference soil index (NDSI) are two main derivatives derived from the datasets. Change vector analysis is used in this study to seek the vegetation dynamics. The approach developed in this study for cloud optimizing can be broadly applicable for optical remote sensing satellite data, which are seriously obscured with heavy cloud contamination in the tropical climate
Kittel, Cecile Marie Margaretha; Nielsen, Karina; Tøttrup, C.
with publicly available and free remote sensing observations. We used a rainfall–runoff model based on the Budyko framework coupled with a Muskingum routing approach. We parametrized the model using the Shuttle Radar Topography Mission digital elevation model (SRTM DEM) and forced it using precipitation from......Remote sensing provides a unique opportunity to inform and constrain a hydrological model and to increase its value as a decision-support tool. In this study, we applied a multi-mission approach to force, calibrate and validate a hydrological model of the ungauged Ogooué river basin in Africa...... model also captures overall total water storage change patterns, although the amplitude of storage change is generally underestimated. By combining hydrological modeling with multi-mission remote sensing from 10 different satellite missions, we obtain new information on an otherwise unstudied basin...
Ding, Peng; Zhang, Ye; Deng, Wei-Jian; Jia, Ping; Kuijper, Arjan
Detection of objects from satellite optical remote sensing images is very important for many commercial and governmental applications. With the development of deep convolutional neural networks (deep CNNs), the field of object detection has seen tremendous advances. Currently, objects in satellite remote sensing images can be detected using deep CNNs. In general, optical remote sensing images contain many dense and small objects, and the use of the original Faster Regional CNN framework does not yield a suitably high precision. Therefore, after careful analysis we adopt dense convoluted networks, a multi-scale representation and various combinations of improvement schemes to enhance the structure of the base VGG16-Net for improving the precision. We propose an approach to reduce the test-time (detection time) and memory requirements. To validate the effectiveness of our approach, we perform experiments using satellite remote sensing image datasets of aircraft and automobiles. The results show that the improved network structure can detect objects in satellite optical remote sensing images more accurately and efficiently.
Higg, H. C.; Butera, K. M.; Settle, M.
Research since the launch of LANDSAT-1 has been primarily directed to the development of analysis techniques and to the conduct of applications studies designed to address resource information needs in the United States and in many other countries. The current measurement capabilities represented by MSS, TM, and SIR-A and B, coupled with the present level of remote sensing understanding and the state of knowledge in the discipline earth sciences, form the foundation for NASA's Land Processes Program. Science issues to be systematically addressed include: energy balance, hydrologic cycle, biogeochemical cycles, biological productivity, rock cycle, landscape development, geological and botanical associations, and land surface inventory, monitoring, and modeling. A global perspective is required for using remote sensing technology for problem solving or applications context. A successful model for this kind of activity involves joint research with a user entity where the user provides a test site and ground truth and NASA provides the remote sensing techniques to be tested. | <urn:uuid:e1dde6dc-29db-4088-95c1-89497056f68c> | 2.6875 | 110,915 | Content Listing | Science & Tech. | 20.078341 | 95,488,729 |
This image shows one of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA's Mars Reconnaissance Orbiter since 2006.
The University of Arizona's High Resolution Imaging Science Experiment, or HiRISE camera, took pictures of the fresh craters at sites where before and after images had been taken. This combination provided a new way to make direct measurements of the impact rate on Mars and will lead to better age estimates of recent features on Mars, some of which may have been the result of climate change."It's exciting to find these new craters right after they form," said Ingrid Daubar of the UA, lead author of the paper published online this month by the journal Icarus. "It reminds you Mars is an active planet, and we can study processes that are happening today."
HiRISE targeted places where dark spots had appeared during the time between images taken by the spacecraft's Context Camera, or CTX, or cameras on other orbiters. The new estimate of cratering rate is based on a portion of the 248 new craters detected. If comes from a systematic check of a dusty fraction of the planet with CTX since late 2006.
The impacts disturb the dust, creating noticeable blast zones. In this part of the research, 44 fresh impact sites were identified.
The meteor over Chelyabinsk, Russia, in February was about 10 times bigger than the objects that dug the fresh Martian craters.
Estimates of the rate at which new craters appear serve as scientists' best yardstick for estimating the ages of exposed landscape surfaces on Mars and other worlds.
Daubar and co-authors calculated a rate for how frequently new craters at least 12.8 feet (3.9 meters) in diameter are excavated. The rate is equivalent to an average of one each year on each area of the Martian surface roughly the size of the U.S. state of Texas. Earlier estimates pegged the cratering rate at three to 10 times more craters per year. They were based on studies of craters on the moon and the ages of lunar rocks collected during NASA's Apollo missions in the late 1960s and early 1970s.
"Mars now has the best-known current rate of cratering in the solar system," said UA's HiRISE Principal Investigator Alfred McEwen, a co-author on the paper.
MRO has been examining Mars with six instruments since 2006. Daubar is an imaging targeting specialist who has been on the HiRISE uplink operation s team from the very beginning. She is also a graduate student in the UA's department of planetary science and plans on graduating with her doctorate in spring 2014.
"There are five of us who help plan the images that HiRISE will take over a two-week cycle," she explained. "We work with science team members across the world to understand their science goals, help select the image targets and compile the commands for the spacecraft and the camera."
"The longevity of this mission is providing wonderful opportunities for investigating changes on Mars," said MRO Deputy Project Scientist Leslie Tamppari of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The UA Lunar and Planetary Laboratory operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colo. Malin Space Science Systems of San Diego built and operates the Context Camera. JPL manages the MRO for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver, built the orbiter.
Daniel Stolte | University of Arizona
Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
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about this item
Catalysis is a fundamentally sustainable process which can be used to produce a wide range of chemicals and their intermediates. Focussing on those catalytic processes which offer the most sustainability, this two-part book explores recent developments in this field, as well as examining future challenges.Focussing on catalysis through non-endangered metals, chapters are dedicated to the most important sustainable metals in catalysis: titanium, iron and aluminium. Remaining chapters examine several other important metals. Green aspects of the various reactions are also discussed, such as atom economy and use of green solvents and other reaction conditions.Together with Sustainable Catalysis: Without Metals or Other Endangered Elements, these books examine the progress in sustainable catalysis in all areas of chemistry, and are an important reference for researchers working in catalysis and green chemistry.
Sub-Genre: Environmental Science
Series Title: RSC Green Chemistry
Publisher: Royal Society of Chemistry
Street Date: November 16, 2015
Item Number (DPCI): 248-00-1804 | <urn:uuid:17edccd5-b1fa-44fb-8fe9-3f2fe31fa3ab> | 3.03125 | 219 | Product Page | Science & Tech. | 6.720906 | 95,488,785 |
Simon Landhausser - Role of plant species selection in rebuilding of resilient forest ecosystems
Resource extraction results in severe disturbance to landscapes representing a range of boreal forest ecosystems. In Canada, operators are obligated to "revegetate the disturbed land to… self-sustaining, locally common boreal forest … ." An understanding of the natural processes, relationships, and dynamics in these forest ecosystems is key to rebuilding resilient and sustainable boreal forests. In this context resilience can encompass both recovering from the mining disturbance and the capacity to recover from future natural disturbances and stresses. In this presentation I will discuss the aspect of selection and establishment of plant species in restoring diverse and productive forest ecosystems, which therefore possess properties that are likely to confer resilience. Recognizing the role of the species being reintroduced during the recovery of severely disturbed areas is critical in determining the trajectories along which reclaimed forest stands develop. As such, the autecology and life-history traits of these species and their abundance through time and space are critical to assess resistance and resiliency of these future ecosystems. In this presentation I will give examples of some of the roles plants and their traits play in the development of resistance and resiliency in reclaimed novel ecosystems emphasizing linkages among plants and ecosystem processes. | <urn:uuid:0d1f00c7-b0eb-4f51-a754-c971d13330c4> | 2.671875 | 254 | Truncated | Science & Tech. | -0.510502 | 95,488,795 |
Scientists amazed after five migrating cuckoos fitted with GPS trackers meet up in the same spot in Africa
All the birds (not pictured) are now relatively close, with three about as close to each other as they were when they were caught in Norfolk and Suffolk in May and June
Scientists have been left astonished after five cuckoos who headed south from Britain for the winter have congregated in the same little-known part of Africa.
British conservationists decided to track their movements to find out more about the birds' lifestyles following concerns about their dwindling numbers.
After leaving East Anglia in June, the birds - Clement, Kasper, Martin, Chris and Lyster - flew thousands of miles apart as they made their way to warmer climes.
Three of the birds, Chris, Martin and Kasper, flew down through Italy and straight across the Sahara desert.
The other two, Clement and Lyster, went to Spain and down the Atlantic edge of the continent, more than 1,000 miles to the west.
Yet now it's been discovered they are all now relatively close, in the Congo rainforest, despite having travelled around 3,000 miles south.
Incredibly, three are about as close to each other as they were when they were caught in Norfolk and Suffolk in May and June.
Experts said their journey was fraught with danger with crossing the Sahara was one of the major sources of mortality for many migrants.
Chris - named after BBC wildlife presenter Chris Packham - crossed the desert on July 23 and was in Chad negotiating a lava field around the rim of a volcano.
The trackers, fitted by scientists from the British Trust for Ornithology, transmit for 10 hours and then go into 'sleep' mode for 48 hours to allow the solar panel to recharge the battery.
After leaving East Anglia in June, all the birds - Clement, Kasper, Martin, Chris and Lyster - reached Africa but used very different routes
Scientists wanted to use the information about their routes, wintering grounds and habitats to form conservation strategies to save them.
Cuckoo numbers have plummeted by
two-thirds in the last 25 years, leaving as few as 7,000 breeding pairs
migrating here from Africa each spring.
And scientists are struggling to explain a catastrophic decline in the number of birds whose annual visits are part of our folklore.
CUCKOOS: WHERE ARE THEY?
Clement, Martin, Lyster are all wintering on the Téké plateau north of the Congo capital, Brazzaville, a sparsely-inhabited area of grasslands with forests along the rivers
Kasper is at present on the Téké plateau's southern end, about 30 miles north of Brazzaville
Chris is currently farthest to the north-west, just over the border in the Democratic Republic of the Congo.
With no one quite sure what is behind the fall – which is much more pronounced in England than in Scotland – there are very real concerns about the cuckoo’s future.
Possible reasons include a drop in the hairy caterpillars it feasts on while on British soil.
Hewson, research ecologist at the British Trust for Ornithology, said: 'We have gained completely new knowledge which will be invaluable in understanding the migratory cycle and planning ways to help the declining populations of these amazing birds.'
It had been thought that the cuckoo, which famously does not build its own nest, might be a victim of climate change.
feared that birds the cuckoo relies on to rear its young, such as
the dunnock and meadow pipit, were nesting earlier, meaning the cuckoos
weren't making it back from Africa in time to take advantage of their
But research shows this isn't the case.
Deforestation and other forms of habitat destruction in Africa may also be in the frame.
But, as yet, no one is sure just where in Africa the cuckoos go – or how much they move around when they get there.
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A-level Physics/Forces, Fields and Energy
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Forces, Fields and Energy is the main module of the A2 year. You will need to know everything from the previous 3 modules from last year. There is a lot to learn this year, but here is where things start to get really interesting!
- Further dynamics
- Work and energy
- Motion in a circle
- Gravitational fields
- Electric fields
- Electromagnetic induction
- Thermal physics
- The nuclear atom
- Appendix of Formulae
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Hurricanes Katrina and Rita focused the international spotlight on the vulnerability of the U.S. coastline. Fears that a "super-hurricane" could make a direct hit on a major city and cause even more staggering losses of life, land and economy triggered an outpouring of studies directed at every facet of this ferocious weather phenomenon. Now, an LSU professor takes us one step closer to predicting the future by drilling holes into the past.
Kam-biu Liu, George William Barineau III Professor in LSU's Department of Oceanography and Coastal Sciences, is the pioneer of a relatively new field of study called paleotempestology, or the study of prehistoric hurricanes. Liu, a long-time resident of Louisiana, became even more interested in the subject during the aftermath of Hurricane Katrina, when a national debate was sparked concerning hurricane intensity patterns and cycles.
"People were discussing the probability of a Category 5 hurricane making direct impact on New Orleans," said Liu. "That's tricky, because it's never actually happened in history. Even Katrina, though still extremely powerful, was only a Category 3 storm at landfall."
Currently, experts tend to agree that Atlantic hurricane activity fluctuates in cycles of approximately 20-30 years, alternating periods of high activity with periods of relative calm. But records of such events have only been kept for the last 150 years or so. What would happen, Liu wondered, if you looked back thousands of years? Would larger cycles present themselves?
How does a scientist study storms that happened during prehistoric times? "Basically, we worked under the assumption that the storm surge from these catastrophic hurricanes would have the capability to drive sand over beach barriers and into coastal lakes," said Liu. "This is called an overwash event. We believed that pulling sediment cores from coastal lakes and analyzing the sand layers might give us the information we needed." The same methodology can be used to find overwash sand layers in coastal marshes. Using radiocarbon analysis and other dating techniques, Liu and his research team worked to develop a chronology of prehistoric storms in order to analyze any emerging patterns or cycles.
This methodology has proven successful for the group. In an article printed in the March issue of American Scientist, the magazine of Sigma Xi, the Scientific Research Society, Liu states that evidence from the Gulf Coast drill sites shows that hurricanes of catastrophic magnitude directly hit each location only approximately 10 – 12 times in the past 3,800 years. "That means the chances of any particular Gulf location being hit by a Category 4 or Category 5 hurricane in any given year is around 0.3 percent," said Liu.
After spending more that 15 years studying dozens of lakes and marshes along the U.S. Gulf and Atlantic Coasts, Liu and his students are moving on to a more tropical location. Liu was recently awarded more than $690,000 from the Inter-American Institute for Global Change Research, or IAI, for his new project titled "Paleotempestology of the Caribbean Region," which is slated to run for five years. He serves as the principal investigator for this international and multi-disciplinary project, which involves 12 other co-investigators from four different countries, including another contributor from LSU, Nina Lam, a professor in the Department of Environmental Studies.
Institutions participating in the study include:
the Woods Hole Oceanographic Institution,
the University of Tennessee,
the University of Toronto,
the Memorial University of Newfoundland,
the University of Costa Rica,the Instituto Mexicano de Tecnologia del Agua, or IMTA, in Mexico.
Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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Simulations of relativistic runaway breakdown (RRB) are performed as functions of both time and space, resulting in explicit calculations of e-folding lengths (λ) and times (τ). The ratio of λ to τ agrees well with the speed of the avalanche, which ranges from 2.61 × 108 m s-1 to 2.72 × 108 m s-1. Thus, using the speed of light, c, for the ratio of λ to τ can cause a 10% error when estimating λ from τ. A 10% error in λ will cause a factor of three error in the predicted number of runaway electrons for every ten estimated e-foldings. In addition, previous models that predict peak radiated electric fields from RRB have used avalanche speeds of 0.987c and higher. Using a propagation speed of 0.89c causes a dramatic change in the predicted beaming pattern of electromagnetic radiation caused by RRB in these models.
Mendeley saves you time finding and organizing research
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But now comes a surprise. When students went to downtown Seattle to count bird species, within the first 10 to 15 minutes they spotted pigeons, finches, sparrows, crows and an occasional hummingbird.
Their count was 10 to 15 different kinds of birds — not many, but they expected that.
When they went the other way (to the far edge of the metropolitan area near the Cascade Mountains, where there is mostly forest, protected parks, reservoirs, and humans are sparse), in the first 10 to 15 minutes, they found a very different set of birds (woodpeckers, wrens, warblers, chickadees).
In all, 20 different species — more, but not many more than downtown.
Then they went to the in-between zone, the Seattle suburbs, where they expected an in-between count, something like 12 different kinds of birds. But that’s not what happened.
Birds in the suburbs.
“We were astonished,”
Marzluff writes. The suburban count (again in the first 10 minutes) was “30 or more species,” says Marzluff, some from downtown, some from the mountains, but also spectacularly new samples of “violet-green swallows, willow flycatchers, killdeer, orange crowned warblers, American goldfinches, and Bewick’s wrens … [plus a few] white crowned sparrows.”
The suburbs produced, by far, the most biologically diverse collection of birds.
What? This region that’s all sprawl, a hodgepodge of strip malls, yards, highways, parking lots, hedges, fences, is “a mecca for birds”? More than a forest? No way, thought Marzluff. So he counted again. Then again.
And after checking and compiling “more than 100 locations in and around Seattle,” he writes, he and his team discovered “a consistent, but unexpected relationship between the intensity of development and bird diversity.”
To his great surprise, Marzluff concluded that the “greatest diversity was not in the most forested setting. Instead, bird diversity rose quickly from the city center to the suburbs and then dropped again in the extensive forest that eases Seattle into the high Cascades.”
If you plotted it on a graph, bird biodiversity looks like this …
This majestic creature is a Victoria Crowned Pigeon (Goura victoria), a large, bluish-grey bird native to New Guinea. The bird is named in honor of the British monarch Queen Victoria.
The elegant crest of feathers on its head also forms the pigeon’s “crown.”
In addition to its bluish hue, the Victoria Crowned Pigeon has several features that distinguish it from the pigeons that roam around New York City: It has a distinctive, maroon breast, a crest of feathers with white tips, and bright red irises.
The Victoria Crowned Pigeon is the largest of all living pigeons, and can even stand as tall as a turkey. Photo: Wikipedia
Battle of the birds (Graphic: Ryan F. Mandelbaum; Raven: Wikimedia user CanadianWikilover; Crow: Wikimedia user Mdf; Sky: Wikimedia user Mohammed Tawsif Salam, Screenshot via Nintendo, Wikimedia Commons)
Crows and ravens are hard to tell apart, but basically, the common raven is bigger than the American and Northwestern crow.
So you might think that ravens would win in a fight. But that doesn’t seem to be the case.
One thing you might not know about bird nerds is that many of us are citizen scientists, logging all of the birds we see, along with our observations, into an online database called eBird.
It’s a worthwhile endeavour that can lead to new scientific insights about birds.
A pair of scientists analysed 2000 eBird logs and learned about this strange corvid behaviour.
“Both crows and ravens are insanely smart species, but our cities and agricultural areas are hugely dominated by crows, while ravens live in more wild areas,” study author Benjamin Freeman, postdoctoral researcher at the University of British Columbia, told Gizmodo.
“Crows’ social behaviour helps them keep their domination in cities and agricultural areas.”Basically, the raven, being a big cousin of the crow, would probably win in a one-on-one fight, but such events rarely happen in the wild, said Freeman.
Instead, crows band into small groups to chase and attack ravens — 97 per cent of the time, the crows are the aggressors, according to the paper published in The Auk Ornithological Advances.
These attacks occur more frequently during crow’s nesting season or during winter, implying that the crows could be preemptively fending off larger potential predators or fighting for resources like food. | <urn:uuid:a12343ec-7ee1-4350-9eed-f8130143e333> | 2.9375 | 1,049 | Personal Blog | Science & Tech. | 48.645681 | 95,488,863 |
|Debugging with GDB|
A trace state variable is a special type of variable that is
created and managed by target-side code. The syntax is the same as
that for GDB's convenience variables (a string prefixed with “$”),
but they are stored on the target. They must be created explicitly,
tvariable command. They are always 64-bit signed
Trace state variables are remembered by gdb, and downloaded to the target along with tracepoint information when the trace experiment starts. There are no intrinsic limits on the number of trace state variables, beyond memory limitations of the target.
Although trace state variables are managed by the target, you can use
them in print commands and expressions as if they were convenience
variables; gdb will get the current value from the target
while the trace experiment is running. Trace state variables share
the same namespace as other “$” variables, which means that you
cannot have trace state variables with names like
$pc, nor can you have a trace state variable and a convenience
variable with the same name.
tvariablecommand creates a new trace state variable named
$name, and optionally gives it an initial value of expression. The expression is evaluated when this command is entered; the result will be converted to an integer if possible, otherwise gdb will report an error. A subsequent
tvariablecommand specifying the same name does not create a variable, but instead assigns the supplied initial value to the existing variable of that name, overwriting any previous initial value. The default initial value is 0. | <urn:uuid:5b8d8504-788e-4138-9efb-2a25e55d17c6> | 2.828125 | 336 | Documentation | Software Dev. | 31.688984 | 95,488,864 |
“The discovery of the first active vents ever found on an ultraslow-spreading ridge is a significant milestone event,” said Jian Lin, leader of a team of Woods Hole Oceanographic Institution (WHOI) scientists who participated in a Chinese expedition to the remote Southwest Indian Ridge in the Indian Ocean in February and March.
Since deep-sea hydrothermal vents were first discovered 30 years ago in the Pacific Ocean, scientists have studied them all along the Mid-Ocean Ridge, a 40,000-mile-long mountain range that zigzags through the middle of the world’s ocean basins like a giant zipper. The ridge marks the area where the Earth’s giant tectonic plates spreads apart and new ocean crust forms from hot lava rising from deep within Earth’s mantle.
Most studies of the chimney-like vent structures have taken place along ridges in the “fast-spreading” East Pacific Rise (100 to 200 millimeters per year) and the “slow-spreading” Mid-Atlantic Ridge (20 to 40 millimeters per year). Only in recent years have scientists explored “ultraslow-spreading ridges” (less than 20 millimeters per year) in the Arctic and Indian Oceans—remote areas tough to get to, and therefore the least studied.
Scientists initially thought ultraslow-spreading ridges would be too cold to host large hot vents. But in the past decade, some scientists began to hypothesize that the slower a ridge spreads, the fewer vents it would have—but the bigger the vent fields would be.
“This cruise confirmed that hypothesis,” said Lin, a marine geophysicist and U.S. Coordinator of the 20-day expedition aboard the Chinese research vessel Dayang 1. “People have been looking for active hot vents on ultraslow ridges for more than 10 years,” Lin said.
In 2005-06, as part of China’s first around-the-world oceanographic expedition, Lin had sailed as a US chief scientist on Dayang 1 to the Southwest Indian Ridge, where scientists found tantalizing evidence of active hydrothermal venting. They gathered critical data that led them back to the site this year.
During the February-March expedition, the team nailed the discovery with the aid of ABE, WHOI’s Autonomous Benthic Explorer, which has been instrumental in recent years in helping scientists find vents on the bottom of the ocean much quicker than ever before. ABE acts like a robotic deep-sea bloodhound: In a sequence of dives, its sensors “sniff out” clues indicating a plume of fluids emanating from a vent and collect data scientists use to home in on the vent.
ABE also uses sonar to create maps of vent fields and takes photographs about 5 meters above them. ABE snapped 5,000 images of the robust Southwest Indian Ridge vent site, which is among the largest known to date. It is larger than a football field (120 meters by 100 meters).
The discovery was a first for China. “This discovery reflects China’s increasing contribution to ocean science in general, and ridge science in particular,” Lin said.
The China Ocean Mineral Resources R&D Association (COMRA) in Beijing, China, funded the 2005-06 expedition and ABE’s participation in the current one. COMRA, which represents China in the International Seabed Authority, has been exploring the deep sea for mineral resources since the early 1990s.
China is increasing investments in ocean science, Lin said. COMRA’s primary interests lay in the large sulfide deposits created by hydrothermal vents, which are rich in copper, zinc, gold, and other minerals, he said.
“Our Chinese colleagues were the happiest people I’ve ever seen at sea when they brought the first samples aboard,” said Dana Yoerger, scientist in the WHOI Deep Submergence Laboratory and co-designer of ABE, who participated in the expedition. Once ABE pinpointed the site’s exact location, the Chinese team sent down its “TV grab”— a grappling device guided by a television camera—and retrieved a reddish chunk of a vent chimney, Yoerger said.
The researchers outran a tropical cyclone and collected the data they needed in just six days and three ABE dives. “It was the most ruthlessly efficient science we’ve ever done,” said Christopher German, chief scientist of the WHOI-operated National Deep Submergence Facility, who also participated in the expedition. “We had no margin for error.”
The Chinese science party was led by chief scientist Chunhui Tao, a geophysicist at the Second Institute of Oceanography in Hanzhou, China.
“The two international teams worked exceedingly well for this kind of complex operation,” Lin said
Joanne Tromp | EurekAlert!
New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Information Technology
17.07.2018 | Materials Sciences
17.07.2018 | Power and Electrical Engineering | <urn:uuid:f0290850-6451-4b29-ab57-9ea4f4760614> | 3.796875 | 1,666 | Content Listing | Science & Tech. | 44.157697 | 95,488,866 |
Chapter 1 spent quite a bit of time discussing the need for, and introducing, the Entity Framework. As part of that discussion the chapter introduced the EDM (Entity Data Model) and its many benefits to you. As you have learned, the EDM is the bridge between your application and your data and is the component that allows you to work with your data conceptually rather than going directly against your database and trying to figure out the back-end schema.
KeywordsScalar Property Visual Studio Entity Property Empty Model Inheritance Hierarchy
Unable to display preview. Download preview PDF. | <urn:uuid:6d7d2f49-e7d1-4257-a670-1bd6618e750e> | 2.71875 | 120 | Truncated | Software Dev. | 38.875959 | 95,488,892 |
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
Exploring and predicting folding, cutting and punching holes and making spirals.
Each light in this interactivity turns on according to a rule. What happens when you enter different numbers? Can you find the smallest number that lights up all four lights?
There are seven pots of plants in a greenhouse. They have lost their labels. Perhaps you can help re-label them.
The computer has made a rectangle and will tell you the number of spots it uses in total. Can you find out where the rectangle is?
Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?
This interactivity allows you to sort letters of the alphabet into two groups according to different properties.
What is the largest number of circles we can fit into the frame without them overlapping? How do you know? What will happen if you try the other shapes?
These spinners will give you the tens and unit digits of a number. Can you choose sets of numbers to collect so that you spin six numbers belonging to your sets in as few spins as possible?
I am thinking of three sets of numbers less than 101. Can you find all the numbers in each set from these clues?
I am thinking of three sets of numbers less than 101. They are the red set, the green set and the blue set. Can you find all the numbers in the sets from these clues?
Nearly all of us have made table patterns on hundred squares, that is 10 by 10 grids. This problem looks at the patterns on differently sized square grids.
This game challenges you to locate hidden triangles in The White Box by firing rays and observing where the rays exit the Box.
Many natural systems appear to be in equilibrium until suddenly a critical point is reached, setting up a mudslide or an avalanche or an earthquake. In this project, students will use a simple. . . .
What do you think is the same about these two Logic Blocks? What others do you think go with them in the set?
This problem explores the shapes and symmetries in some national flags.
In this investigation we are going to count the number of 1s, 2s, 3s etc in numbers. Can you predict what will happen?
"Tell me the next two numbers in each of these seven minor spells", chanted the Mathemagician, "And the great spell will crumble away!" Can you help Anna and David break the spell?
In this problem, we're going to find sets of letter shapes that go together.
This interactivity allows you to sort logic blocks by dragging their images.
Follow the directions for circling numbers in the matrix. Add all the circled numbers together. Note your answer. Try again with a different starting number. What do you notice?
How does the time of dawn and dusk vary? What about the Moon, how does that change from night to night? Is the Sun always the same? Gather data to help you explore these questions.
A simple visual exploration into halving and doubling.
Can you decode the mysterious markings on this ancient bone tool? | <urn:uuid:0ef260ab-d3a2-49ff-b0bc-dd4f20300aa7> | 3.75 | 690 | Content Listing | Science & Tech. | 73.068532 | 95,488,894 |
What can you say about the values of n that make $7^n + 3^n$ a multiple of 10? Are there other pairs of integers between 1 and 10 which have similar properties?
Discover a handy way to describe reorderings and solve our anagram in the process.
Learn how to use the Shuffles interactivity by running through these tutorial demonstrations.
Balancing interactivity with springs and weights.
On the 3D grid a strange (and deadly) animal is lurking. Using the tracking system can you locate this creature as quickly as possible?
Show how this pentagonal tile can be used to tile the plane and describe the transformations which map this pentagon to its images in the tiling.
The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?
Can you find a way to turn a rectangle into a square?
The diagram shows a 5 by 5 geoboard with 25 pins set out in a square array. Squares are made by stretching rubber bands round specific pins. What is the total number of squares that can be made on a. . . .
If you know the sizes of the angles marked with coloured dots in this diagram which angles can you find by calculation?
We have four rods of equal lengths hinged at their endpoints to form a rhombus ABCD. Keeping AB fixed we allow CD to take all possible positions in the plane. What is the locus (or path) of the point. . . .
Medieval stonemasons used a method to construct octagons using ruler and compasses... Is the octagon regular? Proof please. | <urn:uuid:f2d99558-d3d1-4ded-aa5b-5db840381455> | 2.921875 | 350 | Content Listing | Science & Tech. | 67.398284 | 95,488,911 |
Arms races and cooperation among amoebae in the wild
Microbes are fast becoming the darlings of the social behavior set because their interactions can be understood right down to their genes. They do interesting things, too: Bacteria steal iron from each other, kill each other with toxins that only close relatives can resist, and count each other with quorum sensors.
The social amoeba Dictyostelium discoideum, or Dicty for short, is a powerful social study system because of the hard work of generations of cell and molecular biologists who have figured out many of the mechanisms of its social process. But it takes studies in nature to understand whether Dicty's cooperative behavior benefits relatives, and even whether its social activities occur frequently in nature.
Researchers in the Department of Biology in Arts & Sciences at Washington University in St. Louis are taking a closer look at the wild life of Dicty, using new gene sequencing techniques, as reported in the Proceedings of the National Academy of Sciences.
A social study case in point: Triggered by starvation, tens of thousands of formerly independent Dicty amoebae aggregate into a motile slug that ultimately differentiates into a fruiting body with living spores aloft a stalk made of sterile stalk cells. About 20 percent of cells sacrifice themselves to form the stalk that lifts living spores aloft and helps them disperse. This clear separation into altruists (dead stalk cells) and beneficiaries (living spore cells) is reminiscent of an ant colony where the sterile workers assist their queen in reproducing.
But unlike ants, amoebae sometimes form a social unit made up of unrelated individuals. Taking advantage of the sequenced genome and many known genes of Dicty, David Queller and Joan Strassmann and their team — Suegene Noh, Katie Geist, and Xiangjun Tian — used a clever technique to get around the difficulty of wild studies of Dicty.
First, they created mixtures, or chimeras, of two unrelated Dicty clones and allowed them to starve. They then collected cells at an early stage when the fate of altruists (stalk cell) and beneficiaries (spore cell) was just beginning to be sorted out, and sequenced their RNA to determine what genes were being expressed in this process. For comparison, they also set up a separate control experiment with only a single clone in the mix. Any genes that were more highly expressed differently in the chimera relative to the control are the social genes of interest. To be sure they were not just looking at the artifacts of one pair of clones, they repeated the experiment with four different clone pairs.
"We started with the prediction that social conflict is going to generate rapid evolution, because every time that you evolve a trick against your opponent, that produces a selection pressure on your opponent to evolve against you, and so on," said Queller, the Spencer T. Olin Professor of Biology.
The prediction was upheld. Using 15 genomes of Dicty collected by the authors from soils in Virginia and Texas, they found the 78 genes that were expressed differently in chimera were evolving more rapidly than other genes.
"The presence of genes especially activated in chimera and showing rapid evolution is exciting by itself, but also because it supports the validity of laboratory experiments on social interactions," said Strassmann, the Charles Rebstock Professor of Biology. "The kinds of cheating and competition that we see in the laboratory is thus not an artifact, but something supported by our peek into genes that have evolved over the millennia."
Said lead author Suegene Noh, now assistant professor at Colby College: "It was particularly exciting to see such a clear signal of rapid evolution from these genes because wild individuals can be highly variable even when they are as apparently simple as single-celled amoebae."
The researchers also wanted to explore whether cells become stalk or spore based on kin selection or direct selection. The kin selection explanation predicts that stalk cells are altruists towards spore cells that are their kin, while the direct selection explanation is simply that stalk cells are losers in competition. To test this, the investigators looked at genes expressed in the pre-stalk and pre-spore stages. They found that the kin selection predictions were upheld.
"Together, these two experiments demonstrate that, in nature, stalk cells truly are altruists that give up their lives for relatives," Strassmann said, noting that earlier work had shown that wild fruiting bodies are largely clonal. "But that does not negate the finding that when there are non-relatives in the fruiting body, genes turn on that are under competing selection pressures.
"It's just like 'Alice in Wonderland,' who discovered that she had to run constantly to merely stay in the same place," she said.
This study takes advantage of molecular signatures of evolution in ways that are likely to prove useful in other controversies of microbial social interactions, the authors said.
"All it takes is a question, a target set of genes hypothesized to be under a particular kind of selection, and then a measure of the genetic signature of that selection," Queller said. "For this particular system, it validates the laboratory work that has been going on for decades, an advantage that could also come to other systems." | <urn:uuid:c4b39b3c-225e-4604-897b-0982921cda79> | 3.3125 | 1,093 | News Article | Science & Tech. | 27.014664 | 95,488,912 |
San Antonio, Texas, based Living Slides (www.theliveslide.com) is pleased to announce the launch of an innovative new microscope slide, LiveSlide®, developed in San Antonio and proudly manufactured in…
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Essentially, super-resolution microscopy (SRM)
refers to any optical technique that is used for the purposes of resolving
structures beyond the diffraction-limited resolution of conventional light
The techniques of super-resolution microscopy allows for images to
be viewed under higher resolution for fine mapping of such cellular structures
as neural synapses and Golgi apparatus among others.
Super-resolution can be achieved through a number of methods including:
Although a typical microscope allows for the
visualization of the specimen by magnifying the image, ultimately it fails to
see infinitely small details. This is largely due to the fact that such light
microscopes are heavily limited by the fact that light is a wave that is subject
In a light microscope, the rays of light from
the object converge onto a single point at the image plane during the imaging
process. However, as a result of diffraction, the exact convergence of these
rays is prevented which causes a sharp point on the object to blur in to a
finite-sized spot on the image.
Whereas diffraction limit of resolution may not
affect imaging at the organ or tissue level in light microscopy, it becomes a
problem when zooming in to cells where a large number of the sub-cellular
structures tend to be smaller than the wavelength. Here, it becomes difficult
to use a light microscope to study cell structures in detail.
techniques overcome the challenges of diffraction limit making it possible to
view and study the molecular structure of cells.
is broadly classified into two main categories. These include:
True Super-Resolution Techniques - This
category of super- resolution microscopy captures information within the
Functional Super-Resolution Techniques - This
category of super-resolution microscopy employs experimental techniques for the
reconstruction of the super-resolution image.
True Super-Resolution Techniques
True sub wavelength techniques include the techniques that
Near field scanning optical microscopy (NSOM)
Also referred to as scanning near-field optical
microscopy, this technique uses fiber optic probe to funnel light to the
nanometric dimension. Here, it becomes possible to take fluorescence measurements
with a spatial resolution of tens of nanometers by scanning the probes near the
surface of the sample. This is achieved by focusing the excitation laser
through an aperture with a smaller diameter than the excitation wavelength,
which results in an evanescent field on the other side of the aperture.
this technique, users obtain an order of magnitude improvement far above what
can be achieved using a conventional fluorescent microscope. For instance,
using NSOM, lateral resolution of 20 nm and vertical resolution of between 2
and 5 nm has been attained. Therefore, the technique proves unique and
beneficial in that it helps bridge the gap between spacial resolution between
the optical approaches commonly used and such high resolution techniques as
One of the biggest advantage of ASOM is that it can provide
both optical and spectroscopic data at high spatial resolution in combination
with simultaneous topographic information.
It also has a number of
limitations that include:
zero working distance and
very small field depth
very long scan times for
high resolution images/large specimen areas
very low transmissity of apertures
smaller than the incident light wavelength
4Pi-Microscope is a laser scanning fluorescence
microscope that uses two high resolution objective lenses for illuminating the
sample. Here, the sample is illuminated from both the back and front side.
Using this technique, the problem of blurred images is partially resolved since
both focal light spots are superimposed, which helps remove the blur to a
certain extent. Resolution largely depends on
the effective 4Pi-spot, which is 3 to 5 times sharper than the spot of a
regular confocal microscope. This allows the microscope to be used for studying
various mitochondrial proteins and morphology.
Structured Illumination Microscopy Technologies
This microscopy technique uses a laser-based
wide-field microscopy set-up in which a movable diffraction granting has been
inserted into the excitation beam path. In this set-up, only the Zero order or
first order diffracted laser beams are allowed to pass through the objective.
At the focal plane of the objective, these beams interfere with each other to
create an illumination in stripe. Through superimposition with the sample, the
stripe pattern generates a Moire effect. This technique offers significant
advantages in that it enhances resolution beyond conventional resolution
associated with diffraction, which in turn provides sufficiently high
resolution to get dynamic images of live cells.
Using this technique, users can
capture 85-100 nm distinction, which is very useful in biological sciences.
Some of the benefits of SIM include:
2x increase in spacial
resolution compared to wide-field microscopy
4D imaging at fast frame
Using this technique, there
is no need to employ photoactivable or photoswitchable fluorophores.
While it has a number of advantages, it also has
its limitations which include:
Artifacts may be generated
during image reconstruction.
It is sensitive to
out-of-focus light. This makes it difficult to use with thick/very densely labeled
For most part, true super-resolution techniques
are used in nano-science largely due to the fact that they provide
super-resolution images directly. A good example of this is with NFOM which captures
information contained in the evanescent wave close to the object.
images are obtained as long as the evanescent field around the object is
directly measured. While these techniques have their strengths,
super-resolution technique requires special equipment, which makes the techniques
complex and hard to operate.
Functional Super-Resolution Microscopy
Functional super-resolution techniques include
microscope techniques that use experimental techniques to reconstruct a
This category is further divided into two groups:
Deterministic Super-Resolution - The techniques used here often use fluorophores, which is the
most common emitter in biological microscopy. This shows a non-linear response
to excitation that is used to enhance resolution
Stochastical Super-Resolution - These techniques are
dependent on the chemical complexities of various molecular light sources that
gives them a complex temporal behaviour. This factor makes several close-by
fluorophores emit light at given separate times and become resolvable in time.
Stimulated Emission Depletion Microscopy
Essentially, this technique is used to create
super-resolution images through the selective deactivation of fluorophores and
the minimization of the area of illumination at the focal point to enhance an
achievable resolution for the system.
Stimulated emission depletion microscopy (STED)
microscopy uses two laser beams to illuminate the specimen. Here, an excitation
laser pulse that is generally created by a multiphoton laser is followed
closely by a doughnut-shaped red-shifted pulse (STED beam).
fluorosphores that are exposed to this beam (STED beam) are instantaneously
returned to the ground state by stimulated emission. Here, non-linear depletion
of the fluorescent state by the STED beam is the basis for super-resolution.
Although the two laser pulses may be diffraction-limited, the STED pulse in
this microscope technique is modified in a manner that allows it to feature
zero-intensity point at the center of focus with strong intensity at the
Once the two laser pulses are superimposed, it is only the molecules
that reside at the center of the STED beam that are able to emit fluorescence.
Through this action, the point spread function in effectively narrowed
ultimately increasing resolution beyond the diffraction limit. In order to
generate a complete image, the center zero is raster-scanned across the
specimen in a similar manner to single-photon confocal microscopy.
In STED, the high the intensity of the STED
beam, the more the molecules will emit a stimulated photon (than the
spontaneous photon). STED microscopy offers 20nm of lateral resolution and 40
to 50 nm axial resolution. This makes it particularly useful in structural analysis,
viewing life cells (when combined with other methods such as fluorescence
One of the main problems associated with STED
microscopy is with regards to photo bleaching, which can occur as a result of
excitation in higher excited states of excitation in the triplet state.
For this microscopy technique, fluorescent
markers are typically used depending on given conditions. For instance, the
marker may be freely excited from the ground state and return spontaneously
through emission of the fluorescence photon. On the other hand, if light of
appropriate wavelength is additionally applied, then the dye can be excited to a
long lived state (where fluorescence does not occur).
Being a RESOLFT technique
(REversible Saturable Optical Linear Fluorescence Transitions) ground state
depletion exhibits a time-sequential readout from within the diffraction zone
at given defined coordinates by using reversible saturable/photoswitchable
It also requires lower laser intensities employed in such
techniques as STED given that it employs a metastable triplet state that has a
lifetime range in the milliseconds to microseconds. With GSD microscopy, users
will benefit from an acquisition time of between 2 and 10 minutes with a
maximum resolution of 20 nm.
Saturated Structured Illumination Microscopy
Like SPEM (saturated pattern excitation
microscopy) saturated structured illumination microscopy (SSIM) is a non-linear
method that depletes the fluorophore ground state by saturated excitation
thereby generating a sinusoidal emission pattern to be recorded onto the
area-array CCD detector.
Here, the saturated excitation illumination produces
narrow line-shaped regions on the zero nodes surrounded by high levels of
fluorescence signal and generates a negative imprint of features that are being
Photo-Activated Localization Microscopy
This technique is a form of localization
microscopy that depends on the ability to isolate, detect and image individual
Nanometer scale resolution in this case is achieved by exploiting
properties of photoswitchable fluorophores. Here, exposing the fluorophores to
given wavelength brings about a change in emission spectra. Here,
photoactivable and reversible photoswitchable fluorophores become fluorescent
while the reversible photoswitchable fluorophores change from a fluorescent
state to another.
With this technique, the basic principle is that
low-power activating laser beam stochastically converts fluorophores with only
a few of these being in their active state. The molecules are then imaged using
a high-power illuminating laser beam so as to immediately convert then back to their
This process (activation and inactivation) is repeated over
thousands of frames in order to ensure that all the molecules have been imaged.
With PALM, it is only by exciting the fluorophores stochastically in a
controlled manner that each dot of fluorescence comes from one fluorophore.
With high labeling efficiencies and specimen
with good signal to noise ratio, it is possible to achieve precisions down to
10 nm using this technique.
Fluorescence Photoactivation Localization
Microscopy (FPALM) brings together a number of existing technologies that produce
images based on fluorescence of individual molecules. For this particular
technique, lasers are used for the purpose of exciting dye molecules on the
surface of the sample. Here, the lasers cause portions of the molecules to
fluoresce giving off a light that creates the image to be captured digitally.
Like in PALM, this process is repeated with new sets of molecules being
excited. The resolution of images using this technique has been shown to be
about 20 times better compared to other traditional light microscopes. As such,
the microscope is capable of creating images with a as low as 10 to 20 nm
Functional super-resolution techniques have
become very important in biological imaging. This is largely due to the fact
that they are relatively easy to realize as is the case with SSRM. Although
they present various advantages, there are also a number of challenges with
these techniques given that some techniques like STED may prove complicated
with relatively slow image acquisition.
There are a number of differences between
super-resolution microscopy and electron microscopy. For instance, whereas
super-resolution microscopy is a form of light microscopy (where light has to
be manipulated to overcome the problems of light diffraction) electron
microscopy is different in that it relies on electrons for imaging. On the
other hand, super-resolution can be used to view and study cellular processes
as they happen. This is to say that it can be used for viewing live cells and
thus various cell structures or other molecules.
When it comes to
electron microscopy, the sample is usually placed in a vacuum, which means that
it is difficult to use electron microscopes to view and study live cells.
Electron microscopy has an advantage over super-resolution microscopy, however, in that it is capable of much greater resolution that has allowed for better
study of various molecular structures and protein molecules (EM spatial
resolution approaches molecular and atomic levels).
has been shown to be relatively easy to use as is the case with methods like
structured illumination microscopy (SIM). Here, sample preparation has been
shown to be more similar to such methods as wide field/confocal microscopy.
This is not the case with electron microscopy, which requires more complicated
Applications and Benefits of Super-Resolution Microscopy
With super-resolution microscopy, scientists and
researchers are no longer limited to the type of resolution that only relied on
fixed tissue. Through such techniques as STED, it has now become possible to
view and study live specimens and reorganization of dynamic protein. This is
due to the fact that the technique can penetrate the tissue sample and allow
for fast image acquisition.
While electron microscopy has a lot to offer in medical research and biology, it proves less beneficial when it comes to live specimen visualization in addition to the fact that electron microscopes are very costly with complicated specimen preparation procedures.
Super-resolution microscopy also allows for detailed close-up images of such microbes as malaria parasites and viruses to be viewed and studied. As such, it overcomes the challenges of the typical microscopes making it a valuable tool in clinical research and biology.
Some of the benefits of
super-resolution microscopy include:
It can be used for studying
sub-cellular architecture and dynamics at nano scale. This makes it particularly
beneficial when it comes to studying cell structures.
combines intrinsic optic sectioning with fast data acquisition and dual color
super-resolution to provide quality images in a timely fashion for further
It is capable of capturing
molecules in actions, which can help study and understand their behaviour,
interaction and other characteristics.
It is possible to carry out
live cell imaging and colorization studies using super-resolution microscopy
Details that are smaller
than 50 nm can be quickly resolved.
It can work with standard
It can minimize drift for
accurate localization of molecules when combined with suppressed motion technology.
Microscopy Imaging Techniques
Brightfield Microscopy - the most elementary microscopy technique but important to understand and apply correctly.
Oil Immersion Microscopy - when used properly increases the refractive index of a sample/specimen. With only a few disadvantages, slides prepared with oil immersion techniques work best under higher magnification where oils increase refraction despite short focal lengths.
The Confocal Microscope - check out how image details can be viewed through state of the art technology and lasers are impossible to view using a conventional microscope.
Phase Contrast Microscope - learn about an entire new world that has opened up in the field of microscopy. Once limited to bright field illumination phase contrast observation is now a standard feature on almost all modern microscopes.
Fluorescence Microscope - study the most used microscope in medical/biological fields which uses high powered light waves to provide unique image viewing options.
Dark Field Microscope - learn more about how when the light source is blocked off, light scatters as it hits the specimen and is then able to reveal details otherwise difficult to see.
Polarizing Microscope - discover its use in a wide range of applications in fields such as geology, metallurgy and medicine. Essential in obtaining information about the color intensity, structure and composition of a sample.
Kohler Illumination - broaden your knowledge of this technique which evenly illuminates the viewing field providing a bright specimen image and eliminates glare.
Differential Interference Contrast - a microscopy techique which benefits from differences in the light refraction by various sections of living cells and transparent specimens allowing for better visibility during microscopic imaging.
E. Hesper Regoa, Lin Shaob, John J. Macklinb, Lukman
Winotoc, Göran A. Johanssond, Nicholas Kamps-Hughesd, Michael W. Davidsone, and
Mats G. L. Gustafsson (2011) Nonlinear structured-illumination microscopy with
a photoswitchable protein reveals cellular structures at 50-nm resolution.
Galbraith CG, and Galbraith JA. Super-resolution microscopy
at a glance. J. Cell. Sci. 2011; 124(Pt 10):1607-11.
Wenhui Wang, Junnan Gu, Ting He, Yangbin Shen, Shaobo Xi,
Lei Tian, Feifei Li, Haoyuan Li, Liuming Yan , and Xiaochun Zhou (2015) Optical
super-resolution microscopy and its applications in nano-catalysis.
Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates
The material on this page is not medical advice and is not to be used for diagnosis or treatment. Although care has been taken when preparing this page, its accuracy cannot be guaranteed. Scientific understanding changes over time. | <urn:uuid:c6854c06-ed77-494c-9c5b-252da62948dc> | 3.484375 | 3,921 | Knowledge Article | Science & Tech. | 15.601949 | 95,488,925 |
Most people would never think of London as a forest. Yet there are actually more trees in London than people. And now, new work by researchers at University College London shows that pockets of this urban jungle store as much carbon per hectare as tropical rainforests.
More than half of the world’s population lives in cities, and urban trees are critical to human health and well-being. Trees provide shade, mitigate floods, absorb carbon dioxide (CO₂), filter air pollution and provide habitats for birds, mammals and other plants. The ecosystem services provided by London’s trees – that is, the benefits residents gain from the environment’s natural processes – were recently valued at £130m a year.
This may equate to less than £20 a year per tree, but the real value may be much higher, given how hard it is to quantify the wider benefits of trees and how long they live. The cost of replacing a large, mature tree is many tens of thousands of pounds, and replacing it with one or more small saplings means you won’t see the equivalent net benefit for many decades after.
The trouble with measuring trees
Trees absorb CO₂ during photosynthesis, which is then metabolised and turned into organic matter that makes up nearly half of their overall mass. Urban trees are particularly effective at absorbing CO₂, because they are located so close to sources such as fossil fuel-burning transport and industrial activity.
This carbon storage potential is an extremely important aspect of their value, but is very hard to quantify. A 120-year-old London plane tree can be 30 metres tall and weigh 40 tonnes or more, and some of the carbon in its tissues will have originated from Victorian coal fires.
Measuring the height of a tall tree is difficult, because it’s rarely clear exactly where the topmost point is; estimating its mass is even harder. Typically, tree mass is estimated by comparing the diameter of the trunk or the height of the tree to the mass of similar trees (ideally the same species), which have been cut down and weighed in the past. This process relies on the assumption that trees of a certain species have a clear size-to-mass ratio.
But a fascinating property of trees is how variable they can be, depending on their environment. So inferring the mass of urban trees from their non-urban counterparts introduces large uncertainties.
Lidar over London
The UCL team use a combination of cutting-edge ground-based and airborne laser scanning techniques, to measure the biomass of urban trees much more accurately. Lidar (which stands for light detection and ranging) sends out hundreds of thousands of pulses of laser light every second and measures the time taken for reflected energy to return from objects up to hundreds of metres away.
When mounted on a tripod on a city street, lidar builds up a millimetre accurate 3D picture of everything it “sees”, including trees. The team are using lidar methods, which they pioneered to measure some of the world’s largest trees, and applying them to trees in the university’s local London Borough of Camden.
The UCL team used publicly available airborne lidar data collected by the UK Environment Agency, in conjunction with their ground measurements, to estimate biomass of all the 85,000 trees across Camden. These lidar measurements help to quantify the differences between urban and non-urban trees, allowing scientists to come up with a formula predicting the difference in size-to-mass ratio, and thus measuring the mass of urban trees more accurately.
The findings show that Camden has a median carbon density of around 50 tonnes of carbon per hectare (t/ha), rising to 380 t/ha in spots such as Hampstead Heath and Highgate Cemetery – that’s equivalent to values seen in temperate and tropical rainforests. Camden also has a high carbon density, compared to other cities in Europe and elsewhere. For example, Barcelona and Berlin have mean carbon densities of 7.3 and 11.2 t/ha respectively; major cities in the US have values of 7.7 t/ha and in China the equivalent figure is 21.3 t/ha.
A story to tell
Trees matter, to all of us. Recent protests in Sheffield, Cardiff, London and elsewhere, over policies of tree management and removal show how strongly people feel about the trees in their neighbourhood. Finding ways to value trees more effectively is critical to building more sustainable and liveable cities.
Measuring trees in new ways also helps us to see them from a new perspective. Some of these trees have incredible stories to tell. Just one example is an ash, tucked away in the grounds of St. Pancras Old Church, one of London’s (and indeed Britain’s) oldest Christian churches.
The tree has an extraordinary arrangement of gravestones around its roots, placed there when the railway was built from St Pancras in the mid-19th century. The job of rehousing the headstones was apparently given to a young Thomas Hardy, working as a railway clerk before going on to achieve literary fame. The UCL team’s 3D lidar data are helping monitor the state of this “Hardy Ash” tree in its dotage. This is just one of the ways new science is helping tell the stories of old trees.
Enjoyed this article? Join 40,000+ subscribers to the ZME Science newsletter. Subscribe now! | <urn:uuid:7a76d642-ac17-42f5-a515-360ca6bfaa53> | 3.984375 | 1,131 | Truncated | Science & Tech. | 48.64702 | 95,488,929 |
(Phys.org)—If you thought antifreeze was only something that was necessary to keep your car from freezing up in the winter, think again. Plants and animals living in cold climates have natural antifreeze proteins (AFPs) which prevent ice growth and crystallization of organic fluid matter. Without such antifreeze, living matter would suffer from frost damage and even death.
Production of such antifreeze proteins is one of the major evolutionary routes taken by a variety of organisms, including fish, insects, bacteria, plants and fungi. Understanding how this mechanism works is not only significant in itself, but also has important implications for improving the world's food and medicinal production, believe researchers from Israel, Canada and the US who investigated how the process works.
Working on unraveling the AFP enigma were scientists from the lab of Dr. Ido Braslavsky of the Hebrew University of Jerusalem and from Ohio University in the US, in collaboration with Prof. Peter L. Davies from Queens University (Ontario, Canada) and Prof. Alex Groisman from the University of California (San Diego, CA), with the support of the National Science Foundation, the Israel Science Foundation, the European Research Council, and the Canadian Institutes of Health Research.
Despite half a century of research, the mechanism underlying the activity of the natural antifreeze proteins is still unclear. One of the debates in the academic community regards the chemistry and physics behind the interactions of antifreeze proteins and ice. In particular, there is an ongoing argument over whether the binding of the proteins to ice is reversible and whether continued presence of these proteins in solution is necessary for prevention of ice growth.
The challenge in unraveling these questions stems from a variety of technical problems associated with the growth and tracking of tiny ice crystals in an environment that mimics the surroundings of the antifreeze proteins in nature.
The Hebrew University researchers studied the antifreeze protein of the yellow mealworm. This protein is a hyperactive AFP with a potency to arrest ice growth that is hundreds of times greater than the potency of fish and plant AFPs.
In their study, published in the American journal Proceedings of the National Academy of Sciences, the international team of researchers biochemically created a fluorescent marker version of the AFP that allowed for direct observation under a microscope lens. They injected this protein into custom-designed microfluidic devices with minute diameter channels.
The microfluidic devices were placed in cooling units engineered with a temperature control at the level of a few thousandth of a degree, so that ice crystals of 20 to 50 micrometers could be grown and melted controllably, all under microscopic observation.
Using their specialized system, the researchers were able to show that ice grown and incubated in an antifreeze solution remains coated with protein and therefore protected. They further showed that the AFPs bind ice directly and strongly enough so as to prevent the ice from growth even after there is no longer any further presence of protein in the solution.
The significance of the findings published in this study is not only on the scientific level but also practical. For example, fish AFPs are already used in low-fat ice cream to prevent ice recrystallization, thereby maintaining a soft, creamy texture. These proteins could be used in other frozen foods for maintaining the desired texture without additional fats, say the researchers.
In medicine, AFPs can be used to improve the quality of sperm, ovules and embryos stored in a frozen state, and for cold or cyropreservation of organs (freezing at extremely low temperatures) for transplantation. They can also be used in cryosurgery and in agriculture.
Other studies on AFPs focus on preparation of recombinant plants and fish with improved survival rates under cold and dehydration conditions. Such recombinant crops may improve food dispersion over the world, the researchers believe.
Explore further: Finding may end a 30-year scientific debate | <urn:uuid:02a6b338-b7d9-4280-a421-a754fc2cc5f0> | 3.71875 | 808 | Truncated | Science & Tech. | 25.60906 | 95,488,936 |
Geologist James Kennett and an international team narrow the date of an anomalous cooling event most likely triggered by a cosmic impact
At the end of the Pleistocene period, approximately 12,800 years ago -- give or take a few centuries -- a cosmic impact triggered an abrupt cooling episode that earth scientists refer to as the Younger Dryas.
New research by UC Santa Barbara geologist James Kennett and an international group of investigators has narrowed the date to a 100-year range, sometime between 12,835 and 12,735 years ago. The team's findings appear today in the Proceedings of the National Academy of Sciences.
The researchers used Bayesian statistical analyses of 354 dates taken from 30 sites on more than four continents. By using Bayesian analysis, the researchers were able to calculate more robust age models through multiple, progressive statistical iterations that consider all related age data.
"This range overlaps with that of a platinum peak recorded in the Greenland ice sheet and of the onset of the Younger Dryas climate episode in six independent key records," explained Kennett, professor emeritus in UCSB's Department of Earth Science. "This suggests a causal connection between the impact event and the Younger Dryas cooling."
In a previous paper, Kennett and colleagues conclusively identified a thin layer called the Younger Dryas Boundary (YDB) that contains a rich assemblage of high-temperature spherules, melt-glass and nanodiamonds, the production of which can be explained only by cosmic impact. However, in order for the major impact theory to be possible, the YDB layer would have to be the same age globally, which is what this latest paper reports.
"We tested this to determine if the dates for the layer in all of these sites are in the same window and statistically whether they come from the same event," Kennett said. "Our analysis shows with 95 percent probability that the dates are consistent with a single cosmic impact event."
All together, the locations cover a huge range of distribution, reaching from northern Syria to California and from Venezuela to Canada. Two California sites are on the Channel Islands off Santa Barbara.
However, Kennett and his team didn't rely solely on their own data, which mostly used radiocarbon dating to determine date ranges for each site. They also examined six instances of independently derived age data that used other dating methods, in most cases counting annual layers in ice and lake sediments.
Two core studies taken from the Greenland ice sheet revealed an anomalous platinum layer, a marker for the YDB. A study of tree rings in Germany also showed evidence of the YDB, as did freshwater and marine varves, the annual laminations that occur in bodies of water. Even stalagmites in China displayed signs of abrupt climate change around the time of the Younger Dryas cooling event.
"The important takeaway is that these proxy records suggest a causal connection between the YDB cosmic impact event and the Younger Dryas cooling event," Kennett said. "In other words, the impact event triggered this abrupt cooling.
"The chronology is very important because there's been a long history of trying to figure out what caused this anomalous and enigmatic cooling," he added. "We suggest that this paper goes a long way to answering that question and hope that this study will inspire others to use Bayesian statistical analysis in similar kinds of studies because it's such a powerful tool."
Julie Cohen | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest
Forest floor C02 efflux (Fff) depends on vegetation type, climate, and soil physical properties. We assessed the effects of biological factors on Fff by comparing a maturing pine plantation (PP) and a nearby mature Oak-Hickory-type hardwood forest (HW). Fff was measured continuously with soil chambers connected to an IRGA during 2001-2002. At both sites, Fff depended on soil temperature at 5cm (T5) when soil was moist (soil moisture, 0> 0.20 m3mm-3)a, nd on both T5 and 0 when soil was drier. A model (Fff( T5,0 )) explained 292% of the variation in the daily mean Fff at both sites. Higher radiation reaching the ground during the leafless period, and a thinner litter layer because of faster decomposition, probably caused higher soil temperature at HW compared with PP. The annual Frt was estimated at 1330 and 1464 g Cm
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The tutorial today will discuss about Ms Access Case Statement. Case Statement is used to specify and give commands to some conditions, similar to if-then-else statement. There are two Case Statement: one for compare an expression to a set of simple expressions to determine the result, while the other one is to evaluate a set of Boolean expressions to determine the result.
The Case Statement only can be used in VBA Code. Syntax for Ms Access Case Statement:
Select Case arguments
Argument: the string or numeric value. It is the value that you are comparing to the list of conditions.
Condition: Evaluated in the order listed. Once a condition is found to be true, the Case statement will execute the corresponding code and not evaluate the conditions any further. You can use multiple Case Condition in one code.
Result: Code that is executed once a condition is found to be true. Following the Condition, it can has more than one result in a code.
Else: the other arguments for condition and result that not listed above.
Table Name: Student Grade
Select Case Grade
[GradeName] = “Perfect”
Case 85 to 99
[GradeName] = “Very Good”
Case 65 to 84
[GradeName] = “Good”
Case Is < 65
[GradeName] = “Failed”
[GradeName] = “Disqualified”
The return value will depends on the Grade entry. So the result will be:
For Query and SQL query, use SWITCH function instead of CASE. This is because CASE only supported for VBA and other programming language. You can see the example of SWITCH function here:
The picture above is the database of books. The Region Field will determine the location of the shelves of each book.
[Region] = “A”, “Shelf Number 200”,
[Region]= “B”, “Shelf Number 400”,
[Region] = “C”, “Shelf Number 700”
The result in the query can be seen like this:
Related Access Database
- access case switch
- case condition in ms access
Access Database Tags: #access case statement between #access case statement in where clause #access case statement multiple conditions #access database case statement syntax #access vba case statement between #access vba case statement multiple conditions #case statement in an access query #case statement in ms access database #ms access and case statement #ms access case statement #ms access case statement between #ms access case statement in where clause | <urn:uuid:6ba2a1bd-bdb6-408c-b55e-623de44d1f9b> | 3.890625 | 545 | Documentation | Software Dev. | 34.424556 | 95,488,953 |
Control of subduction rate on Tonga-Kermadec arc magmatism
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Dehydration/melting of oceanic crusts during returning to the mantle in subduction zones are related to origin of arc lavas. The factors that influence arc magmatism include compositions of the subducting slabs, mantle wedge and subduction rates. However, distinguishing these factors remains difficult and highly debated. Subducting rate is related to the total mass of inputs and controls thermal structure, thus plays a crucial role in arc magmatism. Here we explore the relationships between geochemical variations of arc lavas and convergence rates (increasing from 46 mm/a to the south to 83 mm/a to the northward) in the Tonga-Kermadec arc system. Data of geochemistry for lava samples from nine islands of this arc system are collected and compiled to investigate the role of subduction rate in arc magmatism. Lavas from the northern Tonga arc with a faster subduction rate show broadly lower concentrations of TiO 2 and highfield-strength elements (HFSEs, e.g. Nb, Ta, Zr, Hf), and higher Ba/Th, U/Th ratios than the Kermadec Arc to the south. Some of the Kermadec lavas show the highest values of Th/Nb ratio. We suggest that the northern Tonga arc with a higher subduction rate has been influenced by a stronger role of subductionreleased fluid, which results in stronger large-ion-lithophile elements (LILEs) and relatively weaker HFSEs contribution. It is interpreted that faster subduction rate tend to create a cooler subduction zone, leading to stronger dehydration subduction slab contribution with, thus, higher LILE/HFSE ratios of arc lavas. The conclusion contributes to a better understanding of arc magmatism, and ultimately the long-term chemical differentiation of the Earth. More supplementary geochemical data along Tonga-Kermadec arc and tests in other arcs are needed.
Keywordsubduction rate arc magmatism Tonga-Kermadec Arc
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|Paradigms and models|
|Methodologies and frameworks|
|Standards and Bodies of Knowledge|
Computer programming is the process of building and designing an executable computer program for accomplishing a specific computing task. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms in a chosen programming language (commonly referred to as coding). The source code of a program is written in one or more programming languages. The purpose of programming is to find a sequence of instructions that will automate the performance of a task for solving a given problem. The process of programming thus often requires expertise in several different subjects, including knowledge of the application domain, specialized algorithms, and formal logic.
Related tasks include testing, debugging, maintaining a program's source code, implementation of build systems, and management of derived artifacts such as machine code of computer programs. These might be considered part of the programming process, but often the term software development is used for this larger process with the term programming, implementation, or coding reserved for the actual writing of source code. Software engineering combines engineering techniques with software development practices.
Programmable devices have existed at least as far back as 1206 AD, when the automata of Al-Jazari were programmable, via pegs and cams, to play various rhythms and drum patterns; and the 1801 Jacquard loom could produce entirely different weaves by changing the "program" - a series of pasteboard cards with holes punched in them.
However, the first computer program is generally dated to 1843, when mathematician Ada Lovelace published an algorithm to calculate a sequence of Bernoulli numbers, intended to be carried out by Charles Babbage's Analytical Engine.
In the 1880s Herman Hollerith invented the concept of storing data in machine-readable form. Later a control panel (plugboard) added to his 1906 Type I Tabulator allowed it to be programmed for different jobs, and by the late 1940s, unit record equipment such as the IBM 602 and IBM 604, were programmed by control panels in a similar way; as were the first electronic computers. However, with the concept of the stored-program computers introduced in 1949, both programs and data were stored and manipulated in the same way in computer memory.
Machine code was the language of early programs, written in the instruction set of the particular machine, often in binary notation. Assembly languages were soon developed that let the programmer specify instruction in a text format, (e.g., ADD X, TOTAL), with abbreviations for each operation code and meaningful names for specifying addresses. However, because an assembly language is little more than a different notation for a machine language, any two machines with different instruction sets also have different assembly languages.
High-level languages allow the programmer to write programs in terms that are more abstract, and less bound to the underlying hardware. They harness the power of computers to make programming easier by allowing programmers to specify calculations by entering a formula directly (e.g., ). FORTRAN, the first widely used high-level language to have a functional implementation, came out in 1957 and many other languages were soon developed - in particular, COBOL aimed at commercial data processing, and Lisp for computer research.
Programs were mostly still entered using punched cards or paper tape. See computer programming in the punch card era. By the late 1960s, data storage devices and computer terminals became inexpensive enough that programs could be created by typing directly into the computers. Text editors were developed that allowed changes and corrections to be made much more easily than with punched cards.
Whatever the approach to development may be, the final program must satisfy some fundamental properties. The following properties are among the most important:
In computer programming, readability refers to the ease with which a human reader can comprehend the purpose, control flow, and operation of source code. It affects the aspects of quality above, including portability, usability and most importantly maintainability.
Readability is important because programmers spend the majority of their time reading, trying to understand and modifying existing source code, rather than writing new source code. Unreadable code often leads to bugs, inefficiencies, and duplicated code. A study found that a few simple readability transformations made code shorter and drastically reduced the time to understand it.
Following a consistent programming style often helps readability. However, readability is more than just programming style. Many factors, having little or nothing to do with the ability of the computer to efficiently compile and execute the code, contribute to readability. Some of these factors include:
The presentation aspects of this (such as indents, line breaks, color highlighting, and so on) are often handled by the source code editor, but the content aspects reflect the programmer's talent and skills.
Various visual programming languages have also been developed with the intent to resolve readability concerns by adopting non-traditional approaches to code structure and display. Integrated development environments (IDEs) aim to integrate all such help. Techniques like Code refactoring can enhance readability.
The academic field and the engineering practice of computer programming are both largely concerned with discovering and implementing the most efficient algorithms for a given class of problem. For this purpose, algorithms are classified into orders using so-called Big O notation, which expresses resource use, such as execution time or memory consumption, in terms of the size of an input. Expert programmers are familiar with a variety of well-established algorithms and their respective complexities and use this knowledge to choose algorithms that are best suited to the circumstances.
The first step in most formal software development processes is requirements analysis, followed by testing to determine value modeling, implementation, and failure elimination (debugging). There exist a lot of differing approaches for each of those tasks. One approach popular for requirements analysis is Use Case analysis. Many programmers use forms of Agile software development where the various stages of formal software development are more integrated together into short cycles that take a few weeks rather than years. There are many approaches to the Software development process.
A similar technique used for database design is Entity-Relationship Modeling (ER Modeling).
It is very difficult to determine what are the most popular of modern programming languages. Methods of measuring programming language popularity include: counting the number of job advertisements that mention the language, the number of books sold and courses teaching the language (this overestimates the importance of newer languages), and estimates of the number of existing lines of code written in the language (this underestimates the number of users of business languages such as COBOL).
Some languages are very popular for particular kinds of applications, while some languages are regularly used to write many different kinds of applications. For example, COBOL is still strong in corporate data centers often on large mainframe computers, Fortran in engineering applications, scripting languages in Web development, and C in embedded software. Many applications use a mix of several languages in their construction and use. New languages are generally designed around the syntax of a prior language with new functionality added, (for example C++ adds object-orientation to C, and Java adds memory management and bytecode to C++, but as a result, loses efficiency and the ability for low-level manipulation).
Debugging is a very important task in the software development process since having defects in a program can have significant consequences for its users. Some languages are more prone to some kinds of faults because their specification does not require compilers to perform as much checking as other languages. Use of a static code analysis tool can help detect some possible problems. Normally the first step in debugging is to attempt to reproduce the problem. This can be a non-trivial task, for example as with parallel processes or some unusual software bugs. Also, specific user environment and usage history can make it difficult to reproduce the problem.
After the bug is reproduced, the input of the program may need to be simplified to make it easier to debug. For example, a bug in a compiler can make it crash when parsing some large source file. However, after simplification of the test case, only few lines from the original source file can be sufficient to reproduce the same crash. Such simplification can be done manually, using a divide-and-conquer approach. The programmer will try to remove some parts of original test case and check if the problem still exists. When debugging the problem in a GUI, the programmer can try to skip some user interaction from the original problem description and check if remaining actions are sufficient for bugs to appear.
Debugging is often done with IDEs like Eclipse, Visual Studio, Xcode, Kdevelop, NetBeans and Code::Blocks. Standalone debuggers like GDB are also used, and these often provide less of a visual environment, usually using a command line. Some text editors such as Emacs allow GDB to be invoked through them, to provide a visual environment.
Different programming languages support different styles of programming (called programming paradigms). The choice of language used is subject to many considerations, such as company policy, suitability to task, availability of third-party packages, or individual preference. Ideally, the programming language best suited for the task at hand will be selected. Trade-offs from this ideal involve finding enough programmers who know the language to build a team, the availability of compilers for that language, and the efficiency with which programs written in a given language execute. Languages form an approximate spectrum from "low-level" to "high-level"; "low-level" languages are typically more machine-oriented and faster to execute, whereas "high-level" languages are more abstract and easier to use but execute less quickly. It is usually easier to code in "high-level" languages than in "low-level" ones.
Allen Downey, in his book How To Think Like A Computer Scientist, writes:
Many computer languages provide a mechanism to call functions provided by shared libraries. Provided the functions in a library follow the appropriate run-time conventions (e.g., method of passing arguments), then these functions may be written in any other language.
Computer programmers are those who write computer software. Their jobs usually involve:
Manage research, learning and skills at defaultLogic. Create an account using LinkedIn or facebook to manage and organize your Digital Marketing and Technology knowledge. defaultLogic works like a shopping cart for information -- helping you to save, discuss and share.Visit defaultLogic's partner sites below: | <urn:uuid:a11c5b9f-e544-4795-b81a-f293f0c95e38> | 3.734375 | 2,144 | Knowledge Article | Software Dev. | 20.308252 | 95,488,981 |
Ligation of RNA Molecules by the Hairpin Ribozyme
Ribozymes are capable of catalyzing a variety of RNA cleavage, ligation, and splicing reactions. Of these three reaction types, ligation is the least-studied, primarily because of practical difficulties in achieving reasonable reaction efficiencies. Ribozyme-catalyzed ligation reactions are of interest for several reasons. First, ligation is the critical step in a powerful in vitro selection scheme that has been developed in our laboratory (1, 2, 3). Second, understanding the chemistry, thermodynamics, and kinetics of the ligation reaction is important for understanding the reaction in vitro and in the native biological environment of the ribozyme. Third, learning to exploit the ligation reaction will enhance our ability to manipulate RNA molecules in vitro, and may directly contribute to our efforts to develop a technology of engineered ribozymes for targeted RNA cleavage and recombination in vivo.
KeywordsLigation Reaction Bimolecular Reaction Cyclic Phosphate Phosphodiester Linkage Hairpin Ribozyme | <urn:uuid:32767b00-3509-4687-b5ec-f631044bb8b9> | 3.125 | 222 | Academic Writing | Science & Tech. | -3.105965 | 95,488,987 |
Mars Science Laboratory
MSL cruise configuration
|Mission type||Mars rover|
Primary: 669 Martian sols |
Elapsed: 2112 sols
|Manufacturer||JPL, Lockheed Martin|
|Launch mass||3,839 kg (8,463 lb)|
|Start of mission|
|Launch date||November 26, 2011, 15:02:00.211UTC|
|Rocket||Atlas V 541 (AV-028)|
|Launch site||Cape Canaveral SLC-41|
|Contractor||United Launch Alliance|
August 6, 2012, 05:17 UTC SCET |
MSD 49269 05:50:16 AMT
"Bradbury Landing" in Gale Crater |
Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed Curiosity, a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigating Mars' habitability, studying its climate and geology, and collecting data for a manned mission to Mars. The rover carries a variety of scientific instruments designed by an international team.
MSL successfully carried out the most accurate Martian landing of any known spacecraft, hitting a small target landing ellipse of only 7 by 20 km (4.3 by 12.4 mi), in the Aeolis Palus region of Gale Crater. In the event, MSL achieved a landing 2.4 km (1.5 mi) east and 400 m (1,300 ft) north of the center of the target. This location is near the mountain Aeolis Mons (a.k.a. "Mount Sharp"). The rover mission is set to explore for at least 687 Earth days (1 Martian year) over a range of 5 by 20 km (3.1 by 12.4 mi).
The Mars Science Laboratory mission is part of NASA's Mars Exploration Program, a long-term effort for the robotic exploration of Mars that is managed by the Jet Propulsion Laboratory of California Institute of Technology. The total cost of the MSL project is about US$2.5 billion.
Previous successful U.S. Mars rovers include Sojourner from the Mars Pathfinder mission and the Mars Exploration Rovers Spirit and Opportunity. Curiosity is about twice as long and five times as heavy as Spirit and Opportunity, and carries over ten times the mass of scientific instruments.
Goals and objectivesEdit
The MSL mission has four scientific goals: Determine the landing site's habitability including the role of water, the study of the climate and the geology of Mars. It is also useful preparation for a future manned mission to Mars.
To contribute to these goals, MSL has eight main scientific objectives:
- (1) Determine the nature and inventory of organic carbon compounds
- (2) Investigate the chemical building blocks of life (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur)
- (3) Identify features that may represent the effects of biological processes (biosignatures)
- Geological and geochemical
- (4) Investigate the chemical, isotopic, and mineralogical composition of the Martian surface and near-surface geological materials
- (5) Interpret the processes that have formed and modified rocks and soils
- Planetary process
- (6) Assess long-timescale (i.e., 4-billion-year) Martian atmospheric evolution processes
- (7) Determine present state, distribution, and cycling of water and carbon dioxide
- Surface radiation
- (8) Characterize the broad spectrum of surface radiation, including cosmic radiation, solar particle events and secondary neutrons. As part of its exploration, it also measured the radiation exposure in the interior of the spacecraft as it traveled to Mars, and it is continuing radiation measurements as it explores the surface of Mars. This data would be important for a future manned mission.
About one year into the surface mission, and having assessed that ancient Mars could have been hospitable to microbial life, the MSL mission objectives evolved to developing predictive models for the preservation process of organic compounds and biomolecules; a branch of paleontology called taphonomy.
The spacecraft flight system had a mass at launch of 3,893 kg (8,583 lb), consisting of an Earth-Mars fueled cruise stage (539 kg (1,188 lb)), the entry-descent-landing (EDL) system (2,401 kg (5,293 lb) including 390 kg (860 lb) of landing propellant), and a 899 kg (1,982 lb) mobile rover with an integrated instrument package.
The MSL spacecraft includes spaceflight-specific instruments, in addition to utilizing one of the rover instruments — Radiation assessment detector (RAD) — during the spaceflight transit to Mars.
- MSL EDL Instrument (MEDLI): The MEDLI project's main objective is to measure aerothermal environments, sub-surface heat shield material response, vehicle orientation, and atmospheric density. The MEDLI instrumentation suite was installed in the heatshield of the MSL entry vehicle. The acquired data will support future Mars missions by providing measured atmospheric data to validate Mars atmosphere models and clarify the lander design margins on future Mars missions. MEDLI instrumentation consists of three main subsystems: MEDLI Integrated Sensor Plugs (MISP), Mars Entry Atmospheric Data System (MEADS) and the Sensor Support Electronics (SSE).
Curiosity rover has a mass of 899 kg (1,982 lb), can travel up to 90 m (300 ft) per hour on its six-wheeled rocker-bogie system, is powered by a multi-mission radioisotope thermoelectric generator (MMRTG), and communicates in both X band and UHF bands.
- Computers: The two identical on-board rover computers, called "Rover Compute Element" (RCE), contain radiation-hardened memory to tolerate the extreme radiation from space and to safeguard against power-off cycles. Each computer's memory includes 256 KB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory. This compares to 3 MB of EEPROM, 128 MB of DRAM, and 256 MB of flash memory used in the Mars Exploration Rovers.
- The RCE computers use the RAD750 CPU (a successor to the RAD6000 CPU used in the Mars Exploration Rovers) operating at 200 MHz. The RAD750 CPU is capable of up to 400 MIPS, while the RAD6000 CPU is capable of up to 35 MIPS. Of the two on-board computers, one is configured as backup, and will take over in the event of problems with the main computer.
- The rover has an Inertial Measurement Unit (IMU) that provides 3-axis information on its position, which is used in rover navigation. The rover's computers are constantly self-monitoring to keep the rover operational, such as by regulating the rover's temperature. Activities such as taking pictures, driving, and operating the instruments are performed in a command sequence that is sent from the flight team to the rover.
The rover's computers function on VxWorks, a real-time operating system from Wind River Systems. During the trip to Mars, VxWorks ran applications dedicated to the navigation and guidance phase of the mission, and also had a pre-programmed software sequence for handling the complexity of the entry-descent-landing. Once landed, the applications were replaced with software for driving on the surface and performing scientific activities.
- Communications: Curiosity is equipped with several means of communication, for redundancy. An X band Small Deep Space Transponder for communication directly to Earth via the NASA Deep Space Network and a UHF Electra-Lite software-defined radio for communicating with Mars orbiters.:46 The X-band system has one radio, with a 15 W power amplifier, and two antennas: a low-gain omnidirectional antenna that can communicate with Earth at very low data rates (15 bit/s at maximum range), regardless of rover orientation, and a high-gain antenna that can communicate at speeds up to 32 kbit/s, but must be aimed. The UHF system has two radios (approximately 9 W transmit power:81), sharing one omnidirectional antenna. This can communicate with the Mars Reconnaissance Orbiter (MRO) and 2001 Mars Odyssey orbiter (ODY) at speeds up to 2 Mbit/s and 256 kbit/s, respectively, but each orbiter is only able to communicate with Curiosity for about 8 minutes per day. The orbiters have larger antennas and more powerful radios, and can relay data to Earth faster than the rover could do directly. Therefore, most of the data returned by Curiosity (MSL), is via the UHF relay links with MRO and ODY. The data return via the communication infrastructure as implemented at MSL, and observed during the first 10 days was approximately 31 megabytes per day.
- Typically 225 kbit/day of commands are transmitted to the rover directly from Earth, at a data rate of 1–2 kbit/s, during a 15-minute (900 second) transmit window, while the larger volumes of data collected by the rover are returned via satellite relay.:46 The one-way communication delay with Earth varies from 4 to 22 minutes, depending on the planets' relative positions, with 12.5 minutes being the average.
- At landing, telemetry was monitored by the 2001 Mars Odyssey orbiter, Mars Reconnaissance Orbiter and ESA's Mars Express. Odyssey is capable of relaying UHF telemetry back to Earth in real time. The relay time varies with the distance between the two planets and took 13:46 minutes at the time of landing.
- Mobility systems: Curiosity is equipped with six wheels in a rocker-bogie suspension, which also served as landing gear for the vehicle, unlike its smaller predecessors. The wheels are significantly larger (50 centimeters (20 in) diameter) than those used on previous rovers. Each wheel has cleats and is independently actuated and geared, providing for climbing in soft sand and scrambling over rocks. The four corner wheels can be independently steered, allowing the vehicle to turn in place as well as execute arcing turns. Each wheel has a pattern that helps it maintain traction and leaves patterned tracks in the sandy surface of Mars. That pattern is used by on-board cameras to judge the distance traveled. The pattern itself is Morse code for "JPL" (•−−− •−−• •−••). Based on the center of mass, the vehicle can withstand a tilt of at least 50 degrees in any direction without overturning, but automatic sensors will limit the rover from exceeding 30-degree tilts.
|APXS – Alpha Particle X-ray Spectrometer|
|ChemCam – Chemistry and Camera complex|
|CheMin – Chemistry and Mineralogy|
|DAN – Dynamic Albedo of Neutrons|
|Hazcam – Hazard Avoidance Camera|
|MAHLI – Mars Hand Lens Imager|
|MARDI – Mars Descent Imager|
|MastCam – Mast Camera|
|MEDLI – MSL EDL Instrument|
|Navcam – Navigation Camera|
|RAD – Radiation assessment detector|
|REMS – Rover Environmental Monitoring Station|
|SAM – Sample Analysis at Mars|
The general analysis strategy begins with high resolution cameras to look for features of interest. If a particular surface is of interest, Curiosity can vaporize a small portion of it with an infrared laser and examine the resulting spectra signature to query the rock's elemental composition. If that signature intrigues, the rover will use its long arm to swing over a microscope and an X-ray spectrometer to take a closer look. If the specimen warrants further analysis, Curiosity can drill into the boulder and deliver a powdered sample to either the SAM or the CheMin analytical laboratories inside the rover.
- Alpha Particle X-ray Spectrometer (APXS): This device can irradiate samples with alpha particles and map the spectra of X-rays that are re-emitted for determining the elemental composition of samples.
- CheMin: CheMin is short for 'Chemistry and Mineralogy', and it is an X-ray diffraction and X-ray fluorescence analyzer. It will identify and quantify the minerals present in rocks and soil and thereby assess the involvement of water in their formation, deposition, or alteration. In addition, CheMin data will be useful in the search for potential mineral biosignatures, energy sources for life or indicators for past habitable environments.
- Sample Analysis at Mars (SAM): The SAM instrument suite will analyze organics and gases from both atmospheric and solid samples. This include oxygen and carbon isotope ratios in carbon dioxide (CO2) and methane (CH4) in the atmosphere of Mars in order to distinguish between their geochemical or biological origin.
- Radiation Assessment Detector (RAD): This instrument was the first of ten MSL instruments to be turned on. Both en route and on the planet's surface, it will characterize the broad spectrum of radiation encountered in the Martian environment. Turned on after launch, it recorded several radiation spikes caused by the Sun. On May 31, 2013, NASA scientists reported that a possible manned mission to Mars may involve a great radiation risk based on the amount of energetic particle radiation detected by the RAD on the Mars Science Laboratory while traveling from the Earth to Mars in 2011–2012.
- Dynamic Albedo of Neutrons (DAN): A pulsed neutron source and detector for measuring hydrogen or ice and water at or near the Martian surface. On August 18, 2012 (sol 12) the Russian science instrument, DAN, was turned on, marking the success of a Russian-American collaboration on the surface of Mars and the first working Russian science instrument on the Martian surface since Mars 3 stopped transmitting over forty years ago. The instrument is designed to detect subsurface water.
- Rover Environmental Monitoring Station (REMS): Meteorological package and an ultraviolet sensor provided by Spain and Finland. It measures humidity, pressure, temperatures, wind speeds, and ultraviolet radiation.
- Cameras: Curiosity has seventeen cameras overall. 12 engineering cameras (Hazcams and Navcams) and five science cameras. MAHLI, MARDI, and MastCam cameras were developed by Malin Space Science Systems and they all share common design components, such as on-board electronic imaging processing boxes, 1600×1200 CCDs, and a RGB Bayer pattern filter.
- ChemCam: ChemCam is a suite of remote sensing instruments, including the first laser-induced breakdown spectroscopy (LIBS) system to be used for planetary science, and Curiosity's fifth science camera, the remote micro-imager (RMI). The RMI provides black-and-white images at 1024×1024 resolution in a 0.02 radian (1.1-degree) field of view. This is approximately equivalent to a 1500 mm lens on a 35 mm camera.
- Mars Descent Imager (MARDI): During part of the descent to the Martian surface, MARDI acquired 4 color images per second, at 1600×1200 pixels, with a 0.9-millisecond exposure time. Images were taken 4 times per second, starting shortly before heatshield separation at 3.7 km altitude, until a few seconds after touchdown. This provided engineering information about both the motion of the rover during the descent process, and science information about the terrain immediately surrounding the rover. NASA descoped MARDI in 2007, but Malin Space Science Systems contributed it with its own resources. After landing it could take 1.5 mm (0.059 in) per pixel views of the surface, the first of these post-landing photos were taken by August 27, 2012 (sol 20).
- Engineering cameras: There are 12 additional cameras that support mobility:
- Hazard avoidance cameras (Hazcams): The rover has a pair of black and white navigation cameras (Hazcams) located on each of its four corners. These provide closed-up views of potential obstacles about to go under the wheels.
- Navigation cameras (Navcams): The rover uses two pairs of black and white navigation cameras mounted on the mast to support ground navigation. These provide a longer-distance view of the terrain ahead.
NASA called for proposals for the rover's scientific instruments in April 2004, and eight proposals were selected on December 14 of that year. Testing and design of components also began in late 2004, including Aerojet's designing of a monopropellant engine with the ability to throttle from 15–100 percent thrust with a fixed propellant inlet pressure.
By November 2008 most hardware and software development was complete, and testing continued. At this point, cost overruns were approximately $400 million. In the attempts to meet the launch date, several instruments and a cache for samples were removed and other instruments and cameras were simplified to simplify testing and integration of the rover. The next month, NASA delayed the launch to late 2011 because of inadequate testing time. Eventually the costs for developing the rover reached $2.47 billion, that for a rover that initially had been classified as a medium-cost mission with a maximum budget of $650 million, yet NASA still had to ask for an additional $82 million to meet the planned November launch.
Between March 23–29, 2009, the general public ranked nine finalist rover names (Adventure, Amelia, Journey, Perception, Pursuit, Sunrise, Vision, Wonder, and Curiosity) through a public poll on the NASA website. On May 27, 2009, the winning name was announced to be Curiosity. The name had been submitted in an essay contest by Clara Ma, a then sixth-grader from Kansas.
Curiosity is the passion that drives us through our everyday lives. We have become explorers and scientists with our need to ask questions and to wonder.— Clara Ma, NASA/JPL Name the Rover contest
MSL launched on an Atlas V rocket from Cape Canaveral on November 26, 2011. On January 11, 2012, the spacecraft successfully refined its trajectory with a three-hour series of thruster-engine firings, advancing the rover's landing time by about 14 hours. When MSL was launched, the program's director was Doug McCuistion of NASA's Planetary Science Division.
Curiosity successfully landed in the Gale Crater at 05:17:57.3 UTC on August 6, 2012, and transmitted Hazcam images confirming orientation. Due to the Mars-Earth distance at the time of landing and the limited speed of radio signals, the landing was not registered on Earth for another 14 minutes. The Mars Reconnaissance Orbiter sent a photograph of Curiosity descending under its parachute, taken by its HiRISE camera, during the landing procedure.
Six senior members of the Curiosity team presented a news conference a few hours after landing, they were: John Grunsfeld, NASA associate administrator; Charles Elachi, director, JPL; Peter Theisinger, MSL project manager; Richard Cook, MSL deputy project manager; Adam Steltzner, MSL entry, descent and landing (EDL) lead; and John Grotzinger, MSL project scientist.
Landing site selectionEdit
Over 60 landing sites were evaluated, and by July 2011 Gale crater was chosen. A primary goal when selecting the landing site was to identify a particular geologic environment, or set of environments, that would support microbial life. Planners looked for a site that could contribute to a wide variety of possible science objectives. They preferred a landing site with both morphologic and mineralogical evidence for past water. Furthermore, a site with spectra indicating multiple hydrated minerals was preferred; clay minerals and sulfate salts would constitute a rich site. Hematite, other iron oxides, sulfate minerals, silicate minerals, silica, and possibly chloride minerals were suggested as possible substrates for fossil preservation. Indeed, all are known to facilitate the preservation of fossil morphologies and molecules on Earth. Difficult terrain was favored for finding evidence of livable conditions, but the rover must be able to safely reach the site and drive within it.
Engineering constraints called for a landing site less than 45° from the Martian equator, and less than 1 km above the reference datum. At the first MSL Landing Site workshop, 33 potential landing sites were identified. By the end of the second workshop in late 2007, the list was reduced to six; in November 2008, project leaders at a third workshop reduced the list to these four landing sites:
|Eberswalde Crater Delta||−1,450 m (−4,760 ft)||Ancient river delta.|
|Holden Crater Fan||−1,940 m (−6,360 ft)||Dry lake bed.|
|Gale Crater||−4,451 m (−14,603 ft)||Features 5 km (3.1 mi) tall mountain |
of layered material near center. Selected.
|Mawrth Vallis Site 2||−2,246 m (−7,369 ft)||Channel carved by catastrophic floods.|
A fourth landing site workshop was held in late September 2010, and the fifth and final workshop May 16–18, 2011. On July 22, 2011, it was announced that Gale Crater had been selected as the landing site of the Mars Science Laboratory mission.
The Atlas V launch vehicle is capable of launching up to 8,290 kg (18,280 lb) to geostationary transfer orbit. The Atlas V was also used to launch the Mars Reconnaissance Orbiter and the New Horizons probe.
The first and second stages, along with the solid rocket motors, were stacked on October 9, 2011 near the launch pad. The fairing containing MSL was transported to the launch pad on November 3, 2011.
MSL was launched from Cape Canaveral Air Force Station Space Launch Complex 41 on November 26, 2011, at 15:02 UTC via the Atlas V 541 provided by United Launch Alliance. This two stage rocket includes a 3.8 m (12 ft) Common Core Booster (CCB) powered by a single RD-180 engine, four solid rocket boosters (SRB), and one Centaur second stage with a 5 m (16 ft) diameter payload fairing. The NASA Launch Services Program coordinated the launch via the NASA Launch Services (NLS) I Contract.
The cruise stage carried the MSL spacecraft through the void of space and delivered it to Mars. The interplanetary trip covered the distance of 352 million miles in 253 days. The cruise stage has its own miniature propulsion system, consisting of eight thrusters using hydrazine fuel in two titanium tanks. It also has its own electric power system, consisting of a solar array and battery for providing continuous power. Upon reaching Mars, the spacecraft stopped spinning and a cable cutter separated the cruise stage from the aeroshell. Then the cruise stage was diverted into a separate trajectory into the atmosphere. In December 2012, the debris field from the cruise stage was located by the Mars Reconnaissance Orbiter. Since the initial size, velocity, density and impact angle of the hardware are known, it will provide information on impact processes on the Mars surface and atmospheric properties.
Mars transfer orbitEdit
The MSL spacecraft departed Earth orbit and was inserted into a heliocentric Mars transfer orbit on November 26, 2011, shortly after launch, by the Centaur upper stage of the Atlas V launch vehicle. Prior to Centaur separation, the spacecraft was spin-stabilized at 2 rpm for attitude control during the 36,210 km/h (22,500 mph) cruise to Mars.
During cruise, eight thrusters arranged in two clusters were used as actuators to control spin rate and perform axial or lateral trajectory correction maneuvers. By spinning about its central axis, it maintained a stable attitude. Along the way, the cruise stage performed four trajectory correction maneuvers to adjust the spacecraft's path toward its landing site. Information was sent to mission controllers via two X-band antennas. A key task of the cruise stage was to control the temperature of all spacecraft systems and dissipate the heat generated by power sources, such as solar cells and motors, into space. In some systems, insulating blankets kept sensitive science instruments warmer than the near-absolute zero temperature of space. Thermostats monitored temperatures and switched heating and cooling systems on or off as needed.
Entry, descent and landing (EDL)Edit
EDL spacecraft systemEdit
Landing a large mass on Mars is particularly challenging as the atmosphere is too thin for parachutes and aerobraking alone to be effective, while remaining thick enough to create stability and impingement problems when decelerating with retrorockets. Although some previous missions have used airbags to cushion the shock of landing, Curiosity rover is too heavy for this to be an option. Instead, Curiosity was set down on the Martian surface using a new high-accuracy entry, descent, and landing (EDL) system that was part of the MSL spacecraft descent stage. The mass of this EDM system, including parachute, sky crane, fuel and aeroshell, is 2,401 kg (5,293 lb). The novel EDL system placed Curiosity within a 20 by 7 km (12.4 by 4.3 mi) landing ellipse, in contrast to the 150 by 20 km (93 by 12 mi) landing ellipse of the landing systems used by the Mars Exploration Rovers.
The entry-descent-landing (EDL) system differs from those used for other missions in that it does not require an interactive, ground-generated mission plan. During the entire landing phase, the vehicle acts autonomously, based on pre-loaded software and parameters. The EDL system was based on a Viking-derived aeroshell structure and propulsion system for a precision guided entry and soft landing, in contrasts with the airbag landings that were used in the mid-1990s by the Mars Pathfinder and Mars Exploration Rover missions. The spacecraft employed several systems in a precise order, with the entry, descent and landing sequence broken down into four parts—described below as the spaceflight events unfolded on August 6, 2012.
EDL event–August 6, 2012Edit
Despite its late hour, particularly on the east coast of the United States where it was 1:31 a.m., the landing generated significant public interest. 3.2 million watched the landing live with most watching online instead of on television via NASA TV or cable news networks covering the event live. The final landing place for the rover was less than 2.4 km (1.5 mi) from its target after a 563,270,400 km (350,000,000 mi) journey. In addition to streaming and traditional video viewing, JPL made Eyes on the Solar System, a three-dimensional real time simulation of entry, descent and landing based on real data. Curiosity's touchdown time as represented in the software, based on JPL predictions, was less than 1 second different than reality.
The EDL phase of the MSL spaceflight mission to Mars took only seven minutes and unfolded automatically, as programmed by JPL engineers in advance, in a precise order, with the entry, descent and landing sequence occurring in four distinct event phases:
Precision guided entry made use of onboard computing ability to steer itself toward the pre-determined landing site, improving landing accuracy from a range of hundreds of kilometers to 20 kilometers (12 mi). This capability helped remove some of the uncertainties of landing hazards that might be present in larger landing ellipses. Steering was achieved by the combined use of thrusters and ejectable balance masses. The ejectable balance masses shift the capsule center of mass enabling generation of a lift vector during the atmospheric phase. A navigation computer integrated the measurements to estimate the position and attitude of the capsule that generated automated torque commands. This was the first planetary mission to use precision landing techniques.
The rover was folded up within an aeroshell that protected it during the travel through space and during the atmospheric entry at Mars. Ten minutes before atmospheric entry the aeroshell separated from the cruise stage that provided power, communications and propulsion during the long flight to Mars. One minute after separation from the cruise stage thrusters on the aeroshell fired to cancel out the spacecraft's 2-rpm rotation and achieved an orientation with the heat shield facing Mars in preparation for Atmospheric entry. The heat shield is made of phenolic impregnated carbon ablator (PICA). The 4.5 m (15 ft) diameter heat shield, which is the largest heat shield ever flown in space, reduced the velocity of the spacecraft by ablation against the Martian atmosphere, from the atmospheric interface velocity of approximately 5.8 km/s (3.6 mi/s) down to approximately 470 m/s (1,500 ft/s), where parachute deployment was possible about four minutes later. One minute and 15 seconds after entry the heat shield experienced peak temperatures of up to 2,090 °C (3,790 °F) as atmospheric pressure converted kinetic energy into heat. Ten seconds after peak heating, that deceleration peaked out at 15 g.
Much of the reduction of the landing precision error was accomplished by an entry guidance algorithm, derived from the algorithm used for guidance of the Apollo Command Modules returning to Earth in the Apollo program. This guidance uses the lifting force experienced by the aeroshell to "fly out" any detected error in range and thereby arrive at the targeted landing site. In order for the aeroshell to have lift, its center of mass is offset from the axial centerline that results in an off-center trim angle in atmospheric flight. This is accomplished by a series of ejectable ballast masses consisting of two 75 kg (165 lb) tungsten weights that were jettisoned minutes before atmospheric entry. The lift vector was controlled by four sets of two reaction control system (RCS) thrusters that produced approximately 500 N (110 lbf) of thrust per pair. This ability to change the pointing of the direction of lift allowed the spacecraft to react to the ambient environment, and steer toward the landing zone. Prior to parachute deployment the entry vehicle ejected more ballast mass consisting of six 25 kg (55 lb) tungsten weights such that the center of gravity offset was removed.
When the entry phase was complete and the capsule slowed to about 470 m/s (1,500 ft/s) at about 10 km (6.2 mi) altitude, the supersonic parachute deployed, as was done by previous landers such as Viking, Mars Pathfinder and the Mars Exploration Rovers. The parachute has 80 suspension lines, is over 50 m (160 ft) long, and is about 16 m (52 ft) in diameter. Capable of being deployed at Mach 2.2, the parachute can generate up to 289 kN (65,000 lbf) of drag force in the Martian atmosphere. After the parachute was deployed, the heat shield separated and fell away. A camera beneath the rover acquired about 5 frames per second (with resolution of 1600×1200 pixels) below 3.7 km (2.3 mi) during a period of about 2 minutes until the rover sensors confirmed successful landing. The Mars Reconnaissance Orbiter team were able to acquire an image of the MSL descending under the parachute.
Following the parachute braking, at about 1.8 km (1.1 mi) altitude, still travelling at about 100 m/s (220 mph), the rover and descent stage dropped out of the aeroshell. The descent stage is a platform above the rover with eight variable thrust monopropellant hydrazine rocket thrusters on arms extending around this platform to slow the descent. Each rocket thruster, called a Mars Lander Engine (MLE), produces 400 to 3,100 N (90 to 697 lbf) of thrust and were derived from those used on the Viking landers. A radar altimeter measured altitude and velocity, feeding data to the rover's flight computer. Meanwhile, the rover transformed from its stowed flight configuration to a landing configuration while being lowered beneath the descent stage by the "sky crane" system.
For several reasons, a different landing system was chosen for MSL compared to previous Mars landers and rovers. Curiosity was considered too heavy to use the airbag landing system as used on the Mars Pathfinder and Mars Exploration Rovers. A legged lander approach would have caused several design problems. It would have needed to have engines high enough above the ground when landing not to form a dust cloud that could damage the rover's instruments. This would have required long landing legs that would need to have significant width to keep the center of gravity low. A legged lander would have also required ramps so the rover could drive down to the surface, which would have incurred extra risk to the mission on the chance rocks or tilt would prevent Curiosity from being able to drive off the lander successfully. Faced with these challenges, the MSL engineers came up with a novel alternative solution: the sky crane. The sky crane system lowered the rover with a 7.6 m (25 ft) tether to a soft landing—wheels down—on the surface of Mars. This system consists of a bridle lowering the rover on three nylon tethers and an electrical cable carrying information and power between the descent stage and rover. As the support and data cables unreeled, the rover's six motorized wheels snapped into position. At roughly 7.5 m (25 ft) below the descent stage the sky crane system slowed to a halt and the rover touched down. After the rover touched down, it waited two seconds to confirm that it was on solid ground by detecting the weight on the wheels and fired several pyros (small explosive devices) activating cable cutters on the bridle and umbilical cords to free itself from the descent stage. The descent stage then flew away to a crash landing 650 m (2,100 ft) away. The sky crane concept had never been used in missions before.
Gale Crater is the MSL landing site. Within Gale Crater is a mountain, named Aeolis Mons ("Mount Sharp"), of layered rocks, rising about 5.5 km (18,000 ft) above the crater floor, that Curiosity will investigate. The landing site is a smooth region in "Yellowknife" Quad 51 of Aeolis Palus inside the crater in front of the mountain. The target landing site location was an elliptical area 20 by 7 km (12.4 by 4.3 mi). Gale Crater's diameter is 154 km (96 mi).
The landing location for the rover was less than 2.4 km (1.5 mi) from the center of the planned landing ellipse, after a 563,000,000 km (350,000,000 mi) journey. NASA named the rover landing site Bradbury Landing on sol 16, August 22, 2012. According to NASA, an estimated 20,000 to 40,000 heat-resistant bacterial spores were on Curiosity at launch, and as much as 1,000 times that number may not have been counted.
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- MSL Home Page
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- MSL – Entry, Descent & Landing (EDL) – Animated Video (02:00)
- MSL – NASA Updates – *REPLAY* Anytime (NASA-YouTube)
- MSL – "Curiosity Lands" (08/06/2012) – NASA/JPL – Video (03:40)
- Descent video sim&real/narrated, MSL real time/25fps, all/4fp, HiRise
- MSL – Landing ("7 Minutes of Terror")
- MSL – Landing Site – Gale Crater – Animated/Narrated Video (02:37)
- MSL – Mission Summary – Animated/Extended Video (11:20)
- MSL – "Curiosity Launch" (11/26/2011) – NASA/Kennedy – Video (04:00)
- MSL – NASA/JPL Virtual Tour – Rover
- MSL – Entry, Descent & Landing (EDL) – Timeline/ieee
- MSL – Entry, Descent & Landing (EDL) – Description. (PDF)
- MSL – Pre-Launch Preparations at KSC (Hi-Res Images & Spherical Panoramas)
- Mars Science Laboratory on Twitter
- MSL – Raw Images, Listing by JPL (official) | <urn:uuid:3fd7e429-6811-4126-9f9d-8b9ed015728d> | 2.84375 | 13,178 | Knowledge Article | Science & Tech. | 61.636609 | 95,489,004 |
Since Ddk is often deregulated in human cancers, this new understanding of its role in DNA damage control could help shape new cancer therapies. The research was published in the December 24 issue of Molecular Cell.
Accurate DNA replication is essential for maintaining the stability of the genome. When errors occur, replication halts through a quality control process called the S-phase checkpoint. Replication is only restarted after the errors have been repaired. One of several proteins required for DNA replication, Ddk has long been thought to play an important role in the S-phase checkpoint, despite the lack of definitive evidence. In this study, Burnham researchers show that Ddk actively controls S-phase checkpoint signaling and plays a crucial role in triggering the re-initiation of DNA replication once damage has been repaired.
“This protein kinase complex is not only monitoring DNA replication, it’s also monitoring the S-phase checkpoint,” says Wei Jiang, Ph.D., the study’s principal investigator. “If replication is accurate, then Ddk allows DNA synthesis to continue normally. If there is DNA damage, replication is halted at this checkpoint. The most important thing is to stop replication in order to allow for DNA repair and to avoid catastrophe for the cell. Our study demonstrates that Ddk not only activates the initiation of DNA replication, but it also monitors the checkpoint during DNA damage control and eventually overrides the checkpoint to re-initiates DNA replication.”
These findings suggest a highly complex role for Ddk in DNA replication, S-phase checkpoint monitoring and DNA replication re-initiation after repair. The roles of Ddk in controlling the DNA replication machinery for genome stability and fidelity may make it an excellent target for the development of new cancer treatments.
This study, performed by Toshiya Tsuji, Ph.D. and Eric Lau, Ph.D. from the Jiang laboratory in collaboration with Gary Chiang, Ph.D., was funded by a grant from the National Institutes of Health.About Burnham Institute for Medical Research
Josh Baxt | Newswise Science News
Scientists uncover the role of a protein in production & survival of myelin-forming cells
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NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
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Beginning Ruby On Rails
"A beginner's guide to building web applications with Ruby on Rails"--Cover.
Ruby on Rails is the revolutionary online programming tool that makes creating functional e-commerce web sites faster and easier than ever.
Ruby is perhaps best known as the engine powering the hugely popular Ruby on Rails web framework. However, it is an extremely powerful and versatile programming language in its own right. It focuses on simplicity and offers a fully object-oriented environment. Beginning Ruby is a thoroughly contemporary guide for every type of reader wanting to learn Ruby, from novice programmers to web developers to Ruby newcomers.
Beginning Ruby On Rails E-commerce: From Novice To Professional
Beginning Ruby On Rails E-Commerce: From Novice To Professional BY Christian Hellsten., Laine, Jarkko, 9781590597361 | <urn:uuid:4f406e91-dd20-45cf-be25-b23c15baebdf> | 2.875 | 167 | Product Page | Software Dev. | 26.185909 | 95,489,046 |
The Electrolysis Of Copper From Copper Sulphate Solution Essay Sample
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Introduction of TOPIC
The experiment that I have carried out is to find out how different concentrations of copper sulphate affect the electrolysis of copper. To measure the affect that the different copper sulphate solution concentrations have on the electrolysis of copper, I will use current as my unit of measurement to see how the experiment was affected. From the results that I have found, I can use Faraday’s Law and turn the figures into coulombs.
I predict that when the concentration of the copper sulphate solution is increased, then the current will also increase. The reason for this follows a well-known theory, the collision theory. The theory tells us that with more particles involved (in this case the higher concentration containing more particles) the more energy you will have. The reason is simple; more particles mean more collision between them, which therefore produces more energy. This then means that there would probably be a higher current because you have more electrons in a more concentrated solution producing more energy, and so the current is then made higher.
I could carry out the experiment in two ways; the first would be to measure the change of mass of the copper. However, this method is very difficult to carry out, the reason for this is, you need to take into account the original mass of the electrodes, and you need to be very accurate on knowing if ALL of the copper has been taken from the electrodes, the reason being because some of it could still be left behind and may be very hard to pick up and see.
The second and easier way, is to measure the current. To read the current, an ammeter is needed, which clearly shows the current in Amps at the points within a circuit that you need to measure. From the actual readings, I can work out the percentage mass change of the copper. For the simple reason of the second method being much easier, I have chosen to carry out the experiment in that way.
1. D.C. power supply – for providing the power for the experiment.
2. Ammeter – for measuring the amount of current flowing though the circuit.
3. Electrodes [Anode (+) and Cathode (-)].
4. Circuit wire – for connecting up the apparatus to the power supply.
5. Beaker – for holding copper sulphate solution.
6. Copper sulphate solution – for doing the electrolysis experiment.
7. Glass bridge – this is used to rest the electrodes on
8. Crocodile clips – to put on the wires
9. Measuring cylinder – to measure the different concentrations of copper sulphate solution
10. Copper Sulphate solution
The experiment contains an impure copper anode, which contains about two percent copper. The whole point of the experiment is to get the copper pure enough to be used as copper wiring, which has approximately 99.98 percent pure copper, we need to get the impure copper anode to help make the copper wiring which is so much purer than the anode itself. The purification process begins is at the anode. I predict this because I think that this is where the copper will be deposited, the reason being, electrons are flowing from negative to positive. These electrons get rid of the coppers positive charge, leaving pure copper.
The cathode has a thin sheet of pure copper roughly 99 percent pure. When the current is passed through the electrolysis cell, the copper will pass from the anode to the cathode. This means that the cathode sheet of copper becomes more pure, and at this point becomes roughly 99.99 percent pure copper, however, the impurities that move from the anode to the cathode drop off and are left at the bottom of the beaker.
Temperature – temperature may have an affect on the current. The reason is that if the temperature is higher, then the particles will move more quickly thus causing more collisions and producing more energy. On the contrary, less energy is produced.
Concentration – The main point of the experiment is to see how the concentrations affect the current. I will change the concentration after three tries on each one and then move on to the next concentration value. The reason for taking three tries is to make a fair test because this way, there is less chance of making any errors.
1. Firstly I will have to wear safety goggles at all times when in the lab while I myself or anyone around me is conducting the same experiment.
2. I must ensure that I am wearing an apron or lab coat which will shield my clothes from any spills of the copper sulphate solution.
3. Just to be careful, I will mix the copper sulphate solution concentrations and measure them out next to or above a sink. The reason being, that I do not want any of the solution spilling on to the e
lectrical equipment, as this may have serious consequences attached to it.
5. However, if any spills make their way on to my skin then I would be sure to wash it off with water at the nearest tap.
6. I must make sure not to run to get anything or to hurry to wash off any solution, he risks of any more accidents are to great in this situation and therefore I must carefully walk to the nearest tap to wash off the solution.
7. If I spill any solution on someone else then I will be sure to advise them to wash off the spill with water through the same process that I would take.
8. I must remember to wipe off any spill which land on the workplace so that there is no risk of it coming in contact with anyone else.
9. I must make sure that all electrical wiring is organised so that there is not loose wiring which may cause anyone to trip over, so I will have to keep a regular check on the wiring in case it poses a threat to anyone.
Test 1 Current (Amps)
Test 2 Current (Amps)
Test 3 Current (Amps)
Now I will have to work out the average current of each concentration using the simple method of working out the mean between the three tests.
Test 1 Current + Test 2 Current + Test 3 Current = n
n/number of tests = AVERAGE CURRENT FOR THAT CONCENTRATION
Average Current (Amps) (2dp)
Now I need to work out how many moles of electrons there are in coulombs for each concentration.
Time MULTIPLIED BY Current Quantity of Electrons
Quantity of Electricity DIVIDED BY 96000 Moles of electrons
This is how I will work out the Moles of electrons for each concentration.
Quantity of Electricity / C
Moles of Electrons / C
Analysis and Conclusion:
In this experiment I have found that when the concentration of the copper sulphate solution is changed, then the current will be affected and therefore will also change. This means that the Quantity of Electricity and the Moles of Electrons will also differ as an affect of the change of concentration, it can be said that this is a chain reaction. Basically, when the concentration is increased (in Molar) then the current will also increase and vice versa. When the concentration is raised and the current increases with it, then the Quantity of Electricity is also increased and so is the Moles of Electrons, the opposite happens of course when the process is reversed.
In conclusion I can say that the current in the electrolysis cell increases as the concentration increases, this is what I stated in my prediction, I said that the increase would be due to the collision theory. The theory is what my prediction was based on, the reason being, the more particles that you have the more energy that you will have to make the particles move around more. This would mean that the current would increase because the particles are moving around more and producing more energy.
My prediction was correct, and basing it on the collision theory I think that I have done well to understand the electrolysis of copper from copper sulphate solution.
My results are very satisfactory and I am impressed with the results that I have obtained while working in the conditions that I did with the equipment which is not at all comparable with the real thing. We worked with a model version of the real thing, and fortunately it gave me the correct results to work with and understand. The experiment was very hard to conduct and took some time to get to grips with what I had to do to set it up correctly and how to record, understand and in some cases, calculate results with set formulae. I am happy with my results because as the graph will show you, I was able to draw a best fit line very easily. I have taken three sets of results for each concentration value; the reason for this is to reduce the chances of any anomalies or errors in my results, I have taken the three so that I can make an AVERAGE out of them and then use the average as my result to make the experiment fairer. After finishing my experiment I have a lot of confident in my results as I can easily draw the best fit line on the graph and they look logical.
However, I am not saying that my experiment was completely flawless, as I say; this experiment was just to get the outline of what electrolysis in this case is about and its affects and points etc.
I could have improved my experiment if I had done the following:
1. Firstly, the time that I had to do the WHOLE experiment was just sufficient to get results that were valid, however, if I had a longer time to conduct the whole experiment, then I would obviously chose a longer period of time than two minutes which is what I worked within for each test. The reason for having a longer time scale would be so that the electrodes would stay within the solution for a longer time increasing the affects of electrolysis and hopefully even enough to completely finish the electrolysing. I had chosen two minutes because of the time restriction and of course because I had to do THREE tests for each concentration of the copper sulphate solution.
2. The way in which I obtained my different concentrations of copper sulphate solution was through mixing the two together to make the mixture. The solution was made by measuring with the naked eye and manual hand, and pouring in the right amount of each element to balance the solution and get to the right concentration. If the concentrations of the solutions were already made for my use with expert accuracy or if I had top scientific equipment to measure out the solution myself, then obviously the results would be more accurate and the concentrations would be fair for the current change etc.
3. If I had extra time then I would certainly take more repeats, this would reduce the risk of any errors or anomalies and so therefore the experiment as a whole would be more trustworthy and accurate (fair).
4. If only the temperature could be controlled I would be able to have much fairer results, because the temperature can affect the rate at which the electrolysis takes place.
This is basically what I would do if I could to make the experiment as a whole much fairer. However, I do think that the experiment was a success and the right results were obtained. | <urn:uuid:c73ca439-aa75-49bd-bd89-9a812d6b2637> | 3.09375 | 2,364 | Academic Writing | Science & Tech. | 49.354739 | 95,489,081 |
Discussion in 'Ham Radio Discussions' started by KL7AJ, Jul 9, 2018 at 10:40 PM.
I'm patiently waiting for a day when c is changed from a constant to a function.
Here is the problem with the so-called "constant" c. If you go back and look at old physics reference books and college textbooks before c was pegged it was found that c did change by a few percentage points every time it was measured. Not huge changes, but more than could be accounted for by experimental error. The biochemist Rupert Sheldrake points this out in several of his lectures, and others have as well...
"On October 20, 1983 the meter was redefined again. The definition states that the meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second. The speed of light is
c = 299,792,458 m/s
The second is determined to an uncertainty, U = 1 part in 1014 by the Cesium clock. The General Conference made the iodine stabilized Helium-Neon laser a recommended radiation for realizing the meter at this time. The wavelength of this laser is
λHeNe = 632.99139822 nm
with an estimated relative standard uncertainty (U) of ± 2.5 x 10−11."
That's great... define C based on the Cesium clock's "seconds", then define the length of a meter in terms of the Cesium atom, and Viola! The speed of light stops changing because now you have a circularly defined constant.
The fact is, we really don't know, and modern science does not seem interested in checking if these constants do change... I suspect that they do, but very very slowly.
To have been "declined, " does that mean you were once "clined?"
Yes, charts and maps DO need to be updated periodically. I doubt my TOPO maps bought 20-30 years ago are anywhere near accurate in regards to current magnetic headings. (But that can be fixed easily; the maps are still accurate and serviceable.)
Or, is "C" a variable constant?
We may have to redefine "vacuum."
I thought that Maxwell was too busy playing with silver hammers to worry about equations...
Speaking of which, Why does I always equal a minus one in "Higher Math"?
Just alter the declination value on the compass and you're good to go. Right?
Sometimes it means "Hell No"
Just ask Paul Thorn.
And it will not be an over-night event either.
I couldn't find any so I tried my hand at a few:
Q: What type cruise ships do flat earther women take their rich husbands on? A: Flatliners
Q: What is the mating call of flat earthers? A: Dueling Banjos.
Q: How fast are you going when you past the end of the flat earth? A: Flat out.
Q: How many fake news journalists does it take for full coverage of the flat earth? A: 100 if you slice them thin enough.
Q: Why do flat earthers wear Depends? A: So they don't crap their pants when they get near the edge.
Q: What did the husband bring home from shopping for his flat earth wife? A: A lift bra.
Q: What do you get when you cross a flat earther with a jouster? A: Flatulance
Q: Why did the chicken cross the flat earth? A: To fall off the other side
Q: If we all live on the top side of the flat earth, who lives on the other side? A: Bats and Count Dracula
Q: Who was the first flat earth man in space? A: A lying husband who just kept digging his hole deeper and deeper.
Q: How did the flat earth husband die? His fat wife fell flat on his face.
Q: Why are there no gay zombies on the flat earth? They all try to dig out by going down.
Q: What kind of cats make the best flat earth pets? A: Road kill cats.
Q: How do men score by explaining the flat earth to women? A: Flattery will get you everywhere.
Q: Why do flat earth referees never flip a coin? You can't flip a coin with heads on one side and nothing on the other.
Q: What is the flat earther's favorite breakfast? A fried egg, a pancake, flat steak, and an onion ring.
Q: How did the flat earther get lost? He went into a round about and couldn't think his way out. | <urn:uuid:7982024e-cbd7-486e-bb3e-d526fe1e0e23> | 2.828125 | 992 | Comment Section | Science & Tech. | 82.907718 | 95,489,083 |
A University of Illinois researcher along with his colleagues at Iowa State and Oklahoma State Universities enlisted private landowners in a grassroots community-building effort to establish a more diverse landscape for native wildlife.
Prescribed fire is applied on reserves, but grazing is typically excluded and herbaceous vegetation is often dominated by grasses. Credit: Ryan Harr. © Ecological Society of America
The Grand River Grasslands has three main problems that pose challenges to conservation efforts: invasive juniper trees, tall fescue, and heavy grazing of cattle. U of I ecologist Jim Miller and his team developed a new model for conservation that begins by raising landowners' awareness of these problems and providing strategies, such as moderate livestock grazing and regularly scheduled controlled burns. Miller and his team identified landowners who are interested in trying something different -- who will, in turn, transfer their newfound knowledge and understanding to larger groups of people in the region.
"We conducted a survey and learned that people recognize burning as a legitimate management tool but don't have experience with it," Miller said. "Most of the landowners have never participated in a controlled burn, so we've essentially lost a fire culture in much of that part of the country."
Miller's team invited landowners to hands-on educational field days at nearby nature reserves to show them how grazing and burning techniques work. They got experience with drip torches and learned how to work with the wind and moisture levels.
"We followed that up with a burn at one of the landowner's savannahs that he was trying to restore," Miller said. "It went really well and was a key step for us in our process because now we're getting landowners to try these new strategies on their own properties."
Miller said the next step in the model is to encourage the landowners to champion these new practices to the larger community. "They go down to the coffee shop and meet their neighbors and friends and tell them about the success they're having with the new practices to control the juniper trees and tall fescue and how well their cattle are doing on these pastures. The neighbors start to pick up on this, and then we have the whole process repeat itself with a larger group of landowners.
"If we're successful with this, we'll start to see changes, not just on individual properties here and there for key landowners but over the whole landscape or the whole region," he said.
According to Miller, the fastest-growing group of landowners in the area is non-traditional. They don't live in the region or come from a farming background, but they instead buy land to hunt deer, turkey, quail, or maybe just to birdwatch. He said that on land with intensive cattle grazing, the cedars can be kept at bay.
"Without burning or grazing, the cedars will take over," Miller said. "Trees seem like a good thing to wildlife enthusiasts, but they don't see that their land will go from being an open grassland to a closed-canopy cedar stand in 20 to 25 years. Under those conditions, there are no deer, no turkey, no quail – it's a biological desert, and it's too late to do much with it. We think we can make the most inroads with the non-traditional owners."
Juniper trees are invasive, largely due to fire suppression. Junipers are a fire-intolerant, woody plant. This particular species of juniper is also called eastern redcedar.
Although that may sound appealing for patio furniture or decking or biofuels, it's not. Miller said there's no market for this type of tree. The trees produce a prodigious seed rain that facilitates rapid colonization of an area when left unchecked. With a survey from aerial photography dating back to 1983, Miller estimated a 3 percent increase in cedar coverage per year.
Tall fescue, an exotic invasive plant that forms a monoculture, greens up early in the spring making it difficult to burn.
"Heavy stocking of cattle is an issue," Miller said. "Cattle quickly reduce available forage to the point that some ranchers feed hay by July and August. That's not quality habitat for grassland birds, which have seen the steepest declines in North America since we've been monitoring bird populations." He said.
"There are at least two things necessary for this model to work: ecological potential in the landscape and some level of social readiness," Miller said. "In the Grand River Grasslands, there is ecological potential, but landowners don't all recognize that eastern redcedar trees are invasive. We're working on that."
Miller says that with conservation, you need a plurality, a variety of approaches, because one size doesn't fit all.
"We're providing a model or a road map for a different way of doing things in conversation," Miller said. "We need to go beyond the traditional jewels-in-the-crown or fortress conservation models, characterized by national parks and other set-asides. Paying people to take their land out of production and creating state and national parks or reserves just aren't enough. This model may not work everywhere, but in some landscapes we think this can work, and we're trying to provide an initial example to demonstrate how it could work.
"It's meant to be a dialogue between, our team, landowners, and other resource management professionals, such as biologists who work for the Department of Natural Resources -- not us telling them what they need to do," he said.
Frontiers in ecology and the environment: Nature reserves as catalysts for landscape change was published in The Ecological Society of America. Lois Wright Morton, David Engle, Diane Debinski, and Ryan Harr contributed. Photos were provided by Ryan Hart, Devin McGranahan, and Dave Engle.
The research was supported by funding from the Iowa State Wildlife Grants Program in cooperation with the U.S. Fish and Wildlife Service and its Grant Competitive Program, the U.S. Department of Agriculture National Research Initiative, the Joint Fire Sciences Program, and the Leopold Center for Sustainable Agriculture.
Debra Levey Larson | EurekAlert!
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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A landmark new study has found that 90 percent of all animals of Earth appeared at the exact same time, debunking everything we know about evolution.
The genetic study, headed by senior research associate at the Program for the Human Environment at Rockefeller University Mark Stoeckle and University of Basel geneticist David Thaler, analyzed millions of DNA barcodes.
Techtimes.com reports: They found out that 9 out of 10 animal species on the planet came to being at the same time as humans did some 100,000 to 200,000 years ago.
“This conclusion is very surprising,” says Thaler, “and I fought against it as hard as I could.”
What Is DNA Barcoding?
Over the last decade, hundreds of scientists collected around 5 million DNA barcodes from 100,000 animal species in different parts of the globe. Stoeckle and Thaler looked through these 5 million genetic imprints to find one of the most surprising discoveries about evolution to date.
There are two types of DNA. Most people know nuclear DNA. This is the DNA containing the genetic blueprint for each single individual. It is passed down from the parents to the offspring. The genome is made from kinds types of molecules arranged in pairs. There are 3 billion of these pairs, which are then used to form thousands of genes.
The other, less familiar type of DNA is one found in the mitochondria of cells. The mitochondria generate energy for the cell and contains 37 genes. One of these is the COI gene, which is used to create DNA barcodes. All species have a very similar mitochondrial DNA, but their DNA is also different enough so we can distinguish between species.
Paul Hebert, biologist and director of the Biodiversity Institute of Ontario, developed a new way to identify species by studying the COI gene.
Born Around The Same Time
In analyzing the COI of 100,000 species, Stoeckle and Thaler arrived at the conclusion that most animals appeared simultaneously. They found that the neutral mutation across species were not as varied as expected. Neutral mutation refers to the slight DNA changes that occur across generations. They can be compared to tree rings because they can tell how old a certain specie or individual is.
As to how that could have happened, it’s unclear. A likely possibility is the occurrence of a sudden event that caused large-scale environmental trauma and wiped out majority of the Earth’s species.
“Viruses, ice ages, successful new competitors, loss of prey — all these may cause periods when the population of an animal drops sharply,” explains Jesse Ausubel, director of the Program for the Human Environment.
Such times give rise to sweeping genetic changes across the planet, causing new species to appear. However, the last time such an occurrence took place was 65 million years ago, when an asteroid hit the Earth and killed off the dinosaurs and half of all other species on the planet.
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Electricity, Magnetism, Fields, and Waves
Most electrical phenomena arise from the motion of the atomic electrons. Bulk matter is composed of two kinds of electrical matter, negatively charged and positively charged. The charge of the electron is negative. The nucleus of an atom contains an equal amount of positively charged protons. Actually, which one we call negative and which one positive is arbitrary, entirely a matter of convention.
KeywordsMagnetic Field Field Line Light Wave Electrical Force Lightning Discharge
Unable to display preview. Download preview PDF. | <urn:uuid:de0e1a9a-b809-4ae2-a574-9712250a95da> | 3.453125 | 109 | Truncated | Science & Tech. | 19.338235 | 95,489,155 |
Geoscience researchers at the University of Massachusetts Amherst, Smith College and the Japanese Agency for Marine-Earth Science and Technology this week unveiled new, GPS-based methods for modeling earthquake-induced tsunamis for southeast Japan along the Nankai Trough. A Nankai-induced tsunami is likely to hit there in the next few decades, says lead author Hannah Baranes at UMass Amherst, and has the potential to displace four times the number of people affected by the massive Tohoku tsunami of 2011.
She and her doctoral advisor Jonathan Woodruff, with Smith College professor Jack Loveless and Mamoru Hyodo at the Japanese agency report details in the current Geophysical Research Letters. Baranes says, "We hope our work will open the door for applying similar techniques elsewhere in the world."
As she explains, after the unexpectedly devastating 2011 quake and tsunami, Japan's government called for hazard-assessment research to define the nation's worst-case scenarios for earthquakes and tsunamis. Baranes notes, "The government guideline has focused attention on the Nankai Trough. It's a fault offshore of southern Japan that is predicted to generate a magnitude 8 to 9 earthquake within the next few decades."
The team's research, supported by the National Science Foundation and a NASA graduate fellowship, began with a study of coastal lake sediments in Japan to establish long-term records of tsunami flooding. Between 2012 and 2014, Baranes and Woodruff collected sediment cores from lakes, looking for marine sand layers washed onshore by past extreme coastal floods. "These sand deposits get trapped and preserved at the bottoms of coastal lakes," she says. "We can visit these sites hundreds or even thousands of years later and find geologic evidence for past major flood events."
A recent study led by UMass Amherst looked at risk in southwestern Japan after the devastating 2011 quake and tsunami. The Japanese government called for hazard-assessment research to define the nation's worst-case scenarios. Study centered on the Nankai Trough, a fault predicted to generate a magnitude 8 to 9 earthquake in coming decades. Credit: UMass Amherst
Results from Lake Ryuuoo, a small lake on an island in the Bungo Channel, show a surprising sand layer washed into Lake Ryuuoo by seawater rushing over a 13-foot-high barrier beach. "We were able to date the layer to the early 1700s, which is consistent with the known Nankai Trough tsunami event of record from 1707," Baranes says.
She adds, "We were a bit puzzled. The Bungo Channel is tucked between two of Japan's main islands and is relatively sheltered from Nankai Trough-generated tsunamis. Given recent tsunamis in the region, a minimum 13-foot tsunami in the channel seemed very unlikely." Further, she points out, the Bungo Channel area today has much sensitive and critical infrastructure, including the only nuclear power plant on the island of Shikoku. This gave the researchers "particular concern" for tsunami hazard there, so they decided to investigate their original finding further using numerical modeling techniques.
As Baranes explains, an earthquake is caused by plates slipping past each other along faults in the earth's crust. That slip causes the earth's surface to deform, to uplift in some places and sink, or subside, in others. "When earthquake-induced uplift occurs on the sea floor, it displaces the entire column of water above it and generates the wave that we call a tsunami," she adds. "We can simulate that process with numerical models."
She and Woodruff tried using one of the most widely-cited models for the 1707 Nankai Trough earthquake to flood Lake Ryuuoo, but this only generated a six-foot tsunami that came nowhere near overtopping the 13-foot barrier beach.
Hannah Baranes. Credit: UMass Amherst
"At that point, we were still stumped," says Baranes. "But it wasn't long before we had a stroke of good luck in learning that a leading expert on tectonic modeling in Japan, Jack Loveless, is a professor just down the road at Smith College." Loveless uses very precise GPS measurements of earth surface motion to model the extent and spatial distribution of frictional locking that causes fault stress to build up between earthquakes.
With Loveless, the team created earthquake scenarios based on GPS estimates of present-day frictional locking along the Nankai Trough and for the first time rigorously tested methods for creating potential future earthquake scenarios from the GPS measurements. They tested various methods for creating a suite of GPS-based earthquake scenarios and simulated the resulting ground surface displacement and tsunami inundation.
Baranes reports that they found GPS measurements of present-day earth surface motion around the Nankai Trough yield an earthquake of a similar magnitude and extent as the 1707 event, and their simulated tsunami heights are consistent with historical accounts of the 1707 event. As for matching the Lake Ryuuoo geologic record, she adds, "Our model earthquake scenarios showed the Bungo Channel region subsiding seven feet and lowering Lake Ryuuoo's barrier beach from 13 to six feet, such that a tsunami with a feasible height for an inland region easily flooded the lake."
Woodruff, who conducted the study as part of a Fulbright fellowship, says, "Although our methodology was well received, our result for the Bungo Channel was met with a lot of skepticism. We needed to find an independent method for validating it." They enlisted Hyodo, who had previously published earthquake scenarios based on models of the Nankai Trough's physical characteristics. His physical model yielded the same focused subsidence in the Bungo Channel, Woodruff reports.
Baranes adds, "His model was also consistent with our GPS-based model in terms of earthquake magnitude, ground surface displacement and tsunami inundation. This was a really neat result because in addition to providing an independent line of evidence for significant tsunami hazard in the Bungo Channel, we demonstrated a connection between the Nankai Trough's physical characteristics and GPS measurements of surface motion." | <urn:uuid:f2b09c7d-89fb-47e9-86de-395c410d4bce> | 3.546875 | 1,270 | News Article | Science & Tech. | 33.411117 | 95,489,174 |
Calculating the stresses in solid rock from measurements of roof movement in a coal seam
Rock Mechanics and Rock Pressure
KeywordsCoal Seam Tangential Stress Normal Displacement Stress Pattern Solid Rock
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Unable to display preview. Download preview PDF.
- 1.T. F. Gorbachev, G. I. Gritsko, and B. V. Vlasenko, On the manifestation of the rheological properties of the solid rock during advance of a working face in a steeply-dipping seam, Fiziko-Tekhn. Probl. Razrab. Polezn. Iskopaemykh, No. 1 (1965).Google Scholar
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- 4.B. V. Vlasenko and G. I. Gritsko, Determination of the stresses in rocks from their known displacements above a seam and in the waste area, Fiziko-Tekhn. Probl. Razrab. Polezn. Iskopaemykh, No. 6 (1965).Google Scholar
- 5.G. I. Gritsko and B. V. Vlasenko, Changes in the stresses in the solid rock when a coal seam is being worked, Fiziko-Tekhn, Probl. Razrab. Polezn. Iskopaemykh, No. 6 (1966).Google Scholar
- 6.L. A. Galin, Contact Problems in the Theory of Elasticity [in Russian], Moscow, GITTL (1953).Google Scholar
© Consultants Bureau 1967 | <urn:uuid:b4dc6e9e-58ae-4d62-ba26-d476e4a3d1f0> | 2.703125 | 426 | Academic Writing | Science & Tech. | 67.398662 | 95,489,191 |
The Moon is tidally locked to the Earth. That is, as the moon orbits the Earth, only one side of it faces us. The dark side of the Moon refers to the side that is always facing away from us. Although we cannot see this side from Earth, the sun does shine on it.
The speed of light is approximately 300,000 kilometres per second. That is, light can travel around the world 7 and a half times in one second! | <urn:uuid:bdb6a10c-f436-42f8-b660-6e60c4e6fdb5> | 3.28125 | 94 | Knowledge Article | Science & Tech. | 78.243611 | 95,489,207 |
Climate. Climate is the average weather (patterns established over decades) of a location Climate refers to Temperatures throughout the year Precipitation throughout the year Susceptibility to particular weather events such as: Monsoons Tornadoes Hurricanes/typhoons Drought.
Tropics, polar circles
" Fundamentals of Mapping ." Intergovernmental Committee on Survey and Mapping. The Intergovernmental Committee on Surveying and Mapping , n.d. Web. 21 July 2010. <http://www.icsm.gov.au/mapping/coordinates.html>.
Walter, Thomas B.. "ocean.currents." DoG, HC - CUNY. N.p., n.d. Web. 21 July 2010. <http://www.geography.hunter.cuny.edu/~tbw/wc.notes/7.circ.atm/ocean_currents.htm>.
Water changes temperature MUCH more slowly than land, so living close to a huge body of water will “moderate” temperatures (warmer in winter and cooler in summer)
Inland (continental) areas face more extreme summers and winters (marine climate and continental climate)
Based on the 5 factors, guesstimate the climate of the city you are assigned:
Toronto, Halifax, Prince Rupert and Winnipeg.
Compare answers with the class.
"Annual Climatology:." Welcome to the National Drought Mitigation Center website!. National Drough Mitigation Center, n.d. Web. 12 Aug. 2010. <http://www.drought.unl.edu/whatis/iclimographs/VancouverMTMP.htm>.
Casey, Joe. "Kelowna A., BC, Canada: Climate, Global Warming, and Daylight Charts and Data." World Climate. N.p., n.d. Web. 25 Aug. 2010. <http://www.climate-charts.com/Locations/c/CN71203011239700.php>.
Pidwirny, Michael. "7(r) Air Masses and Frontal Transitional Zones." Geography : Physical Geography. N.p., n.d. Web. 25 Aug. 2010. <http://www.physicalgeography.net/fundamentals/7r.html>.
Rogers, J. David. "SAY, WHAT IS A 100-YEAR FLOOD." Missouri University of Science and Technology. N.p., n.d. Web. 25 Aug. 2010. <http://web.mst.edu/~rogersda/umrcourses/ge301/what%20is%20a%20100%20year%20flood.htm>. | <urn:uuid:6fe4ab81-71e1-4b23-8bbe-223205fb64b6> | 3.1875 | 583 | Content Listing | Science & Tech. | 67.607224 | 95,489,209 |
The Sun is becoming an increasingly important source of clean electricity. Accurate sunlight forecasts being developed by A*STAR researchers could greatly improve the performance of solar energy plants, making it a viable alternative to carbon-based sources of power.
A photovoltaic power plant can cover up to 50 square kilometers of the Earth’s surface and can generate up to a billion Watts of electricity. This capacity depends on the amount of sunlight at that location, so the ability to predict solar irradiance is crucial for knowing how much power the plant will contribute to the grid on any particular day.
“Forecasting is a key step in integrating renewable energy into the electricity grid,” says Dazhi Yang from A*STAR’s Singapore Institute of Manufacturing Technology (SIMTech). “It is an emerging subject that requires a wide spectrum of cross-disciplinary knowledge, such as statistics, data science, or machine learning.”
Yang, together with Hao Quan from the A*STAR Experimental Power Grid Centre and colleagues from the University of Tennessee at Chattanooga and the National University of Singapore, has developed a numerical approach to weather prediction that efficiently combines multiple datasets to improve the accuracy of solar irradiation forecasts.
Hourly changes in the atmosphere, annual changes in the distance between Earth and the Sun, or 10-yearly changes in the Sun’s internal cycles can all alter the amount of sunlight that reaches the Earth’s surface. These changes occur on very different time scales, and so conventional forecasting methods model variability at different timescales separately, which makes computer processing easier. However, these methods rely on a simple addition of forecasts, with no weighting that makes more use of better forecast sub-series. Moreover, the forecasts they generate are only accurate on the timescale of the original series.
Yang and the team developed a framework that reconciles the different timescales by forming a temporal hierarchy that aggregates forecasts obtained at different timescales, such as high-frequency, hourly data and low-frequency, daily data. “Temporal reconciliation is a type of ensemble forecasting model that forecasts the next day’s solar generation many times, separately, using data of different temporal granularities, hourly, two-hourly, and daily,” explains Yang. “These different forecasts are then combined optimally through statistical models to produce a final forecast.”
The researchers tested their numerical weather prediction method using data from 318 photovoltaic power plant sites in California over a year. Their temporal reconciliation method was shown to significantly outperform other numerical day-ahead forecasts.
UNSW professor Martin Green, who revolutionised photovoltaics, says sun’s power is ‘the best option out there’
By: Sophie Vorrath
The “father of PV” – University of New South Wales professor Martin Green – has become the first Australian to win the global energy prize from a shortlist that included Tesla’s Elon Musk.
UNSW said Green had been selected from 44 contenders from 14 countries by a committee of leading scientists to share the $820,000 prize with Russian scientist Sergey Alekseenko, an expert in thermal power engineering.
It said Green was honoured for revolutionising the efficiency and cost of solar photovoltaics, and making it the lowest-cost option for bulk electricity supply.
Green, the director of the Australian Centre for Advanced Photovoltaics, is a leading specialist in both monocrystalline and polycrystalline silicon solar cells.
In 1989, his team supplied the solar cells for the first photovoltaic system with an energy conversion efficiency of 20%. In 2014 he headed the development team that first demonstrated the conversion of sunlight into electricity with an efficiency of 40%.
Green also invented the PERC solar cell, which accounted for more than 24% of the world’s silicon cell manufacturing capacity at the end of 2017.
The research group he founded at UNSW – the largest university-based PV research group in the world – is broadly credited with driving the enormous reductions in costs in solar PV, largely through the work of Green’s students in establishing manufacturing centres in Asia.
“Not everyone would agree with that attribution,” said Green in an interview with RE on Friday, adding that Tesla’s Musk would have been his pick for the prize for his crucial work of putting electric vehicles on the agenda.
Green was keen to pay tribute to his UNSW solar stablemates, Zhengrong Shi, who left Australia to form Suntech Power in the US, and Stuart Wenham – the “Einstein” of the solar world, who died, aged 60, in December 2017.
“In particular, Stuart created this computer program that was a virtual production line,” Green told RE. “That overcame the language barrier in training hordes of Chinese engineers in setting up these [solar PV] production lines.”
Some 15 to 20 years later, and the global growth of solar PV – now the cheapest new form of energy generation – has soared beyond virtually all predictions.
“If you look at the figures from the last few years, growth has consistently stayed at around 40% a year,” Green said. “If it keeps growing at that rate, we’re looking at hitting a terawatt of solar production in 2024.
“Even if it slows to growth of 20% a year, we are on track to reach production levels of a TW a year in the late 2020s. And that’s the area where you can really start cutting greenhouse gases.”
And that’s what it’s all about – a cheap transition that does not cost more and in fact will likely deliver savings – although some people, and some governments, prefer to remain none the wiser. Which is why awards like this one are so important.
“I think [this is] a good opportunity to get across the message that things have changed with solar and that it’s the best option out there,” Green said. “That’s an important message to get out.
“There’s a growing consensus that we’re going to get most of our energy out of solar down the track. It’s not a matter having to help solar along. It’s not about removing the last remaining barriers – and getting out of the way of [renewable energy].”
Green said removing barriers often meant changing regulations to make them consistent with a solar type of future, as well as overcoming political resistance in places like Australia and the US.
By: Richard Piacentini
The Center for Sustainable Landscapes (CSL) generates all of its own energy and treats all storm and sanitary water captured on-site. An integral part of the Phipps visitor experience, it is the only building to meet four of the highest green certifications: the Living Building Challenge; LEED Platinum; WELL Building Platinum; and Four-Stars Sustainable SITES.
Everything is connected. That is to say, nothing happens in a vacuum. More than 2,000 years ago, Aristotle postulated that nature abhors a vacuum. Nature, like all things, work in systems, where everything is connected.
At Phipps Conservatory and Botanical Gardens, we have celebrated the beauty and importance of the natural world for 125 years and look to it now as inspiration for using systems thinking as a way to help solve the critical challenges that affect us all and provide us with solutions, such as adopting clean energy.
When facing a challenge, we have a tendency to address the symptoms,such as climate change and cancer, rather than the root causes which are often related to our disconnect from nature, our lifestyles and our unsustainable use of natural resources. Addressing symptoms is fragmental and only works in the short-term, as it never corrects the underlying cause. When we strive to understand the interconnectivity of whole living systems, we can appreciate our part within the larger natural and social systems in which we are nested. Only then we can catalyze real and meaningful long-term change.
In her work, regenerative business advocate Carol Sanford describes four paradigms for interacting with the world.
In the extractive model, it is all about “me”; the individual doesn’t care who or what they hurt to get what they want. The world is seen in fragments … there for the taking. This is colonialism.
In the less-bad model, we see a shift in thinking from “me” to “us”; an individual in this paradigm sees the world as fragmented but recognizes the fragments as interconnected and tries to stabilize them. This is where the environmental movement began, as exemplified by the “reduce, reuse, recycle” hierarchy and the first green building certification systems.
The do-good model is also about “us” but recognizes reciprocity; an individual in this model sees the world as fragmented but interconnected and tries to improve it. Some later iterations of green building programs fit this model.
The final paradigm is regenerative. It is about “us,” and seeing the world as a whole interconnected system rather than separate fragments. In a regenerative world, individuals move beyond thinking about themselves in isolation to see the larger social and natural systems that we collectively need to survive. This is the paradigm we need to adopt for the long-term health of ourselves and the planet.
When Phipps Conservatory and Botanical Gardens opened in 1893, most people thought there was no limit to the amount of natural resources we could use or the amount of pollution we could produce. In fact, people thought that humans would conquer nature. Our original conservatory is a great example of that type of mindset; a single-paned glass building designed to grow tropical plants in a temperate climate — from an energy perspective, this is one of the least efficient buildings imaginable.
In the 1990s, Phipps endeavored on a multi-phase master plan to renovate and expand the campus. Through each project, starting with building a Welcome Center, we identified the systemic implications of our actions and evolved our approach. We learned about LEED and discovered how much buildings contribute to the amount of energy and water we use and the pollution we produce.
For over a century, we had been talking about the importance of the environment, so why shouldn’t our buildings reflect that ethos?
This thinking informed the next projects in Phipps’ transformation: the Tropical Forest Conservatory, a giant glasshouse that has no greenhouse effect and is 100 percent passively cooled, and LEED Platinum production greenhouses. Next, we built the Center for Sustainable Landscapes (CSL) a net-positive energy and net-zero water building. The defining standard for the CSL is the Living Building Challenge, which is systems-based and embraces the idea of regenerative thinking. The CSL is remarkable, and five years later, it is still the only building in the world to meet the requirements of the Living Building Challenge, LEED Platinum, WELL Platinum and 4 Stars Sustainable SITES.
Too often, we focus on first costs and fail to align our actions with our values. Take the CSL for example: It cost about 20 percent more than a cheap big-box type of building and not much more than a typical office building; however, it is a much healthier place to work and, in the long run, it will last longer. It uses only a quarter of the energy of a building of comparable size and it generates all the energy it needs onsite without any combustion. It also frees us from the uncertainty of the market, easily outperforming a conventional building in the long run.
We recognize that we operate within living, dynamic, nested systems and that we make reciprocal, mutually beneficial interactions with the larger and lesser systems in which we are nested every day.
This systems-based way of thinking is used to review and design all of our projects, programming and operations. From adopting 100 percent renewable energy campus-wide in 2005 to defining new, socially responsible investment guidelines last year, Phipps is committed to understanding our role in nature and in developing the capacity in everyone we reach to make sustainability a defining component of their lives.
We will not conquer nature. Even if we could, it would be self-defeating, considering human and ecological health are one and the same. We must rethink the status quo and change.
It is not a technology problem and it is not a cost problem; we have the ability and means to solve many of our human and ecological health problems today. We have the capacity, but it is a question of whether we have the will to move beyond short-term symptomatic thinking and do what we know is right. From 2005 to 2016, Phipps reduced carbon dioxide emissions from our buildings by 56 percent per square foot, twice as much and twice as fast as the Paris Climate agreement.
When we have the focus and will to lead the way through regenerative systems thinking, our actions will provide a healthier planet for ourselves and all of the other species that share it.
By: Robbie Harris
The solar energy industry is getting better and better at producing power at lower cost than ever before but storing that energy for a rainy day remains a major roadblock. Batteries have their limitations, but scientists at Virginia Tech are taking a cue from how nature’s plants store energy.
Plants are actually nature’s storage systems for solar energy. They convert it into oxygen on a huge scale. Virginia Tech Chemistry Profess Amanda Morris and her team are working on a way to mimic how plants make that transformation, but instead of oxygen, they want to make methane.
“Methane is a chemical fuel that we use now,” notes Morris. “We can combust it in our boilers at home to heat our houses. There are buses that are powered on methane gas, so you can imagine that we can use that as a direct energy source.”
But, conventionally burning methane sends carbon dioxide into the air. So they’re working on capturing the CO-2 and converting it back to methane, to create an infinitely renewable cycle.
Plants come equipped with that transformation system that begins with oxidizing water, the first step in photosynthesis, but Morris is creating a new kind of molecular scaffold to do it.
“The way that I like to describe it is ‘molecular swiss cheese,’” says Morris. “You can picture a block of cheese with all these holes going through it. Replace the cheese with small chemicals and that’s what we’re working with.”
The goal is to achieve ‘artificial photosynthesis.’ And like the process of photosynthesis in plants, the gases in these methane power plants would be constantly recycled.
“So, we create a recyclable fuel stream. I think that would be a game changer.” But, she adds, “we also could change the way we make every day materials. I mean the plastic that’s on your phone; we could actually think about, how we make precursors to the polymers that are in these plastics. There’s a lot of places where this chemistry could potentially impact our daily lives.”
Morris says several companies are interested in this kind of CO-2 transformation. But her research will take more time.
She gives a shout out to the U.S. Department of Energy. She says she doesn’t mean to be political, but she hopes people will support the DOE for funding this kind of pure research because, this is what it takes to make these kinds of discoveries.
“We can’t necessarily say that our technology is going to be on the market in 10 years,” she says, “but we couldn’t say that about lithium batteries (at one point, either) and now they’re ubiquitous. And it’s really this fundamental research that the Department of Energy supports at universities that pushes our lives further.”
Morris presented her latest findings to DOE a few weeks ago and was told the results are impressive and that this is the first time a Nano molecular structure has shown promise for supporting artificial photosynthesis.
And that means there’s a chance it just might prove to be part of the missing link between creating solar energy and storing it in large quantities.
University of Erlangen-Nuremberg
Storing solar energy is the central challenge facing energy researchers. Alongside traditional solutions such as solar cells or batteries, creative chemical concepts for storing energy are paving the way for entirely new opportunities. Intramolecular reactions are making it possible to transform solar energy and store it in a singular molecule. This may form the basis for constructing energy-storing solar cells.
Electricity from a renewable energy source such as the sun or wind is only available when the wind blows or the sun shines, and it is extremely difficult to store any surplus electricity. New concepts are required—and researchers from the Department of Chemistry and Pharmacy at FAU are counting on chemical concepts for storing energy.
In two joint projects, the scientists are exploring new ideas for using molecules to store solar energy and are investigating molecules and processes that allow energy to be stored efficiently and released in a controlled manner when required. It is even conceivable that stored chemical energy could be converted directly into electrical energy.
The research is based on the so-called norbornadiene-quadricyclane storage system. Norbornadiene (NBD) and quadricyclane (QC) are hydrocarbons and have been under discussion among experts as potential candidates for storing solar energy for some time now. Under the influence of light, a reaction within the norbornadiene molecule is triggered, causing the molecule to transform into quadricyclane. The reaction produces an energy density similar to that of a high-performance battery. Thanks to this property, quadricyclane is also known as “solar fuel.”
The sub-project focusing on photochemical and magnetochemical storage and the release of solar energy in strained organic compounds is led by Prof. Dr. Dirk Guldi and Prof. Dr. Andreas Hirsch. The scientists are working on producing various new groups of NBD and QC derivatives. In addition, they are systematically investigating the influence of photosensitizers and electron acceptors as well as solvents and magnetic fields within this process. The long-term goal of the researchers is to create a closed system-fuel cycle for molecular storage systems.
Prof. Dr. Julien Bachmann, Prof. Dr. Jörg Libuda and Dr. Christian Papp are working together in the sub-project focussing on catalytic and electro-chemical release of solar energy stored in strained organic compounds. The scientists are developing new catalyst systems and electrodes that can be used to convert chemical energy directly into electrical energy. They intend proving the concept behind the functional principle using hybrid boundary surfaces with a suitable electronic structure, chemical structure and electrochemical stability.
The results of both sub-projects could form the basis for building an energy-storing solar cell. The electricity created by solar energy could be stored intelligently and used highly efficiently thanks to intramolecular reactions. | <urn:uuid:30517d0c-fcef-42fe-be45-d70c54740c94> | 3.890625 | 4,033 | Content Listing | Science & Tech. | 38.029279 | 95,489,213 |
Weekly Tropical Climate Note
ENSO neutral, but 50% chance of El Niño developing
The El Niño–Southern Oscillation (ENSO) remains neutral—neither El Niño nor La Niña. However, warming in the tropical Pacific Ocean and recent model outlooks suggest an increased likelihood of El Niño developing during the Australian spring. As a result, the Bureau's ENSO Outlook is at El Niño WATCH, meaning there is roughly a 50% chance of El Niño developing later in the year (double the climatological average). Much of Queensland and the Northern Territory typically experiences drier than average conditions in the lead up to, and early part of, the northern wet season (October to April) during El Niño.
See the Bureau's current ENSO Wrap-Up for more information.
Madden–Julian Oscillation likely to move over western Pacific Ocean and weaken
Cloudiness and rainfall has been enhanced over parts of South-East Asia and the north western tropical Pacific Ocean this past week. This is likely associated with a moderate to strong eastward moving pulse of the Madden–Julian Oscillation (MJO) which has been detected over these regions during this period.
Most international climate models indicate the MJO will continue its eastward progression into the Western Pacific and weaken. Before weakening, it could increase the likelihood of cloudiness and rainfall over the northwestern tropical Pacific Ocean and increase the risk of tropical cyclone development in this region.
The MJO generally has little effect on Australian climate at this time of year. See the Bureau's current MJO monitoring for more information.
An increase in cloudiness over the Indian subcontinent this past week indicated that some regions experienced an active monsoon this past week. Check the India Meteorological Department website for information about the Indian Monsoon.
Tropical cyclone activity continues over western north Pacific region
The Madden–Julian Oscillation also contributed to ongoing tropical cyclone activity across the western north Pacific Ocean this past week. The very intense typhoon Maria formed in the northwest Pacific on the 8 July and peaked at a maximum intensity equivalent to a category 5 tropical cyclone in Australia. Maria later weakened as it moved north westward, and made landfall on the eastern Chinese coast on 11 July at a strength comparable to an Australia category 3 system. Maria weakened rapidly to below tropical cyclone strength after crossing the Chinese coast, but generated heavy rainfall across Japan's southern Ryukyu Islands, northern Taiwan and parts of eastern China during its passage. Maria was an especially notable tropical typhoon due to its rapid intensification. Analysis by the United States Joint Typhoon Warning Centre indicated Maria strengthened from a category 1 to a category 5 hurricane (or equivalent tropical cyclone intensity at http://www.bom.gov.au/cyclone/about/intensity.shtml) in the space of just 24 hours on 5 July—one of the fastest developing systems ever recorded.
Tropical cyclone Son-Tinh, which reached tropical cyclone strength in the northwest Pacific Ocean on 17 July, is expected to impact parts of the Philippines, the Chinese island of Hainan, and Vietnam in the coming days. See the Japanese Meteorological Agency for more information.
Product code: IDCKGEW000 | <urn:uuid:d10520ff-ff97-4a4b-a61a-72671b3093bf> | 2.5625 | 670 | Knowledge Article | Science & Tech. | 26.047623 | 95,489,224 |
Activity for the week of 4 July-10 July 2018
- Info & Contacts
Activity for the week of 4 July-10 July 2018
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
|Karangetang||Siau Island (Indonesia)||New|
|Saunders||South Sandwich Islands (UK)||New|
|Sierra Negra||Isla Isabela (Ecuador)||New|
|Cleveland||Chuginadak Island (USA)||Ongoing|
|Ebeko||Paramushir Island (Russia)||Ongoing|
|Kilauea||Hawaiian Islands (USA)||Ongoing|
|Sheveluch||Central Kamchatka (Russia)||Ongoing|
Agung | Bali (Indonesia) | 8.343°S, 115.508°E | Elevation 2997 m
PVMBG reported that the eruption at Agung continued during 4-10 July. Sulfur dioxide flux was 1,400-2,400 tons/day on 3 July and 400-1,500 tons/day on 4 July. Satellite data acquired on 4 July indicated continuing lava effusion in the crater, with 4-5 million cubic meters effused in the past week. At 1220 an ash plume rose 2.5 km above the crater rim and drifted W. An event was detected at 2216, though an ash plume was not visible possibly due to poor viewing conditions. At 0047 on 5 July an ash plume rose at least 1 km and drifted W, and an event at 1633 produced an ash plume that rose 2.8 km and drifted E and W. A small event was detected on 6 July. According to BNPB a third Strombolian event occurred at 0522 on 8 July, generating an ash plume that rose 2 km. They noted that 4,415 evacuees were housed in 54 evacuation centers. An ash plume rose from the crater at 1120 on 9 July and drifted W. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.
Ambae | Vanuatu | 15.389°S, 167.835°E | Elevation 1496 m
The Vanuatu Meteorology and Geo-hazards Department reported that the recent eruption at Ambae’s Lake Voui was characterized by three phases of activity: Phase 1, September to late November 2017; Phase 2, late December 2017 to early February 2018; and Phase 3, February to April 2018. A fourth phase, which began on 20 June, consists of gas-and-steam emissions sometimes with ash; an ash plume on 1 July caused ashfall on the NW and W parts of the island and also on the NE part of Santo Island. The Alert Level remained at 2 (on a scale of 0-5), and the report reminded residents to stay at least 2 km away from the active crater.
Ibu | Halmahera (Indonesia) | 1.488°N, 127.63°E | Elevation 1325 m
Based on satellite images and PVMBG (a ground observer) notices, the Darwin VAAC reported that on 6 July an ash plume from Ibu rose to 2.1 km (7,000 ft) a.s.l. and drifted N. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.
Karangetang | Siau Island (Indonesia) | 2.781°N, 125.407°E | Elevation 1797 m
Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 4 July a diffuse ash plume from Karangetang rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted ENE. The Alert Level remained at 2 (on a scale of 1-4).
Krakatau | Indonesia | 6.102°S, 105.423°E | Elevation 813 m
PVMBG reported that during 4-5 July there were four ash-producing events at Anak Krakatau, each lasting between 30 and 41 seconds. Inclement weather conditions prevented an estimation of the ash-plume height from the event at 0522 on 4 July; ash plumes from events at 1409, 1425, and 1651 on 5 July rose 300-500 m above the crater rim and drifted N and NW. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.
Saunders | South Sandwich Islands (UK) | 57.8°S, 26.483°W | Elevation 843 m
Satellite data acquired during 1 January-9 July periodically (a few times a month) showed volcanic plumes originating from Michael on Saunders Island. A thermal anomaly was last detected on 3 April 2018.
Sierra Negra | Isla Isabela (Ecuador) | 0.83°S, 91.17°W | Elevation 1124 m
IG reported that a new magmatic intrusion at Sierra Negra was heralded by a M 5.2 earthquake recorded at 1830 on 4 July, and followed by 68 events between M 1.1 and 3.9. Seismic tremor began to be recorded at 1700 on 7 July by a station on the NE edge of the caldera. At the same time satellite data showed an increase in the intensity of the thermal anomaly on NW flank (it had decreased the previous day). Parque Nacional Galápagos staff confirmed strong incandescence in an area near the beach. A weak plume of water vapor and ash rose as high as 3.3 km (10,800 ft) a.s.l. and drifted SW and W. Tremor continued to be registered on 8 July, though the amplitude gradually decreased. Vapor-and-ash plumes reported by the Washington VAAC rose about 2 km (6,600 ft) a.s.l. and drifted SW, and the thermal anomaly remained intense. Gas clouds drifted 115 km W.
The current eruption at Sierra Negra began on 26 June and, according to news articles, prompted tourist restrictions and the evacuation of 50 residents.
Aira | Kyushu (Japan) | 31.593°N, 130.657°E | Elevation 1117 m
JMA reported that there were two events and three explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 2-9 July, with ash plumes rising as high as 1.3 km above the crater rim and material ejected as far as 1.1 km. Crater incandescence was sometimes visible at night. The Alert Level remained at 3 (on a 5-level scale).
Cleveland | Chuginadak Island (USA) | 52.825°N, 169.944°W | Elevation 1730 m
AVO reported that unrest at Cleveland continued during 4-10 July, though nothing significant was detected in seismic or infrasound data. Meteorological cloud cover often prevented views of the crater. Weakly elevated surface temperatures were identified in satellite images during 7 and 9-10 July; a small steam cloud was visible on 7 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Dukono | Halmahera (Indonesia) | 1.693°N, 127.894°E | Elevation 1229 m
Ebeko | Paramushir Island (Russia) | 50.686°N, 156.014°E | Elevation 1103 m
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 30 June-1 July that sent ash plumes as high as 3.2 km (10,500 ft) a.s.l. Satellite data showed ash plumes drifting 57 km SE on 1 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Fuego | Guatemala | 14.473°N, 90.88°W | Elevation 3763 m
INSIVUMEH and CONRED reported relatively quiet conditions at Fuego during 4-9 July characterized mainly by gas emissions and block avalanches on the flanks. During 7-8 July there was about one explosion detected every two hours, producing diffuse ash plumes that rose 500 m above the crater and drifted SW. Block avalanches descended the Seca (W), Cenizas (SSW), and Las Lajas (SE) drainages, while lahars were present in the El Jute (SE), Las Lajas, Cenizas, Taniluyá (SW), Seca, Mineral, and Pantaleón (W) drainages. Seismicity increased on 10 July. Explosions generated ash plumes that rose 2.3 km and drifted 12 km SE, causing ashfall in Morelia (9 km SW) and Panimaché (8 km SW). According to CONRED, as of 4 July, the number of people confirmed to have died due to the 3 June pyroclastic flows was 113, and 332 remained missing.
Kilauea | Hawaiian Islands (USA) | 19.421°N, 155.287°W | Elevation 1222 m
HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 4-10 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries. Fissure 22 produced spattering 50-80 m above its spatter cone and fed short lava flows that traveled NE on 4 July; weak spattering was visible form the cone the rest of the week.
Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes.
Fountaining at Fissure 8 continued; lava fountains rarely rose higher than the 55-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SE around Kapoho Crater. Occasional overflows sent small flows down the sides of the channel that did not extend beyond areas previously covered in lava in the upper part of the channel; overflows further down traveled beyond the flow-field boundary. Small brush fires were ignited from some of the overflows. A thermal map from 6 July showed that lava was not entering the ocean from the main channel and that the open channel ended about 2 km inland. Lava was flowing into the ocean at the N part of the broad flow front. Observations on 9 July indicated that a blockage had formed upstream of Kapoho Crater, and by 10 July a small lobe was moving around the W side of the crater.
Pacaya | Guatemala | 14.382°N, 90.601°W | Elevation 2569 m
INSIVUMEH reported that during 5-10 July Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 30 m above the crater rim. White gas plumes drifted SW. A lava flow originating from Mackenney Crater traveled 500 m down the N flank during 7-8 July, reaching the volcano’s base.
Sabancaya | Peru | 15.787°S, 71.857°W | Elevation 5960 m
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 22 per day during 2-8 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted 30 km S, SE, and E. The MIROVA system detected nine thermal anomalies, and on 3 July the sulfur dioxide gas flux was high at 4,715 tons/day. The report noted that the public should not approach the crater within a 12-km radius.
Santa Maria | Guatemala | 14.757°N, 91.552°W | Elevation 3745 m
INSIVUMEH reported that during 5-10 July explosions at Santa María's Santiaguito lava-dome complex generated ash plumes that rose 200-700 m and drifted SW and W. Local ashfall was reported. Avalanches of material descended the SE and W flanks of the lava dome.
Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Elevation 3283 m
KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 4-5 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Weekly Reports Archive
|Ambang||Gaua||Maly Semyachik||Sarychev Peak|
|Anatahan||Great Sitkin||Manda Hararo||Semeru|
|Apoyeque||Guagua Pichincha||Maroa||Seulawah Agam|
|Axial Seamount||Hokkaido-Komagatake||Metis Shoal||Slamet|
|Azul, Cerro||Home Reef||Misti, El||Soputan|
|Balbi||Huila, Nevado del||Monowai||Soufriere Hills|
|Bamus||Hunga Tonga-Hunga Ha'apai||Montagu Island||Soufriere St. Vincent|
|Banda Api||Ibu||Moyorodake [Medvezhia]||South Sarigan Seamount|
|Barren Island||Iliamna||Myojinsho||St. Helens|
|Bezymianny||Inielika||Negra, Sierra||Sulu Range|
|Callaqui||Kadovar||NW Rota-1||Tair, Jebel at|
|Campi Flegrei del Mar di Sicilia||Kanaga||Nyiragongo||Talang|
|Chillan, Nevados de||Kavachi||Palena Volcanic Group||Tenerife|
|Concepcion||Kick 'em Jenny||Peuet Sague||Tolbachik|
|Descabezado Grande||Kolokol Group||Rabaul||Ulawun|
|Dieng Volcanic Complex||Korovin||Ranakah||Unknown Source|
|Epi||Kverkfjoll||Rincon de la Vieja||Witori|
|Erta Ale||Lamongan||Ritter Island||Yasur|
|Etorofu-Yakeyama [Grozny Group]||Lanin||Ruang||Zavodovski|
|Fernandina||Lengai, Ol Doinyo||Ruiz, Nevado del||Zubair Group|
|Fournaise, Piton de la||Lewotolo||Salak|
|Fourpeaked||Little Sitkin||San Cristobal|
News Feeds and Google Placemarks
The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website.
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The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
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RSS and CAP Feeds
An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.
At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.
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Google Earth Placemarks
A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.
Acronyms and Abbreviations
a.s.l. - above sea level
CENAPRED - Centro Nacionale de Prevencion de Desastres (México)
COSPEC - Correlation Spectrometer
CVGHM (formerly VSI) - Center of Volcanology and Geological Hazard Mitigation
GMS - Geostationary Meteorological Satellite
GVO - Goma Volcano Observatory
ICE - Instituto Costarricense de Electricidad (Costa Rica)
IG - Instituto Geofísico (Ecuador)
IGNS - Institute of Geological and Nuclear Sciences (New Zealand) - now GNS Science
INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)
INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)
INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)
INGV-CT - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (Italy)
INSIVUMEH - Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (Guatemala)
IRD - Institut de Recherche pour le Développement (France)
KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department
M - magnitude
METEOSAT - Meteorological Satellite
MEVO - Mount Erebus Volcano Observatory
MWO - Meteorological Watch Office
NOTAM - Notice to Airmen
OVDAS - Observatorio Volcanologico de los Andes del Sur (Chile)
ONEMI - Oficina Nacional de Emergencia - Ministerio del Interior (Chile)
OVPDLF - Observatoire Volcanologique du Piton de la Fournaise (France)
OVSICORI-UNA - Observatorio Vulcanologico y Sismologico de Costa Rica, Universidad Nacional (Costa Rica)
PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)
RSAM - Real-time Seismic Amplitude Measurement
RVO - Rabaul Volcano Observatory
SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)
SIGMET - Significant Meteorological Information
SNET - Servicio Nacional de Estudios Territoriales (El Salvador)
SVERT - Sakhalin Volcanic Eruption Response Team (Russia)
UTC - Coordinated Universal Time
VAAC - Volcanic Ash Advisory Center
VAFTAD - Volcanic Ash Forecast Transport And Dispersion
VRC - Volcano Research Center (Japan) | <urn:uuid:2700e637-df0b-43ec-b751-ee45abdc1ce5> | 2.75 | 5,715 | Content Listing | Science & Tech. | 42.24869 | 95,489,229 |
Received date: March 08, 2016; Accepted date: March 21, 2016; Published date: March 28, 2016
Citation: Hu D, Zhang Z, Guo B, et al. The Development of PM2.5 Standard Aerosol Generator Based on PGSS Method. J Sci Ind Metrol. 2016, 1:10. doi: 10.4172/2472-1948.100010
The generation of standard aerosol is of vital importance for the PM2.5 monitors calibration. In this work, a PM2.5 standard aerosol generator with high-pressure mixing kettle, crystal kettle and nozzle was developed based on the Particle from gas saturated solutions (PGSS) approach. The preliminary experiment on the generator showed that more than 90% of the aerosol particles were smaller than 2.5 μm in diameter. This work can provide a theoretical basis for the PM2.5 monitors calibration.
PM2.5; Aerosol generator; PGSS; Mixing kettle
The standard aerosol generation is important for the PM2.5 monitors calibration. Various techniques are known for aerosol generation such as Atomization method, Fluidized Bed method and Agglutination method . However, the limitations of these traditional methods must be focused that Atomization method could only be applied to powder materials dissolved easily in liquid , the Fluidized Bed method is well known for the unevenly distributed aerosol particles , and the Agglutination method is only applicable to the particular materials with reaction characteristic . A new approach is therefore needed in the generation of PM2.5 standard aerosol.
The generation of nano-micron particles based on supercritical fluids, especially the PGSS approach, has made a great progress in recent years. PGSS involves first dissolving the supercritical fluid in the molten liquid to form the saturated solution, then spraying saturated solution through the nozzles, causing the nano-micron particles to be generated . With the advantages of the lower operating pressure, less dosage of CO2 and no organic solvent, etc., compared with other supercritical fluids technologies, such as Rapid Expansion of Supercritical Solutions and Supercritical Anti-Solvent , PGSS has been widely applied. PGSS was firstly introduced by Weidner in 2003 who chronically committed to the research of the micronization of polyethylene glycol [8,9]. Tandya et al. had generated cyclosporine particles for 1 μm using PGSS. Wang had generated menthol / wax microcapsule from 2 μm to 30 μm. These above showed that PGSS is a better method for the PM2.5 standard aerosol generation with the advantage of controlling the diameter and distribution of the particles by only adjusting the temperature and pressure of the mixing kettle. Therefore, a PM2.5 standard aerosol generation process based on the PGSS was developed, as well as a PM2.5 standard aerosol generator was designed in this paper.
The PM2.5 standard aerosol generator based on PGSS is shown in Figure 1.
Figure 1: Schematic diagram of PM2.5 standard aerosol generator based on PGSS. 1 - CO2 cylinder; 2, 6, 8, 10, 11, 12, 14, 15, 16, 17, 19, 20, 21, 27 - Valve; 3 - Purifier; 4 - Flow Meter; 5 - Refrigeration Equipment; 7 - High - Pressure Pump; 9 - Buffer Kettle; 13 - High - Pressure Mixing Kettle; 18 - High - Pressure Mixing KettleII; 22 - Buffer Kettle; 23 - Flow Meter; 24 - Crystal Kettle; 25 - Metering Pump; 26 - Solution Tank.
1. The CO2 from the CO2 cylinder is fed through the flow system, the value 27 is kept opening to exhaust, and then the CO2 cylinder valve should be closed before the experiment.
2. Materials packed in high-pressure mixing kettle 13 or 18, are heated using the thermostat in a temperature higher than the fusion point of them after a predetermined period of time to melt them.
3. Opening the refrigeration equipment to preset to the cooling temperature, then the relevant valves 2, 6, 8, 10, 11 (or 15) are turned on. The CO2 from the CO2 cylinder passes through purifier, refrigeration equipment, high-pressure pump in turn resulting in a supercritical state, and then flows into highpressure mixing kettle.
4. The supercritical carbon dioxide in high - pressure mixing kettle is maintained at the preset pressure and temperature for 0.5 h to 5 h so as to mix well with the melted materials.
5. Upon opening the valve 16, the supercritical carbon dioxide is introduced through bypass pipeline into the nozzle, then the valve 14 or 19 is turned on that the mixture from highpressure mixing kettle is sprayed through the nozzle with a decompression and expansion, to avoid the blocking in the generation of PM2.5 aerosol, and the supercritical carbon dioxide inside the nozzle designed this work can further mixes with the melted materials, as well as further disperses small droplets. Then the aerosol generated gets through the valve 27 into subsequent equipment.
The PM2.5 standard aerosol generator based on PGSS consisted of the following main components: CO2 cylinders, purifier, refrigeration equipment, and high - pressure pump, thermostat, two high-pressure mixing kettle, crystal kettle, nozzles. The last three components were designed as the main task in this work. This design can meet with the requirement of the temperature and pressure according to Chinese Standards. The others were selected from standard component which could also meet with the experiment requirements.
The design of high - pressure mixing kettle
The design parameters of the high - pressure mixing kettle were as follows: maximum working pressure of 15 MPa, maximum design temperature of 100°C, and inner diameter of 30 mm. According to these design parameters, the high-pressure mixing kettle was designed and calculated according to Chinese Standard TSG R0004 - 2012 and Chinese Standard GB150-2011 . The thickness of the shell, the maximum working pressure and the thickness of the head can be calculated using the formula 1 - 3, respectively. The structure of the high - pressure mixing kettle was shown in Figure 2.
Where,δ is shell thickness; Di is inner diameter; [σ]t is allowable stress of material; φ is seam coefficient; pc is design pressure, δe is effective thickness, DG is the center diameter under the pressing force, δp is thickness of the head, and K is structure coefficient of the head (Figure 2).
The design of crystal kettle
The design parameters of the crystal kettle were as follows: maximum working pressure of 15 MPa and inner diameter of 55 mm. The crystal kettle structure was also designed up to China's Nation Standard and Profession Standard , for calculating the thickness of the shell and the head obtained from the Equation (1) and (2), respectively, it was shown in Figure 3.
Figure 3: Diagram of crystal kettle. 1 - Flat Head; 2 - Flat Gasket; 3 – Nut; 4 - Stud Bolt; 5 - Sealing Gasket; 6 - Kettle Body; 7, 9 - Supercritical Fluid Inlet Connection; 8 - Mixture Entrance; 10 – Nozzle; 11 - Pressure Strip; 12 – Window; 13 - Sintered Plate Fixed Ring; 14 - Sintered Plate; 15 - Emptying Tube
The design of nozzle
The nozzle shown in Figure 4 is a coaxial three - channel internal - mixing size - adjusting nozzle. The main components of it include the lock nut, seal ring, taper sleeve and core. The taper sleeve was designed according to Chinese Standard JB4732 - 2005 . The thickness of the taper sleeve can be calculated according to the formula 6. The thread stress can be calculated according to the formula 7. The spraying of mixture was a critical step in the generation of PM2.5 aerosol, and the size of aerosol particles was affected by adjusting the nozzle outlet for the clearance size which would decrease as the taper sleeve rising owing to the certain angle between the core and taper sleeve. It meant that different diameters were achieved in one nozzle rather than in several different conventional nozzles. This work not only greatly reduced the number of nozzles and the manufacturing cost, but also was convenient to replace the nozzles frequently during the experiment work.
Where, Di is the inner diameter of taper sleeve, Do is the outer diameter of taper sleeve, Pc is the design pressure, K1 is load combination factors, Sm is stress intensity, δ1 is the thickness of taper sleeve, σm is the thread stress, and F is axial load.
Manufacturing and Testing of the PM2.5 Standard Aerosol Generator
Manufacturing of the equipment
The PM2.5 standard aerosol generator was manufactured by Nantong Huaan Chaolinjie Co. LTD. High-pressure mixing kettle, crystal kettle and the PM2.5 standard aerosol generator assembled are shown in Figures 5a-5c, respectively.
Testing of the equipment
The experiment was firstly carried out with the high-pressure mixing kettle keeping at 15 MPa and 90°C for 90 min. Then mixture was sprayed through the nozzle into the crystal kettle which was maintained in 5.6 MPa at ambient temperatures keeping the sprayed time for 120 min. In this research, the particles of polyethylene glycol 8000 were generated using PGSS method, collected on the 1000 mesh sieve in Figure 6a, and the Micro-morphology of them was then investigated by the scanning electron micrograph (SEM) shown in Figure 6b.
Subsequently experiment was conducted with the high-pressure mixing kettle keeping at 20 MPa and 80°C for 90 min. Then mixture was sprayed through the nozzle into the crystal kettle which was maintained in 5.6 MPa at ambient temperatures keeping the sprayed time for 120 min. The particles of polyethylene glycol 8000 generated using PGSS method were shown in Figures 7a and 7b.
As shown in Figures 6b and 7b, the particles were small and uniform for overall distribution with more than 90% smaller than 2.5 μm in diameter, and the others were larger than 2.5 μm because a large number of tiny particles aggregated on the mesh sieve in the colleting process. In order to solve the particle aggregation problem, the crystal kettle would be equipped with electrostatic ion-generator to electrify the particles and produce repulsive force so as to overcome the effects of van der Waals forces to avoid aggregation, and the aerosol was directly sprayed into the aerosol spectrometer to detect the aerodynamic diameter of aerosol particles.
In this paper, the PM2.5 standard aerosol generator based on the PGSS was firstly designed and manufactured. And the results of preliminary experiments, in which the nano-micron particles were generated with polyethylene glycol 8000 as the raw material, showed that more than 90% of the aerosol particles were smaller than 2.5 μm in diameter, this result is similar to the Atomization method with diameter in the range of 1.3 μm - 5.8 μm , and the others were larger than 2.5 μm due to the aggregation of tiny particles on the mesh sieve in the collecting process. And further study on the generation process conditions is still required in subsequent experiments to realize steady generation of standard PM2.5 aerosol and make the device as a steady source of PM2.5 aerosol. PM2.5 standard aerosol generator will have great significance for the realization of PM2.5 monitors testing and calibration.
The work reported here was supported by the Shandong Institute of Metrology and the Department of Shandong province. We express our grateful thanks to the Science and Technology Development Plan Project of Shandong Province (2014GSF117026) and Project of Shandong Province Higher Educational Science and Technology Program (J13LM08) for their financial support.
All Published work is licensed under a Creative Commons Attribution 4.0 International License
Copyright © 2018 All rights reserved. iMedPub LTD Last revised : July 19, 2018 | <urn:uuid:dd403b96-c8f5-47cb-b441-d07a76f3d0b9> | 2.5625 | 2,563 | Academic Writing | Science & Tech. | 49.912839 | 95,489,251 |
This has the capability of being a game changer, especially for the Government! Can you imagine having the capability to cloak macro objects underwater and in the air! While we believe this to be most likely man made technology it begs the questions….could its genesis be with alien technology. Educating Humanity is happy to bring you this news breaking story!
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Invisibility Rug Hides Large Objects
Objects large enough to be seen with the naked eye have been swept under an ‘invisibility carpet’ for the first time.
Invisibility cloaks were proposed in 2006, and prototypes that can shield objects for certain wavelengths of light have since been built. However, until now, physicists have been unable to fabricate a cloak that could hide macroscopic items at visible wavelengths. Two independent groups have now achieved this feat, by building transparent ‘carpet cloaks’, made from calcite crystals, that lie over the object to be hidden.
Carpet cloaks render covered objects invisible by bending light rays as they enter the cloak and then when they exit it — after they have bounced off the hidden object. The light is deviated in such a way that the rays seem to have been reflected directly from the ground underneath the object — as though the object was not there.
To build such a cloak you need a material that will bend the incoming and outgoing light rays by different amounts — determined by the dimensions of the object underneath, explains Baile Zhang, an optical engineer at the Singapore–MIT Alliance for Research and Technology (SMART) Centre in Singapore, who designed one of the cloaks. Calcite is perfect for the job because the speed at which polarized light passes through it depends on the crystal’s orientation. So by sticking together two pieces of crystal, it is possible to create a cloak that bends incoming and outgoing light by the desired amount.
“The fact that calcite’s optical properties depend on orientation is usually a disadvantage in making devices, but I realized we could actually exploit it to our advantage,” says Baile Zhang.
Baile Zhang and his colleagues have built a calcite carpet-cloak that can shield a steel wedge that is 38 millimetres long and 2 millimetres high from red, green and blue visible light3. The team designed their cloak to work under water. “I think that governments could make a lot of use out of a cloak that can hide objects on the seabed — although I won’t speculate on exactly what they may want to hide,” says team member George Barbastathis, a mechanical engineer also at the SMART Centre.
By contrast, an independent group led by physicists Shuang Zhang at the University of Birmingham, UK, and John Pendry from Imperial College London has built a calcite cloak that can work in air, hiding objects a few centimetres high. Pendry was one of the first scientists to propose how an invisibility cloak might work. The team, however, were unable to comment as their research has been submitted for publication and is under embargo.
Both of the calcite carpet-cloaks are much cheaper to make than previous invisibility carpets, which were built using intricately fabricated silicon microstructures and could only conceal microscale objects, says Baile Zhang. “Because they were so difficult and expensive to construct they are difficult to scale up,” he says. But the calcite cloak uses naturally occurring materials that cost only about US$1,000 to make and are easy to manipulate. “It’s not quite easy enough to make at home, but it’s not too far off,” says Baile Zhang.
Michal Lipson, a physicist at Cornell University in Ithaca, New York, says “one of the real worries about cloaking has been that people would only be able to cloak microsize objects.” Lipson adds that creating macroscopic devices now shows that “we are close to cloaking objects that we are familiar with in every day life”. | <urn:uuid:0d8d6ddd-0efd-44c2-b6a5-d31b27789eca> | 3.015625 | 861 | News Article | Science & Tech. | 40.218769 | 95,489,285 |
It’s a potential breakthrough in the fight against plastic pollution—an enzyme that can digest plastic that is commonly found polluting our environment.
The discovery could oneday result in a recycling solution that can process millions of tonnes of plastic, made from polyethylene terephthalate (also known as PET), which currently persists in the environment for hundreds of years. The research was led by teams at the University of Portsmouth and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), with the results being published in the National Academy of Sciences (PNAS).
The findings follow the discovery of an enzyme that had evolved to digest PET plastic, which is often used in the production of plastic bottles, food containers,and even fibers in clothes. Professor John McGeehan from the University of Portsmouth and Gregg Beckham at the NREL studied the crystal structure of this enzyme to understand how it works.
During the study, the team accidentally engineered a mutant version that is even better at degrading the plastic than the one that has evolved in nature.
The researchers are now working on further improving the effectiveness of the enzyme so it can be applied to industrial uses, where it may break down plastic in a fraction of the time.
McGeehan, director of the Institute of Biological and Biomedical Sciencesin the School of Biological Sciences at Portsmouth, said: “We can all play a significant part in dealing with the plastic problem, but the scientific community who ultimately created these ‘wonder materials’ must now use all the technology at their disposal to develop real solutions.”
The breakthrough came through the examination of the structure of the enzyme that had evolved in nature and was thought to have been discovered in a recycling site in Japan. The aim was to understand how the enzyme had evolved and to see if it might be possible to improve it. During the study, however, the team accidently engineered an enzyme that was even better at breaking down PET plastic.“Serendipity often plays a significant role in fundamental scientific research and our discovery here is no exception,” McGeehan said.
“Although the improvement is modest, this unanticipated discovery suggests that there is room to further improve these enzymes, moving us closer to a recycling solution for the ever-growing mountain of discarded plastics.”
The research team can now apply the tools of protein engineering and evolution to continue to improve the enzyme. The research also revealed that the enzyme can also degrade olyethylene furandicarboxylate, or PEF, a bio-based substitute for PET plastics that is being hailed as a replacement for glass beer bottles.
McGeehan said: “The engineering process is much the same as for enzymes currently being used in bio-washing detergents and in the manufacture of biofuels –it’s well within the possibility that in the coming years we will see an industrially viable process to turn PET and potentially other substrates like PEF, PLA, and PBS, back into their original building blocks so that they can be sustainably recycled.” | <urn:uuid:a4dab7e8-5fec-4f94-84e9-fd9848993e24> | 3.78125 | 638 | News Article | Science & Tech. | 27.067135 | 95,489,331 |
Landscape Evolution Observatory
The Earth system consisting of air, water, soil, plants and microbes is a complex, interacting system. How do physical and biological processes interactively control the evolution of landscapes? How is water flowing through landscapes influenced by their evolution in time, and by climate change? How do biological communities organize and respond to landscape evolution and environmental change? These are some examples of the most important and complicated Earth system science questions reflecting the complex nature of the Earth system with so many interactive parts And they’re ones that the Landscape Evolution Observatory, a physical model to simplify the complex interactions by controlling parts of the system, was designed to help answer.
The Landscape Evolution Observatory (LEO) is the world’s largest laboratory experiment in the interdisciplinary Earth sciences. The experiment consists of three artificial landscapes contained within elaborate steel structures and located inside three adjacent bays within the University of Arizona – Biosphere 2. The landscapes are designed as experimental replicates; each has dimensions of 30-m length, 11-m width, an average slope of 10°, and is filled to a uniform depth of 1 m with crushed basalt rock that was extracted from a volcanic crater in northern Arizona. In their initial state, the landscapes consist of approximately 500 metric tons (more than 1 million pounds) of the crushed rock, which has a loamy sand texture. This initial condition will allow scientists to observe each step in the landscapes’ evolution—from purely mineral and abiotic substrate to living, breathing landscapes that will ultimately support microbial and vascular plant communities
Those observations are made possible by the array of more than 1800 sensors and sampling devices that are installed on, within, or above each landscape. The sensors enable monitoring of water, carbon, and energy cycling processes, and the physical and chemical evolution of the landscape at sub-meter to whole-landscape scales. As the soil, topography, and biological communities evolve to increasingly complex states, scientists will be able to document how those changes affect water, carbon, and energy cycling within the landscape, and between the landscape and the atmosphere.
Research at LEO will advance our understanding of how climate change may impact water resources and ecosystems in arid environments. This understanding will result from iterations of well-designed physical experiments with LEO and virtual experiments with mathematical models of coupled ecohydrological processes. Since LEO resides within the climate controlled Biosphere 2 facility, researchers can perform manipulative experiments to examine how the water, soil, plant, and microbes respond to diverse scenarios of climate (air temperature and rainfall) The climate control capabilities, well-defined system properties, and network of sensors make LEO an exceptional platform for developing and testing mathematical models (conceptual models) that simulate this ecohydrological responses—the types of models that can be used to infer how water resources and ecosystems in real landscapes may be impacted by ongoing and future climate change.
Post-wildfire landscape change and erosional processes from repeat terrestrial lidar in a steep headwater catchment, Chiricahua Mountains, Arizona, USA . DeLong, S.B., Youberg, A.M., DeLong, W.M., Murphy, B.P. (2018): Geomorphology 300: 13-30.
Effects of differential hillslope‐scale water retention characteristics on rainfall–runoff response at the Landscape Evolution Observatory . van den Heuvel, D. B., Troch, P. A., Booij, M. J., Niu, G.‐Y., Volkmann, T. H. M., Pangle, L. A. (2018): Hydrological Processes 32(13): 2118–2127.
CO2 diffusion into pore spaces limits weathering rate of an experimental basalt landscape . van Haren, J., Dontsova, K., Barron-Gafford, G. A., Troch, P. A., Chorover, J., Delong, S. B., Breshears, D. D., Huxman, T. E., Pelletier J. D., Saleska, S. R., Xeng, X., and Ruiz, J. (2017): Geology 45(3): 203-206.
The mechanistic basis for storage-dependent age distributions of water discharged from an experimental hillslope . Pangle, L. A., Kim, M. Cardoso, C., Lora, M., Meira Neto, A. A., Volkmann, T. H. M., Wang, Y., Troch, P. A., and Harman, C. J. (2017): Water Resources Research 53: 2733–2754.
Methanotrophic bacterial diversity in two diverse soils under varying land-use practices as determined by high-throughput sequencing of the pmoA gene . Sengupta, A. and Dick, W. A. (2017): Applied Soil Ecology 119: 35-45.
Pore water chemistry reveals gradients in mineral transformation across a model basaltic hillslope . Pohlmann, M., Dontsova, K., Root, R., Ruiz, J., Troch, P., and Chorover, J. (2016): Geochemistry, Geophysics, Geosystems 17(6): 2054–2069.
The Effects of Rain on Elemental Transport in Soils . Schoenfeld, L.K., Hunt, E.A., Dontsova, K.M. (2016): STAR (STEM Teacher and Researcher) Program Posters.
Between control and complexity: opportunities and challenges for marine mesocosms . Sagarin, R.D., Adams, J., Blanchette, C.A., Brusca, R.C., Chorover, J., Cole, J.E., Micheli, F., Munguia-Vega, A., Rochman, C.M., Bonine, K., van Haren, J. and Troch, P.A. (2016): Frontiers in Ecology and the Environment 14(7): 389–396.
Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations . Sengupta, A. Wang, Y., Meira-Neto, A.A., Matos, K.A., Dontsova, K., Root, R., Neilson, J.W., Maier, R.M., Chorover, J., and Troch, P.A. (2016): Journal of Visualized Experiments 115: e54536.
Multiresponse modeling of variably saturated flow and isotope tracer transport for a hillslope experiment at the Landscape Evolution Observatory . Scudeler, C., Pangle, L., Pasetto, D., Niu, G.-Y., Volkmann, T., Paniconi, C., Putti, M., and Troch, P. (2016): Hydrology and Earth System Sciences 20(10): 4061-4078.
Transit time distributions and StorAge Selection functions in a sloping soil lysimeter with time-varying flow paths: Direct observation of internal and external transport variability . Kim, M., Pangle, L. A., Cardoso, C., Lora, M., Volkmann, T. H. M., Wang, Y., Harman, C. J., and Troch, P. A. (2016): Water Resources Research 52(9): 7105-7129.
Testing the hybrid-3-D hillslope hydrological model in a controlled environment . Hazenberg, P., Broxton, P., Gochis, D., Niu, G.-Y., Pangle, L. A., Pelletier, J. D., Troch, P. A., and Zeng X. (2016): Water Resources Research 52(2): 1089–1107.
Impact of sensor failure on the observability of flow dynamics at the Biosphere 2 LEO hillslopes . Pasetto, D., Niu, G.-Y., Pangle, L., Paniconi, C., Putti, M., Troch, P. A. (2015): Advances in Water Resources 86: 327-339.
Seven Anion Comparison for the Center and West Hill Slope Systems in the Landscape Evolution Observatory (LEO) Project . Corrigan, S.C., Hunt, E.A., Dontsova, K.M. (2015): STAR (STEM Teacher and Researcher) Program Posters.
Mineral nutrient mobilization by plants from rock: influence of rock type and arbuscular mycorrhiza . Burghelea, C., Zaharescu, D. G., Dontsova, K., Maier, R., Huxman, T., Chorover J. (2015): Biogeochemistry 124(1): 187-203.
The Landscape Evolution Observatory: A large-scale controllable infrastructure to study coupled Earth-surface processes . Pangle, L.A., DeLong, S.B., Abramson, N., Adams, J., Barron-Gafford, G.A., Breshears, D.D., Brooks, P.D., Chorover, J., Dietrich, W.E., Dontsova, K., Durcik, M., Espeleta, J., Ferre, T.P.A., Ferriere, R., Henderson, W., Hunt, E.A., Huxman, T.E., Millar, D., Murphy, B., Niu, G-Y., Pavao-Zuckerman, M., Pelletier, J.D., Rasmussen, C., Ruiz, J., Saleska, S., Schaap, M., Sibayan, M., Troch, P.A., Tuller, M., van Haren, J., Zeng, X. (2015): Geomorphology 244: 190-203.
Incipient subsurface heterogeneity and its effect on overland flow generation – insight from a modeling study of the first experiment at the Biosphere 2 Landscape Evolution Observatory . Niu, G.-Y., Pasetto, D., Scudeler, C., Paniconi, C., Putti, M., Troch, P. A., DeLong, S. B., Dontsova, K., Pangle, L., Breshears, D. D., Chorover, J., Huxman, T. E., Pelletier, J., Saleska, S. R., and Zeng, X. (2014): Hydrology and Earth System Sciences 18(5): 1873-1883.
Flow and transport modeling of a tracer isotope experiment at B2 LEO using integrated and distributed multisensor observation data . Scudeler, C., Pangle, L., Pasetto, D., Niu, G-Y., Paniconi, C., Putti, M., Troch, P. (2014): Abstract H13E-1165 presented at 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 Dec.
Rapid CO2 consumption during incipient weathering of a granular basaltic hillslope in the Landscape Evolution Observatory, Biosphere 2 . Ruiz, J., Van Haren, J., Dontsova, K., Barron-Gafford, G., Troch, P., Chorover J. (2014): Abstract V23A-4778 presented at 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 Dec.
Hillslope-scale experiment demonstrates the role of convergence during two-step saturation . Gevaert, A.I., Teuling, A.J., Uijlenhoet, R., DeLong, S.B., Huxman, T.E., Pangle, L.A., Breshears, D.D., Chorover, J., Pelletier, J.D., Saleska, S.R, Zeng, X., Troch, P.A. (2014): Hydrology and Earth System Sciences 18: 3681-3692.
Monitoring and Modeling Water, Energy and Carbon Fluxes at the Hillslope Scale in the Landscape Evolution Observatory . Troch, P., Barron-Gafford, G., Dontsova, K., Fang, Y., Niu, G.-Y., Pangle, L., Tuller, M., Van Haren, J. (2014): Abstract H43L-1128 presented at 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 Dec.
Reactive Transport Modelling of Mineral Evolution in the Biosphere 2 Hillslope Experiment . Wu, R., Niu, G.-Y., Steefel, C., Paniconi, C., Chorover, J., Dontsova, K., Troch, P. (2014): Abstract H53A-0843 presented at 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 Dec.
Impact of organic carbon on weathering and chemical denudation of granular basalt . Dontsova, K., Zaharescu, D., Henderson, W., Verghese, S., Perdrial, N., Hunt, E., Chorover, J. (2014): Geochimica et Cosmochimica Acta 139: 508–526.
Breakthroughs in Lab Experiments . Peter Troch (2013): GIWS Distinguished Lecture Series.
Precipitation pulse dynamics of carbon sequestration and efflux in highly weatherable soils . Barron-Gafford, G., Minor, R., Van Haren, J.L., Dontsova, K., Troch, P.A. (2013): Abstract EP13C-0879 presented at 2013 Fall Meeting, AGU, San Francisco, CA, 9-13 Dec.
Hydrologic discovery through controlled experimentation, data analysis, and numerical and analytical modeling at the Landscape Evolution Observatory (Invited) . Troch, P. A., Gevaert, A., Smit, Y., Niu, G.-Y., Nakolan, L., Kyzivat, E. (2013): Abstract H11C-1167 presented at 2013 Fall Meeting, AGU, San Francisco, CA, 9-13 Dec.
Hysteresis of soil moisture spatial heterogeneity and the “homogenizing” effect of vegetation . Ivanov, V.Y.,Fatichi, S., Jenerette, G.D., Espeleta, J.F., Troch, P.A., Huxman, T.E. (2010): Water Resources Reasearch 46(9): W09521.
The Hills are Alive: Interdisciplinary Earth Science at Biosphere 2 . Huxman, T., Troch, P., Chorover, J., Breshears, D.D., Saleska, S., Pelletier, J., Zeng, X. (2009): EOS 90(14): 120.
Solid phase evolution in the Biosphere 2 hillslope experiment as predicted by modeling of hydrologic and geochemical fluxes . Dontsova, K., Steefel, C.I., Desilets, S., Thompson, A., Chorover, J. (2009): Hydrology and Earth System Sciences 13: 2273-2286..
Hillslope hydrology under glass: Confronting fundamental questions of soil-water-biota co-evolution at Biosphere 2 . Hopp, L., Harman, C., Desilets, S. L.E., Graham, C. B., McDonnell, J. J., Troch, P. A. (2009): Hydrology and Earth System Sciences 13: 2105–2118. | <urn:uuid:05691ca8-c4b1-4d7b-a094-831f2840d332> | 3.796875 | 3,361 | About (Org.) | Science & Tech. | 65.173867 | 95,489,380 |
| Leptogenys kitteli|
From Chiu, Mankin and Lin 2011: Leptogenys kitteli (Mayr) (Hymenoptera: Formicidae) is a species of commonly observed but little studied army ants that hunt in groups in broadleaf and coniferous forests in lowland and hilly areas of Taiwan. These ants live in soil or litter and move their nests frequently.
Keys including this Species
Distribution based on Regional Taxon Lists
Check distribution from AntMaps.
Distribution based on specimens
From the abstract of Chiu, Mankin and Lin 2011: "Individual Leptogenys kitteli (Hymenoptera: Formicidae) workers produce stridulatory pulses at faster rates after exposure to prey larvae placed nearby the nest and after air-puff disturbances at the nest entrance than during unstimulated social interactions within the nest. Workers produce chirps (trains of stridulatory pulses) at faster rates after exposure to prey larvae than during unstimulated social interactions, including groups of chirps (bursts) where the intervals between chirps decrease below 60 ms. Such bursts do not occur in unstimulated social interactions. Chirp bursts with intervals <10 ms (disturbance bursts) occur immediately after air puffs at the nest entrance. Disturbance bursts are not observed after exposure to prey larvae or during unstimulated social interactions. The rates of disturbance bursts decline rapidly within 10 s after an air puff, whereas episodes of chirp bursts extend over periods of 30 s or longer when groups of ants are moving prey larvae into the nest. The differences in the rates of stridulatory pulses and chirps and in the durations of stridulatory activity observed in the context of different types, intensities, and durations of stimulation contribute to evidence that stridulation has a significant communicatory role in colony activities of many ant species, even in genera, such as Leptogenys, in which a stridulatory organ has not been retained in every species. "
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- kitteli. Lobopelta kitteli Mayr, 1870b: 966 (w.) INDIA. Wheeler, G.C. & Wheeler, J. 1976a: 52 (l.). Combination in Leptogenys: Emery, 1895k: 461. See also: Bingham, 1903: 60. Current subspecies: nominal plus altisquamis, laevis, minor, siemsseni, transiens.
- Bingham, C. T. 1903. The fauna of British India, including Ceylon and Burma. Hymenoptera, Vol. II. Ants and Cuckoo-wasps. London: Taylor and Francis, 506 pp. (page 60, see also)
- Chiu, Y. K., R. W. Mankin, and C. C. Lin. 2011. Context-Dependent Stridulatory Responses of Leptogenys kitteli (Hymenoptera: Formicidae) to Social, Prey, and Disturbance Stimuli. Annals of the Entomological Society of America. 104:1012-1020. doi:10.1603/AN11027
- Emery, C. 1895m. Viaggio di Leonardo Fea in Birmania e regioni vicine. LXIII. Formiche di Birmania del Tenasserim e dei Monti Carin raccolte da L. Fea. Parte II. Ann. Mus. Civ. Stor. Nat. 34[=(2(14): 450-483 (page 461, Combination in Leptogenys)
- Mayr, G. 1870b. Neue Formiciden. Verh. K-K. Zool.-Bot. Ges. Wien 20: 939-996 (page 966, worker described)
- Wheeler, G. C.; Wheeler, J. 1976a. Supplementary studies on ant larvae: Ponerinae. Trans. Am. Entomol. Soc. 102: 41-64 (page 52, larva described)
- Xu, Z. 1996b. A taxonomic study of the ant genus Leptogenys (Hymenoptera: Formicidae) in China. J. Yunnan Agric. Univ. 11: 222-227 (page 224, ee also) | <urn:uuid:48a1861b-4687-41f5-bbca-8975d8d8b8d1> | 2.65625 | 947 | Knowledge Article | Science & Tech. | 52.836184 | 95,489,427 |
Position: Senior Lecturer, Earth Sciences, Faculty of Science and Engineering, University of Waikato. Field: Earth and ocean sciences. Dr Willem de Lange, an earth scientist and lecturer at the ...READ MORE
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Join LEARNZ for their annual trek to Antarctica. At the end of 2018 go to a place that has fascinated explorers and scientists for over 100 years; Antarctica. Unlike early adventurers you won't ...
Fresh water is essential to life. On this trip you will see how quality freshwater drives a significant part of the local economy around Lake Taupō. Go whitewater rafting and fly-fishing with us ...
This survey will open in a new tab and you can fill it out after your visit to the site. | <urn:uuid:aff21ac3-4e60-4736-bc9a-d7c3f302cf7d> | 3.03125 | 266 | Content Listing | Science & Tech. | 56.005917 | 95,489,436 |
In a study of wild primates, reported this week (Nov. 7, 2011) in the Proceedings of the National Academy of Sciences, University of Wisconsin-Madison anthropologist Karen B. Strier describes a monkey society where equality and tolerance rule and where sexually mature males, still living at home, seem to get helpful access to mates by the mere presence of their mothers and other maternal kin.
The new study, which combines Strier’s long-term behavioral studies of wild muriquis with new genetic assays obtained from their scat, is important because it can inform conservation practices for critically endangered primates. But the study's big surprise, says Strier, was evidence that could extend the 'grandmother hypothesis,' the notion that human females evolved to live well past their reproductive years because of the rearing advantages conferred by post-menopausal women on their grandchildren.
The northern muriqui is a large, long-lived, socially complex and critically endangered New World primate. There are at most 1,000 animals left in patches of the Brazilian Atlantic Forest , the only place the species is found.
The monkey has been the subject of intensive behavioral study by Strier and her Brazilian colleagues for nearly three decades. Muriqui culture stands in stark contrast to many other primate societies: It is egalitarian, peaceful, and reproductive success, it seems, is spread evenly across the males of a group instead of determined by male social rank, as it is in most other species.
“The new data show who’s pulling the strings in muriqui society,” says Strier. “It’s the mothers.”
Genetic data from 67 monkeys – infants, mothers and possible sires – was gathered from monkey feces and analyzed with collaborators Sérgio Mendes and Valéria Fagundes of the Universidade Federal do Espirito Santo, Brazil, Anthony Di Fiore of the University of Texas at Austin, and Brazilian graduate student, Paulo Chaves at New York University. The genetic results, says Strier, neatly validate decades of behavioral studies, and provide a new window into muriqui society as Strier and her group could see, for the first time, paternal relatives across generations in highly stable social groups.
“We knew from long-term behavioral studies that mothers, who can live into their thirties, stay with their sons for a lifetime,” explains the Wisconsin anthropologist, “but the unexpected part of the story is that there may be reproductive advantages as a result of this living arrangement”.
“It would be really interesting now to look at paternity in other muriqui populations and in other species where mothers and sons stay together for life, to see if there are similar maternal effects,” says Strier.
The new research may also help explain why muriqui monkey females are so long lived.
The genetic data used in the study reveal that paternity in the group is more evenly spread across potential fathers, with 22 infants sired by 13 different males. The most successful male fathered just 18 percent of infants, a far lower percentage than reported for other primate species living in multi-male groups.
According to Strier, it can be difficult to tell from behavioral observations who’s a father and who isn’t, as muriqui males often line up patiently to mate with ovulating females.
“What we see is that no one male is monopolizing reproduction,” explains Strier. “The pattern is that a lot of different males are siring infants, confirming what we had predicted from their behavior.”
Strier’s studies have shown that in muriqui society, males stay in the groups they were born in while most females migrate to other groups at 6 or 7 years of age.
Intriguingly, no infants were the result of mating between males and a close maternal relative. “The finding that no inbreeding is occurring is important,” Strier avers. “Mating may be less random than we think because of the influence of mothers and other maternal kin. There must be some mechanism of recognition or avoidance.”
This is a crucial discovery, given that the 300 or so muriquis in Strier’s study population (representing nearly one-third of the entire species) are found in a protected reserve, where they are isolated from other muriquis.
The new PNAS report and supporting data open a vital new perspective on primate social dynamics. “Are we seeing mega moms? Or is this really just about being with your mom?"
The new study, says Strier, will also help with muriqui conservation, as what little muriqui habitat remains is fragmented. The data suggest that this muriqui population may be large enough for its members to avoid close inbreeding, so protection aimed at preserving and expanding habitat for existing groups would suffice.
At the same time, the influence of mothers and other maternal kin on male reproduction suggest the importance of extended families in this species. If animals living in smaller populations ever need to be relocated for conservation purposes, they should be moved with great care, Strier notes.
Karen Strier (608) 262-0302, firstname.lastname@example.org
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Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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Whale Species in South Australian Waters
It’s not just Southern Right whales that grace our waters in South Australia … 29 other whale species have been recorded, from small Common Dolphins (2m) to the largest animal ever to have lived, the Blue Whale (30m).
There are over 80 species of whales in the world, and all whales belong to the order Cetacea (Suh-TAY-sha). Baleen whales (like Southern Right whales) are filter feeders, using baleen to sieve tiny marine crustaceans from the sea, and have 2 blowholes on top of their head. They are primarily migratory species, needing to travel to the Antarctic waters in summer when their prey is most plentiful.
Toothed whales have teeth! Their main food is fish, although some species have other preferences as well, such as Killer whales (Orcas) which love seals and sea lions and Sperm Whales which prey on large squid. Toothed whales have only 1 blowhole.
Identifying Whale Species
Southern Right Whale
14 – 18 metres. Dark brown to black with white patches on belly; no dorsal fin; white skin callosities on head; V-shaped blow. A large, rotund whale. Endangered.
13 – 16 metres. Dark brown to black with white on flippers, flanks and belly; knobs on top of head and throat grooves; bushy blow; extremely long pectoral (side) fins. Vulnerable.
25-30 metres. Blue-grey mottled with light grey spots. The Blue whale is the largest animal to have ever lived on earth, even bigger than any dinosaur, and they can live up to 80 years or more, weighing between 100 – 200 tonnes.
12 – 18 metres. Black to brownish grey with white patches on mouth and belly; huge square head; heavily wrinkled skin; blow angles forward and to the left. Deep divers (up to 3km); feed on squid and fish. Classified as Insufficiently Known.
Orca (Killer Whale)
8 – 9 metres. Bold black and white patterns; tall, erect, triangular dorsal fin in males, more curved in females. Formidable predators eating fish, seals and even whales. Often hunt in pods. Classified as Insufficiently Known, but generally common and widespread.
Common Whale Behaviours
Whales exhale air from the blowholes on top of their heads at great pressure, causing moisture in their breath to condense and create a cloud or “blow”. Southern Rights have a distinctive V-shaped bushy blow and usually blow every minute or so after being submerged.
The eyes are set low down in Southern Right Whales because their natural predators and hazards come from below. However, they can lift their head and eyes above the surface when they want to have a look around. This is called spy hopping.
When whales wish to dive deeply or quickly, they will drop their heads and lift their tails out of the water, then swim straight down.
Whales most spectacular activity is when they launch themselves up out of the water then twist and fall back down. This is called breaching, and it is believed they do this for several reasons … to communicate, dislodge parasites, get a higher view, drive off predators or just play. Southern Rights usually only breach about three quarters of their bodies out of the water, but others such as Humpbacks can actually jump clear.
Tail flukes measure up to 5m across and weigh several tonnes. Whales will often lift them out of the water then back down hard with a loud crack and lots of spray. This is called tail lobbing, and is done for several reasons … to communicate, cool down, drive off predators or just for fun.
A less strenuous way for whales to communicate, is where they lay on their side at the surface and slap the water with their pectoral fin.
Whales frequently lay upside down, rolling on the surface with their pectoral fins stuck out for balance. There are various reasons for this … to simply rest or stretch; or, if a female, to avoid the demands of a hungry calf, or the advances of males during courtship.
Whales are able to suspend their tails above the water for quite long periods by dropping their heads and maintaining position with their pectoral fins. There are several reasons for this … to just rest, study the area around and below it or catch the wind and actually sail along. Also, if a female, to avoid the demands of a hungry calf, or the advances of males during courtship.
The 6 most commonly seen whales in South Australia are the Southern Right, Humpback, Sperm, Blue and Killer Whales, and Common Dolphins. Each species can be identified by the shape of their blow, and the size and shape of their tail flukes and pectoral fins, and overall body size, colour and shape.
Download: How to Identify 6 commonly seen Whales in SA (351 KB pdf )
Most of the other whales recorded in South Australia are seen less often than the 6 mentioned above and include the following species:
A group of dedicated and passionate Whale Spotters in Victor Harbor, together with staff from the South Australian Museum and South Australian Whale Centre take and catalogue photographs of Southern Right Whales in order to identify individuals and track Southern Right Whale movements and migration patterns.
Whale Research Organisations in Australia
- Australian Whale Conservation Society (AWCS)
- Dolphin Watch, Kangaroo Island & Victor Harbor
- Cetacean Ecology, Behaviour and Evolution Lab (CEBEL)
- CSIRO Marine & Shark Research
- Sydney Institute of Marine Sciences (SIMS)
- Australian Antarctic Division (AAD) Australian Marine Mammal Centre
- Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC)
- Macquarie University, NSW – Marine Mammal Research Group | <urn:uuid:bc5ea059-0f71-4d3a-a4ab-7d1c98d37b56> | 3.6875 | 1,232 | Knowledge Article | Science & Tech. | 51.73229 | 95,489,475 |
Authors: George Rajna
Researchers and students in the Graphene Flagship are preparing for two exciting experiments in collaboration with the European Space Agency (ESA) to test the viability of graphene for space applications. For the first time, scientists created a tunable artificial atom in graphene. They demonstrated that a vacancy in graphene can be charged in a controllable way such that electrons can be localized to mimic the electron orbitals of an artificial atom. Importantly, the trapping mechanism is reversible (turned on and off) and the energy levels can be tuned. Bumpy surfaces with graphene between would help dissipate heat in next-generation microelectronic devices, according to Rice University scientists. Scientists at The University of Manchester and Karlsruhe Institute of Technology have demonstrated a method to chemically modify small regions of graphene with high precision, leading to extreme miniaturisation of chemical and biological sensors. A new method for producing conductive cotton fabrics using graphene-based inks opens up new possibilities for flexible and wearable electronics, without the use of expensive and toxic processing steps. A device made of bilayer graphene, an atomically thin hexagonal arrangement of carbon atoms, provides experimental proof of the ability to control the momentum of electrons and offers a path to electronics that could require less energy and give off less heat than standard silicon-based transistors. It is one step forward in a new field of physics called valleytronics. In our computer chips, information is transported in form of electrical charge. Electrons or other charge carriers have to be moved from one place to another. For years scientists have been working on elements that take advantage of the electrons angular momentum (their spin) rather than their electrical charge. This new approach, called "spintronics" has major advantages compared to common electronics. It can operate with much less energy. Scientists have achieved the ultimate speed limit of the control of spins in a solid state magnetic material. The rise of the digital information era posed a daunting challenge to develop ever faster and smaller devices for data storage and processing. An approach which relies on the magnetic moment of electrons (i.e. the spin) rather than the charge, has recently turned into major research fields, called spintronics and magnonics.
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Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its radius and its electronic properties. Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, metallic character, ionic radius and reactivity. Periodic trends arise from the arrangement of elements in the periodic table and allow chemists to quickly and reliably predict an element's properties. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements. There are exceptions to these trends, such as that of ionization energy in Groups 3 and 6.
These periodic trends are based on the Periodic Law which states that if the chemical elements are listed in order of increasing atomic number, many of their properties go through cyclical changes, with elements of similar properties recurring at intervals. For example, after arranging elements in their increasing atomic numbers, many of the physical and chemical properties of Lithium are recurred into Sodium such as its vigorous reactivity with water, which again recurs in the next cycle starting with Potassium.
This principle was discovered after number of investigations done by scientists in nineteenth-century such as Lothar Meyer and Dmitri Mendeleev. Initially, no theoretical explanation for the Periodic Law was available and it was used only as an empirical principle. But, with the development of the electronic theory of atomic structure, it became possible to understand the theoretical basis for the Periodic Law. The periodic recurrence of elements with similar physical and chemical properties, when the elements are listed in order of increasing atomic number, results directly from the periodic recurrence of similar electronic configurations in the outer shells of respective atoms.
Discovery of Periodic Law constitutes one of the most singularly important events in the history of chemical science. Almost every chemist makes extensive and continued use of Periodic Law. Periodic Law also led to the development of the periodic table, which is widely used nowadays.
The atomic radius is the distance from the atomic nucleus to the outermost stable electron orbital in an atom that is at equilibrium. The atomic radius tend to decrease across a period from left to right. The atomic radius usually increases while going down a group due to the addition of a new energy level (shell). However, atomic radii tend to increase diagonally, since the number of electrons has a larger effect than the sizeable nucleus. For example, lithium (145 picometer) has a smaller atomic radius than magnesium (150 picometer).
The atomic radius can be further specified as:
- Covalent radius: half the distance between two atoms of a diatomic compound, singly bonded.
- Van der Waals radius: half the distance between the nuclei of atoms of different molecules in a lattice of covalent molecules.
- Metallic radius: half the distance between two adjacent nuclei of atoms in a metallic lattice.
- Ionic radius: half the distance between two nuclei
The ionization potential is the minimum amount of energy required to remove one electron from each atom in a mole of atoms in the gaseous state. The first ionization energy is the energy required to remove the first electron, and generally the nth ionization energy is the energy required to remove the atom's nth electron, after the (n−1) electrons before it has been removed. Trend-wise, ionization energy tends to increase while one progresses across a period because the greater number of protons (higher nuclear charge) attract the orbiting electrons more strongly, thereby increasing the energy required to remove one of the electrons. Ionization energy and ionization potentials are completely different. The potential is an intensive property and it is measured by "volt"; whereas the energy is an extensive property expressed by "eV" or "kJ/mole".
As one progresses down a group on the periodic table, the ionization energy will likely decrease since the valence electrons are farther away from the nucleus and experience a weaker attraction to the nucleus's positive charge. There will be an increase of ionization energy from left to right of a given period and a decrease from top to bottom. As a rule, it requires far less energy to remove an outer-shell electron than an inner-shell electron. As a result, the ionization energies for a given element will increase steadily within a given shell, and when starting on the next shell down will show a drastic jump in ionization energy. Simply put, the lower the principal quantum number, the higher the ionization energy for the electrons within that shell. The exceptions are the elements in the boron and oxygen family, which require slightly less energy than the general trend.
The electron affinity of an atom can be described either as the energy released by an atom when an electron is added to it, conversely as the energy required to detach an electron from a singly charged anion. The sign of the electron affinity can be quite confusing, as atoms that become more stable with the addition of an electron (and so are considered to have a higher electron affinity) show a decrease in potential energy; i.e. the energy gained by the atom appears to be negative. For atoms that become less stable upon gaining an electron, potential energy increases, which implies that the atom gains energy. In such a case, the atom's electron affinity value is positive. Consequently, atoms with a more negative electron affinity value are considered to have a higher electron affinity (they are more receptive to gaining electrons), and vice versa. However, in the reverse scenario where electron affinity is defined as the energy required to detach an electron from an anion, the energy value obtained will be of the same magnitude but have the opposite sign. This is because those atoms with a high electron affinity are less inclined to give up an electron, and so take more energy to remove the electron from the atom. In this case, the atom with the more positive energy value has the higher electron affinity. As one progresses from left to right across a period, the electron affinity will increase.
Although it may seem that Fluorine should have the greatest electron affinity, the small size of fluorine generates enough repulsion that Chlorine has the greatest electron affinity.
Electronegativity is a measure of the ability of an atom or molecule to attract pairs of electrons in the context of a chemical bond. The type of bond formed is largely determined by the difference in electronegativity between the atoms involved, using the Pauling scale. Trend-wise, as one moves from left to right across a period in the periodic table, the electronegativity increases due to the stronger attraction that the atoms obtain as the nuclear charge increases. Moving down in a group, the electronegativity decreases due to the longer distance between the nucleus and the valence electron shell, thereby decreasing the attraction, making the atom have less of an attraction for electrons or protons.
Valence electrons are the electrons in the outermost electron shell of an isolated atom of an element. Sometimes, it is also regarded as the basis of Modern Periodic Table. In a period, the number of valence electrons increases (mostly for light metal/elements) as we move from left to right side. However, in a group this periodic trend is constant, that is the number of valence electrons remains the same.
Valency in the periodic table across a period first increases and then decreases. There is no change going down a group.
The greater the number of core electrons, the greater the shielding of electrons from the core charge of the nucleus. For this reason ionization energy is lower for elements lower down in a group, and polarizability of species is higher for elements lower down in a group. The valency does not change going down a group since the bonding behavior is not affected by the core electrons. However, non-bonding interactions such as those just cited are affected by core electrons.
Metallic and non-metallic properties
Metallic properties increase down groups as decreasing attraction between the nuclei and the outermost electrons causes the outermost electrons to be loosely bound and thus able to conduct heat and electricity. Across the period, from left to right, increasing attraction between the nuclei and the outermost electrons causes metallic character to decrease.
Non-metallic property increases across a period and decreases down the group due to the same reason due to increase in nuclear attractive force. Metals are ductile while nonmetals are not.
- Harry H. Sister (1963). Electronic structure, properties, and the periodic law. New York: Reinhold publishing corporation.
The physical and chemical properties of elements are periodic functions of the charges on their atomic nuclei i.e. their atomic numbers.
- SparkNotes Editors (27 November 2015). "SparkNote on Atomic Structure". SparkNotes.com. Retrieved 29 November 2015. | <urn:uuid:09b7d89e-8cb2-4a79-a90a-9dc468edf5d7> | 3.828125 | 1,863 | Knowledge Article | Science & Tech. | 26.745722 | 95,489,493 |
The discovery, published in the Proceedings of the National Academy of Sciences, is part of a project funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and Medical Research Council (MRC) and may shed light on the possibilities of alleviating ageing and age-related characteristics in human cells.
Planarian worms have amazed scientists with their apparently limitless ability to regenerate. Researchers have been studying their ability to replace aged or damaged tissues and cells in a bid to understand the mechanisms underlying their longevity.
Dr Aziz Aboobaker from the University's School of Biology, said: "We've been studying two types of planarian worms; those that reproduce sexually, like us, and those that reproduce asexually, simply dividing in two. Both appear to regenerate indefinitely by growing new muscles, skin, guts and even entire brains over and over again.
"Usually when stem cells divide — to heal wounds, or during reproduction or for growth — they start to show signs of ageing. This means that the stem cells are no longer able to divide and so become less able to replace exhausted specialised cells in the tissues of our bodies. Our ageing skin is perhaps the most visible example of this effect. Planarian worms and their stem cells are somehow able to avoid the ageing process and to keep their cells dividing."
One of the events associated with ageing cells is related to telomere length. In order to grow and function normally, cells in our bodies must keep dividing to replace cells that are worn out or damaged. During this division process, copies of the genetic material must pass on to the next generation of cells. The genetic information inside cells is arranged in twisted strands of DNA called chromosomes. At the end of these strands is a protective 'cap' called a telomere. Telomeres have been likened to the protective end of a shoelace which stops strands from fraying or sticking to other strands.
Each time a cell divides the protective telomere 'cap' gets shorter. When they get too short, the cell loses its ability to renew and divide. In an immortal animal we would therefore expect cells to be able to maintain telomere length indefinitely so that they can continue to replicate. Dr Aboobaker predicted that planarian worms actively maintain the ends of their chromosomes in adult stem cells, leading to theoretical immortality.
Dr Thomas Tan made some exciting discoveries for this paper as part of his PhD. He performed a series of challenging experiments to explain the worm's immortality. In collaboration with the rest of the team, he also went some way to understanding the clever molecular trick that enabled cells to go on dividing indefinitely without suffering from shortened chromosome ends.
Previous work, leading to the award of the 2009 Nobel Prize for Physiology or Medicine, had shown that telomeres could be maintained by the activity of an enzyme called telomerase. In most sexually reproducing organisms the enzyme is most active only during early development. So as we age, telomeres start to reduce in length.
This project identified a possible planarian version of the gene coding for this enzyme and turned down its activity. This resulted in reduced telomere length and proved it was the right gene. They were then able to confidently measure its activity and resulting telomere length and found that asexual worms dramatically increase the activity of this gene when they regenerate, allowing stem cells to maintain their telomeres as they divide to replace missing tissues.
Dr Tan pointed out the importance of the interdisciplinary expertise: "It was serendipitous to be sandwiched between Professor Edward Louis's yeast genetics lab and the Children's Brain Tumour Research Centre, both University of Nottingham research centres with expertise in telomere biology. Aziz and Ed kept demanding clearer proof and I feel we have been able to give a very satisfying answer."
However, what puzzled the team is that sexually reproducing planarian worms do not appear to maintain telomere length in the same way. The difference they observed between asexual and sexual animals was surprising, given that they both appear to have an indefinite regenerative capacity. The team believe that sexually reproductive worms will eventually show effects of telomere shortening, or that they are able to use another mechanism to maintain telomeres that would not involve the telomerase enzyme.
Dr Aboobaker concluded: "Asexual planarian worms demonstrate the potential to maintain telomere length during regeneration. Our data satisfy one of the predictions about what it would take for an animal to be potentially immortal and that it is possible for this scenario to evolve. The next goals for us are to understand the mechanisms in more detail and to understand more about how you evolve an immortal animal."
Professor Douglas Kell, BBSRC Chief Executive, said: "This exciting research contributes significantly to our fundamental understanding of some of the processes involved in ageing, and builds strong foundations for improving health and potentially longevity in other organisms, including humans."
Emma Thorne | EurekAlert!
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
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GLOBAL WARMING An Interesting but Insignificant Problem Is Global Warming Real? Models say YES; data say NO A CRITIQUE (2005) OF IPCC CLAIMS Presentation by S. Fred Singer Professor of Environmental Sciences Emeritus University of Virginia
An Interesting but Insignificant Problem
Is Global Warming Real? Models say YES; data say NO
A CRITIQUE (2005) OF IPCC CLAIMS
Presentation by S. Fred Singer
Professor of Environmental Sciences Emeritus
University of Virginia
Science & Environmental Policy Project, Arlington, VA 22202
**Atmospheric levels of carbon dioxide, methane, and other greenhouse (GH) gases are rising.
**Climate models project an increase in global temperatures of 1.5 to 4.5 C (by about 2100 when CO2 levels may be twice the pre-industrial value).
**But actual observations do not support the theoretical models and allow for only about 0.6 C over present temperatures.
**The consequences of such a small change are not likely to be significant.
The existing concern about Global Warming (GW) is based mainly on the reports of the UN-sponsored Intergovernmental Panel on Climate Change (IPCC). In particular, its Third Assessment Report (TAR) of 2001 includes economic growth scenarios that could give a temperature rise of up to 5.8 C.
Its Summary for Policymakers (SPM) claims that “there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.”
WE DON’T SEE SUCH EVIDENCE
The IPCC (2001) conclusion about human-caused GW is based on three pieces of “evidence.” None of these stand up to scrutiny.
1) Temperature data from different “proxy” sources (tree rings, etc) show the 20th century to be the warmest in the last 1000 years. (Hockey stick graph)
2) Global average surface temperatures have increased by 0.6 C over the 20th century, with about half the increase since 1976, making the past decade the warmest.
3) Climate models account for the temperature history of the 20th century – provided they include both natural forcing factors affecting climate (solar variability, volcanoes) and forcings from human activities (GreenHouse gases, aerosols).
Proxy data (from tree rings, ice cores, lake and ocean sediments, corals, etc) indeed give information about the past. But they do not support the IPCC claim.
Independent researchers, incl also GW promoters, agree that the hockeystick is broken, but now argue, rather disingenuously, that the hockeystick never really proved the existence of anthropogenic global warming (AGW) -- but at best provided only circumstantial evidence. [von Storch, Cubasch, Rahmstorf].
In addition, as hundreds of studies have shown, there was no stable "pre-industrial climate" and temperatures often exceeded present levels.
Few scientists dispute that the global average temperature rose during the early part of the 20th century -- up to about 1940.
The main dispute centers on whether there has been a warming since 1979, the year that weather satellites first began pole-to pole measurements of atmospheric temperatures.
There have been several unsuccessful attempts to discredit the satellite results. It seems more likely, however, that the surface data are contaminated (for example, by urban heat islands) and produce a spurious global warming trend.
In addition, methods for deriving sea-surface temperatures are questionable.
One thing is certain: One cannot assert that the atmosphere is currently warming appreciably – nor that the cause is anthropogenic.
California weather stations show
warming trend in counties with >1 million people
no warming trend in counties with <100,000
[Ref: Goodridge, Bull Am Met Soc, July 1996]
[Note temperature increases to a max in 1940,
followed by cooling trend to ~1975]
The remaining IPCC claim is that climate models can explain the global mean temperature record of the 20th century with a combination of natural forcings (from solar variability and volcanoes) and anthropogenic forcings (GH gases, aerosols).
But this claimed agreement seems to be nothing more than a case of curve fittingwith the choice of a number of arbitrary parameters [Ref: G. North]. For example, a computer-modeling exercise demonstrated that climate sensitivity can vary between 1.9 and 11.5 C (for a doubling of atmospheric CO2 concentration) by just changing slightly any of a half-dozen parameters dealing with clouds [Stainforth 2005]. Similarly, aerosols show a wide range of optical parameters and therefore forcings.
The crucial test would be to demonstrate agreement between model results and observed temperature trends – not for just the global mean but as a function of latitude – or even just for the NH and SH separately.
We have tried to demonstrate here that the IPCC claim for existence of “new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities” cannot be maintained.
** Satellites (MSU-UAH) show a trend of 0.08 C per decade. [It would be less if one allows for the 1998 El Nino peak.]
** Assume (conservatively) that ALL is due to increasing CO2.
** Then the surface trend should be about 20% less (acc. to GH theory) --or about 0.065 C/decade.
** Assume (again conservatively) that CO2 will increase exponentially, then the temp trend will be linear (acc to radiation theory).
** So by 2100 we should see an increase of at most 0.6 C over the present value.
[If CO2 increases at 0.04%/yr, then the value in 2100 will be 555ppm; at 0.03%/yr it will be 505ppm vs pre-industrial 280ppm and present 380ppm.]
As a consequence of greenhouse forcing, all GCMs (general circulation models) predict a positive temperature trend that is greater for the troposphere than the surface -- increasing with altitude until it reaches a maximum ratio with respect to the surface of as much as 1.5 to 2.0 at about 8 km. However, the temperature trends from several independent observational data sets show decreasing trends with altitude, as well as mostly negative trend values. This disparity indicates that climate models fail to account for the effects of greenhouse forcings [Douglass, Pearson, Singer 2004]
**Insufficient resolution, due to limited computing power
**Inadequate parameterization of clouds and cloud physics
[Climate sensitivity can vary from 1.9 to 11.5 C (Stainforth 2005)]
**Inadequate knowledge of magnitude and sign of Water Vapor feedback, (determined mainly by unknown WV levels in upper troposphere)
**Inadequate knowledge of natural and human forcings
**It calls for industrialized nations to cut 5% from 1990 emission levels by 2012
**This would reduce the model- calculated warming by only 0.05 C (one-twentieth of a degree)
**Without US participation, this becomes an undetectable 0.02 C (too small to measure)
**With emission trading in force, there would be no reduction
**Stabilization of GH gas levels requires a reduction of 60 to 80% by ALL nations! It would not stabilize climate.
**Poll of leaders of Am Meteorological Society 1991
**International Heidelberg Appeal 1992
**Statement of Atmospheric Scientists 1992
**Leipzig Declaration of climate specialists 1996 and 2005
**Oregon Petition against Kyoto (by nearly 20,000 scientists)
**Statement of Am Assoc of State Climatologists 2001
**Report by the Russian Academy of Sciences May 2004
**Poll of 500 international climate specialists (D. Bray 2004)
**An international survey (2004) among some 500 climatologists found that "a quarter of respondents still question whether human activity is responsible for the most recent climatic changes." (Der Spiegel, 24 January 2005; http://service.spiegel.de/cache/international/spiegel/0,1518,342376,00.html).
**After the Russian Academy of Sciences issued its report in May 2004, President Vladimir Putin has termed Kyoto “scientifically flawed.”
**Even Tony Blair has emphasized the ongoing scientific debates among climate scientists: "So it would be true to say the evidence [on anthropogenic global warming] is still disputed” (Davos Speech, 26 January 2005; http://www.number-10.gov.uk/output/Page7006.asp).
**“Global warming is a greater threat than WMD” (Hans Blix)
**“Global warming is a greater threat than terrorism”
**“Antarctica is likely to be the world's only habitable continent by the end of this century if global warming remains unchecked." (Sir David King, UK Chief Scientist).
**“The science is settled” (Tim Wirth, Al Gore, etc. in 1996))
(Decadal time-scale) Climate changes are mainly controlled by Sun, not by CO2:
See correlation in Stalagmite data [Neff et al. Nature 2001]: Carbon-14 shows solar changes, oxygen-18 climate changes
o Global changes are mainly natural; human effects likely minor in comparison.
o Worldwide poverty should be top priority environmental target; encompasses fresh water, disease control, and other human needs.
o Supply of low cost energy is essential for economic growth to overcome poverty.
o Resources spent to reduce GH gases are a wasted investment, raise energy costs, and result in perpetuating poverty. | <urn:uuid:79f5291d-1fc6-437b-8ec2-6f5f12134c3d> | 3.1875 | 2,047 | Nonfiction Writing | Science & Tech. | 44.24875 | 95,489,528 |
Free energy. It is possible?
“Free energy” refers to the idea of a system that can generate power by taking energy from a limitless source.
As far as we know :
The total amount of energy in a closed system is fixed, free energy IS NOT POSSIBLE. The total amount of energy in the universe cannot increase or decrease. Energy is conserved https://en.wikipedia.org/wiki/Conservation_of_energy. Free energy implies a system which generates more energy than the input energy. According to second law of thermodynamics, there is no machine whose efficiency is 100%. Entropy of a system increases while doing an irreversible process.
CONCLUSIONS : infinite amount of energy (FREE ENERGY ) is impossible. But, a large source of energy is possible.
LARGE SOURCE OF ENERGY | <urn:uuid:cc285055-9f2b-4932-8733-aefbb42eabe1> | 3.484375 | 175 | Knowledge Article | Science & Tech. | 33.966585 | 95,489,532 |
We just slipped past the year’s longest day and highest sun. Ever wonder why the summer solstice isn’t the warmest day of the year?
Because it takes time to overcome the chilling effects of winter.
Temperatures don’t peak at the solstice. If they did, May and the first half of June would have produced steadily increasing warmth. Instead, they generated a seesaw of warm and cool conditions.
Here in the Inland Northwest, you may recall donning sunscreen and a T-shirt one day and zipping up your fleece jacket the next. Meteorologists call this kind of fluctuating weather “highly variable,” and boy, did we experience a lot of it during the past month and a half.
The high barely hit 50 degrees on May 1, followed by a summerlike leap to 83 degrees on May 4 and then a springlike drop to 53 on May 6.
On May 30, the temperature rose to 90 degrees, only to drop to 72 the next day. The steepest day-to-day variance occurred when the mercury hit 94 degrees on June 7 and plunged by 20 degrees to 74 on June 8.
Although the northern hemisphere absorbs more and more sunlight in the weeks preceding the solstice, it takes time for the land and surrounding oceans to retain the heat. Until then, it’s not unusual for daily temperatures to jump between cool and warm. Compare this to what happens after a glass of warm water is added to a shallow bowl of cold water. The warm and cold waters slosh back and forth before the overall temperature increases and levels out.
Speaking of leveling out, the region will continue to warm up, with the hottest days arriving in July and August. Temperatures are expected to run slightly warmer than normal across the Pacific Northwest.
Nic Loyd is a meteorologist with Washington State University’s AgWeatherNet. Linda Weiford is a WSU news writer and weather geek. Contact: email@example.com or firstname.lastname@example.org. | <urn:uuid:98cd8897-da75-456e-8eb5-0c3297f7e018> | 3.390625 | 433 | News Article | Science & Tech. | 63.257274 | 95,489,537 |
Mammalian Y chromosomes are often neglected from genomic analysis. Due to their inherent assembly difficulties, high repeat content, and large ampliconic regions, only a handful of species have their Y chromosome properly characterized.
Teak (Tectona grandis L. f.) is one of the precious bench mark tropical hardwood having qualities of durability, strength and visual pleasantries. Natural teak populations harbour a variety of characteristics that determine their economic, ecological and environmental importance.
Background: Chloroplasts are organelles that conduct photosynthesis in plant and algal cells. Chloroplast genomes code for around 130 genes, and the information they contain is widely used in agriculture and studies of evolution and ecology.
Generating a complete, de novo genome assembly for prokaryotes is often considered a solved problem. However, we here show that Pseudomonas koreensis P19E3 harbors multiple, near identical repeat pairs up to 70 kilobase pairs in length.
The Drosophila genus is a unique group containing a wide range of species that occupy diverse ecosystems. In addition to the most widely studied species, Drosophila melanogaster, many other members in this genus also possess a well-developed set of genetic tools.
Oryza coarctata plants, collected from Sundarban delta of West Bengal, India, have been used in the present study to generate draft genome sequences, employing the hybrid genome assembly with Illumina reads and third generation Oxford Nanopore sequencing technology.
Eukaryotic genome assembly remains a challenge in part because of the prevalence of complex DNA repeats. This is a particularly acute problem for holocentric nematodes because of the large number of satellite DNA sequences found throughout their genomes.
The haploid Saccharomyces cerevisiae strain CEN.PK113-7D is a popular model system for metabolic engineering and systems biology research. Current genome assemblies are based on short-read sequencing data scaffolded based on homology to strain S288C.
The human genome reference sequence remains incomplete due to the challenge of assembling long tracts of near-identical tandem repeats, or satellite DNAs, that are highly enriched in centromeric regions.
Long-read sequencing technologies such as Pacific Biosciences and Oxford Nanopore MinION are capable of producing long sequencing reads with average fragment lengths of over 10,000 base-pairs and maximum lengths reaching 100,000 base- pairs.
Recent updates in sequencing technology have made it possible to obtain Gigabases of sequence data from one single flowcell. Prior to this update, the nanopore sequencing technology was mainly used to analyze and assemble microbial samples.
We have sequenced the genome of the endangered European eel using the MinION by Oxford Nanopore, and assembled these data using a novel algorithm specifically designed for large eukaryotic genomes. For this 860 Mbp genome, the entire computational process takes two days on a single CPU.
Nippostrongylus brasiliensis, a nematode parasite of rodents, has a parasitic life cycle that is an extremely useful model for the study of human hookworm infection, particularly in regards to the induced immune response.
Advances in 3rd generation sequencing have opened new possibilities for benchtop whole genome sequencing. The MinION is a portable device that uses nanopore technology and can sequence long DNA molecules.
The ability to quickly obtain accurate genome sequences of eukaryotic pathogens at low costs provides a tremendous opportunity to identify novel targets for therapeutics, develop pesticides with increased target specificity and breed for resistance in food crops.
Background: Oxford Nanopore Technologies Ltd (Oxford, UK) have recently commercialized MinION, a small single-molecule nanopore sequencer, that offers the possibility of sequencing long DNA fragments from small genomes in a matter of seconds.
Motivation: Single Molecule Real-Time (SMRT) sequencing technology and Oxford Nanopore technologies (ONT) produce reads over 10kbp in length, which have enabled high-quality genome assembly at an affordable cost.
The MinION is a portable single-molecule DNA sequencing instrument that was released by Oxford Nanopore Technologies in 2014, producing long sequencing reads by measuring changes in ionic flow when single-stranded DNA molecules translocate through the pores.
Human herpesvirus type 1 (HHV-1) has a large double-stranded DNA genome of approximately 152 kbp that is structurally complex and GC-rich. This makes the assembly of HHV-1 whole genomes from short-read sequencing data technically challenging. | <urn:uuid:f949d9e4-cf8c-464d-964d-1b65fab37dfc> | 3.21875 | 949 | Content Listing | Science & Tech. | 12.170009 | 95,489,552 |
The Genetic and Molecular Basis of Flower Development in Arabidopsis
My laboratory studies pattern development in flowers, concentrating on two basic patterns that develop in parallel. The first is the pattern of organ number and position. The flowers of the plant we study, the mustard Arabidopsis thaliana, have a total of 16 organs: four organs in the first organ whorl, with a 90-degree angle between adjacent organs, four organs inside and alternate to the first whorl organs, six third-whorl organs with their own characteristic spacing and divergence angles, and two fourth-whorl organs (Müller, 1961; Smyth et al., 1990). This number and position of floral organs is specific to members of the mustard family and close relatives; other families have quite different patterns of organ number and position. The second pattern, which develops to a large degree independently of the first, is the pattern of organ identity. From the outside to the inside of the flower, one finds the four organ types sepal, petal, stamen, then carpel occurring in this order in successive organ whorls. This radial order of organ identities is not at all family-specific, being almost completely uniform in flowering plants. We would like to understand how the activities of specific genes produce both patterns in developing floral primordia, to understand how these patterns have arisen in the evolution of flowering plants, and to know what differences in the genes that control these patterns give the diversity of flower forms that exists in nature.
KeywordsFlower Development Floral Organ Organ Identity Homeotic Gene Floral Meristem Identity
Unable to display preview. Download preview PDF.
- Bowman, J.L., Yanofsky, M.F., and Meyerowitz, E.M. (1988). Arabidopsis thaliana: A review. Oxford Surv. Plant Mol. Cell. Biol. 5, 57–87.Google Scholar
- Bowman, J.L. (1991) Molecular genetics of flower development in Arabidopsis thaliana. Ph.D. thesis, California Institute of Technology.Google Scholar
- Bowman, J.L., Alvarez, J., Weigel, D., Meyerowitz, E.M and Smyth, D.R. (1993) The specification of floral meristem identity in Arabidopsis thaliana. submitted for publication.Google Scholar
- Goto, K. and Meyerowitz, E.M. (1993) Molecular cloning, expression and biochemical activity of the Arabidopsis homeotic gene PISTILLATA. submitted for publication.Google Scholar
- Meyerowitz, E.M., Bowman, J.L., Brockman, L.L., Drews, G.N., Jack, T., Sieburth, L.E. and Weigel, D. (1991) A genetic and molecular model for flower development in Arabidopsis thaliana. Development 112, suppl. 1, 157–168.Google Scholar
- Okamuro, J., den Boer, B., Van Montagu, M. and Jofuku, D. (1993) APETALA2: Characterization of a novel plant homeotic regulatory gene from Arabidopsis. J. Cell. Biochem. suppl. 17B, 16.Google Scholar
- Weigel, D.W. and Meyerowitz, E.M. (1993) Activation of Arabidopsis floral homeotic genes. submitted for publication.Google Scholar | <urn:uuid:639b0447-0145-4244-a3f3-239a5c10890f> | 2.875 | 716 | Academic Writing | Science & Tech. | 50.887903 | 95,489,553 |
Nitrogen-containing organic compounds are important products as well as intermediates for many pharmaceuticals, agrochemicals, and chemicals used in electronics. Air contains plenty of nitrogen, but it is in a form that cannot be used for chemical syntheses: nitrogen gas, a molecule made of two nitrogen atoms, is highly inert. The main source of nitrogen today involves a detour by way of synthetic ammonia, a process requiring a lot of energy and explosive hydrogen gas under harsh conditions.
In order to find synthetic pathways that do not rely on ammonia, scientists are searching for ways to fix atmospheric nitrogen in the form of higher-value organic compounds. Chemists working with Paul J. Chirik at Cornell University (Ithaca, New York) have now found an interesting new method, which they describe in the journal Angewandte Chemie: they have bound nitrogen to carbon dioxide while maintaining the nitrogen–nitrogen bond, forming a hydrazine derivative. The metal hafnium promotes this reaction.
The two nitrogen atoms in a nitrogen molecule are so happy with each other that they have little incentive to enter into chemical bonds with other atoms. Direct formation of a bond between carbon and nitrogen, a requirement for the formation of organonitrogen compounds without resorting to ammonia, is a serious challenge for scientists. The nitrogen has to be “outsmarted”. While it does not easily enter into chemical bonds with organic substances, molecular nitrogen does have a tendency to form coordination complexes by binding to a metal. When the nitrogen acts as ligand in these complexes, it receives electrons from the metal atom disrupting the strong nitrogen-to-nitrogen triple bond. Chemists often refer to this process as “activating” the nitrogen ligand, as new chemistry is now possible.
Chirik and his co-workers found out that the nitrogen gets activated just right in a hafnocene complex (whose hafnium atoms each have two aromatic five-membered carbon rings as additional ligands), in which the nitrogen molecule is grabbed side-on by two hafnium atoms,. Carbon dioxide can then react with the activated nitrogen molecule. Two carbon dioxide molecules push their way in between the nitrogen and the hafnium. One of the two nitrogen atoms thus forms two strong new bonds to two carbon atoms from the carbon dioxide. One of the nitrogen–nitrogen bonds remains intact. By using an organosilicon compound, the cores of the hafnocene complexes can be released—in the form of a silicon-containing organic hydrazine derivative.
Author: Paul J. Chirik, Cornell University, Ithaca (USA), http://www.chem.cornell.edu/faculty/index.asp?fac=19
Title: Nitrogen–Carbon Bond Formation from N2 and CO2 Promoted by a Hafnocene Dinitrogen Complex Gives Access to a Substituted Hydrazine
Angewandte Chemie International Edition, doi: 10.1002/anie.200604099
| Angewandte Chemie
Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria
Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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16.07.2018 | Earth Sciences | <urn:uuid:b39b6aaf-bada-48e5-b845-1960425e744f> | 4.09375 | 1,276 | Content Listing | Science & Tech. | 36.627872 | 95,489,558 |
The Complex World of Polysaccharides
by Desiree Nedra Karunaratne (ed.)
Publisher: InTech 2012
Number of pages: 634
The complex world of polysaccharides is a compilation of the characteristics of a variety of polysaccharides from plants, animals and microorganisms. The diversity of these polysaccharides arises from the structural variations and the monosaccharide content which is under genetic control.
Home page url
Download or read it online for free here:
by J.D. Roberts, R. Stewart, M.C. Caserio - W. A. Benjamin, Inc.
Interesting and up-to-date picture of organic chemistry with the rigorous approach to the relevant topics, and an emphasis on spectroscopy. The simple introduction to the subject should make the book appealing to the general student.
- National Academies
This book explores the universe of polymers in various fields, such as medicine and biotechnology information and communication, housing and construction, energy and transportation, national defense, and environmental protection.
by Amgad M. Rabie, at al. - Wikibooks
Organic chemistry is primarily devoted to the unique properties of the carbon atom and its compounds. These compounds play a critical role in biology and ecology, Earth sciences and geology, physics, industry, medicine and - of course - chemistry.
by Author J. C. Jones - BookBoon
The book on the physical properties of hydrocarbons. It is of interest to students and professionals in chemical engineering, fuel technology and mechanical engineering. The author have used it in a newly set up chemical engineering degree course. | <urn:uuid:c811712b-a4cd-4533-aaa5-49c888ba679f> | 2.65625 | 345 | Content Listing | Science & Tech. | 30.031783 | 95,489,567 |
Neutrino Associated with Distant Blazar Jet
With equipment frozen deep into ice beneath Earth's South Pole, humanity appears to have discovered a neutrino from far across the universe. If confirmed, this would mark the first cleardetection of cosmologically-distant neutrinos and the dawn of anobserved association between energetic neutrinos and cosmic rays created by powerful jets emanating from blazing quasars (blazars). Once the Antarctican IceCube detector measured an energetic neutrino in 2017 September, many of humanity's premier observatories sprang into action to try to identify a counterpart in light. And they did. An erupting counterpart was pinpointed by high energy observatories including AGILE, Fermi,HAWC, H.E.S.S., INTEGRAL, NuSTAR, Swift, and VERITAS, which found that gamma-ray blazar TXS 0506+056 was in the right direction and with gamma-rays from a flare arriving nearly coincidental in time with the neutrino. Even though this and otherposition and time coincidences are statistically strong, astronomers will await other similar neutrino - blazar light associations to be absolutely sure. Pictured here is an artist's drawing of a particle jet emanating from a black hole at the center of a blazar.
For image credit and copyright guidance, please visit the image website https://apod.nasa.gov/apod/ap180716.html#mysteries_of_space #NASA #astrophysics #physics #spaceX #roscosmos #Mars #math #astronomy #knowledge #power #cosmos | <urn:uuid:5f67b0df-d18d-4bc0-92da-2eb779e7d202> | 3.59375 | 346 | News Article | Science & Tech. | 28.502998 | 95,489,588 |
Plants branched from base or nearly so, 10-45(-60) cm, sparsely covered with dendroid or almost stellate hairs, becoming glabrous. Leaf blades linear-lanceolate, linear, or occasionally narrowly linear, usually plane, 1.5-4 × (0.1-)0.2-0.4(-0.5) cm. Inflorescences usually compact and dense, rarely ± lax and interrupted in proximal 1/2, clavate, narrowly clavate, or almost ovate in outline. Bracts ovate or ovate-lanceolate (rarely narrowly ovate-lanceolate), ca. (0.5-)1-3 × 0.4-0.8 cm. Perianth segment 1. Fruits light brown, brown, dark brown, or deep olive green, often with reddish brown spots and whitish warts, convex abaxially, usually plane or slightly concave adaxially, obovate or obovate-elliptic, usually broadest beyond middle, (3.2-)3.5-4.5(-4.7) × (2-)2.4-3 mm; wing translucent only at margin (or in marginal 1/2), thick, 0.2-0.4(-0.5) mm wide, margins entire or indistinctly erose, apex broadly triangular, rarely rounded or very indistinctly emarginate. Flowering late summer-fall. Sand dunes, sandy and gravely shores, waste places; 0-100 m; Alta., Man., Ont., Que., Sask.; Ill., Ind., Mich., Minn., N.Y., N.Dak., Ohio, Wis.; introduced in Europe; Asia (se Siberia). Corispermumpallasii is placed in subsect. Pallasiana Mosyakin, which is evidently of Asian origin. Related taxa are widespread in southern Siberia, central Asia, Mongolia, and China. It is also widespread in Europe, where it was most probably initially introduced in Germany by German botanists and gardeners, who obtained seeds from Siberia through Russian botanical gardens (G. F. Schnittspahn 1851; U.-V. Köck 1986). In Europe this species was known as C. leptopterum (Ascherson) Iljin. It is not known yet whether this species was introduced to North America or is at least partly native within its North American range. Judging from the very close taxonomic affinity of C. pallasii to other, native North American taxa (e.g., C. americanum, C. villosum, C. ochotense, C. hookeri) and morphological similarity of its fruits to some fossil Corispermum fruits, the hypothesis of the native status of C. pallasii in North America seems to be preferable; secondary introduction of some populations from Europe is also not improbable.
Annual herb 10 cm - 0.6 m tall Stem: upright or ascending, branched from at or near base, sparsely covered with branched (dendroid) or nearly star-shaped (stellate) hairs, often becoming hairless with age. Leaves: alternate, stalkless, 1.5 - 4 cm long, 1 - 5 mm wide, linear to narrowly lance-shaped with a flat base and pointed tip, usually flat. Inflorescence: a terminal, dense spike of flowers, narrowly club-shaped (clavate) to almost egg-shaped. Flowers: solitary in axils of leaf-like bracts, greenish, tiny, scale-like, with one sepal and no petals. Bracts 0.5 - 3 cm long, 4 - 8 mm wide, egg-shaped to egg- lance-shaped. Stamen one, exserted. Stigmas two. Fruit: an achene, vertical, stalkless, brownish to dark olive green, often spotted reddish brown, 3.5 - 4.5 mm long, 2 - 3 mm wide, reverse egg-shaped, usually broadest past the middle, convex beneath, more or less flat above, whitish-warty, winged. Wing translucent at margin, to 0.5 mm wide, thick.
Similar species: No information at this time.
Flowering: July to September
Habitat and ecology: Introduced from Eurasia. Characteristically found on the sandy beaches of Lake Michigan.
Occurence in the Chicago region: non-native
Etymology: Corispermum comes from the Greek words coris, meaning bedbug, and sperma, meaning seed. Pallasii is named after Peter Simon Pallis, a German Botanist and Zoologist.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
On sand dunes; known from Lake, La Porte, and Porter Counties. | <urn:uuid:947ccf1a-5d43-49f9-974e-be96784f4624> | 3.0625 | 1,048 | Knowledge Article | Science & Tech. | 59.349665 | 95,489,589 |
Bacterial 'Computer' Solves Math Problem
Modified E. coli bacteria were successfully engineered to solve a difficult mathematical puzzle, according to research published today in the Journal of Biological Engineering.
(Scanning electron micrograph of E. coli bacteria)
The DNA of the bacteria was modified to create a special purpose 'computing device' to solve the Hamiltonian Path Problem, a surprisingly intractable brainteaser. A simple example would be plotting the shortest possible route that would take you to the ten largest cities in the US from New York City to San Jose, California.
This simple problem is surprisingly difficult to solve. There are over 3.5 million possible routes to choose from, and a regular computer must try them out one at a time to find the shortest. Alternatively, a computer made from millions of bacteria can look at every route simultaneously...
The researchers coded a simplified version of the problem, using just three cities, by modifying the DNA of Escherichia coli bacteria. The cities were represented by a combination of genes causing the bacteria to glow red or green, and the possible routes between the cities were explored by the random shuffling of DNA. Bacteria producing the correct answer glowed both colours, turning them yellow.
The experiment worked, and the scientists checked the yellow bacteria's answer by examining their DNA sequence.
Fans of sf writer Greg Bear recall his intellectual cells, specially engineered to solve problems.
His first E. coli mutations had had the learning capacity of planarian worms; he had run them through simple T-mazes, giving sugar rewards. They had soon outperformed planaria...
Via Bacteria make computers look like pocket calculators.
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European Space Agency
Dr. Claus Zehner is an employee of the European Space Agency and has been working on the exploitation of atmospheric satellite measurements since 1993. Since Nov. 2016 he is the Mission Manager of the Sentinel-5 Precursor satellite.
The Status of the Sentinel-5 Precursor Mission and First Results
The Sentinel-5 Precursor mission is the first atmospheric Copernicus mission and was successfully launched on 13th October 2017. The mission provides daily global information at unprecedented spatial resolution (~7x3.5km2) on trace gases and aerosols important for air quality, climate forcing and the ozone layer. The only payload of the mission is the TROPOMI instrument (co-funded by ESA and the Netherlands), which is a nadir push-broom spectrometer measuring in the ultraviolet, visible, near-infrared and the shortwave infrared. The selected wavelength range allows for the observation of key atmospheric constituents including O3, NO2, CO, SO2, CH4, CH2O, aerosols and clouds.
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Tübingen University geoscientists find traces of early oxygen-producing bacteria in 3 billion year old sediments in South Africa’s Pongola Basin
In the Earth’s early history, several billion years ago, only traces of oxygen existed in the atmosphere and the oceans. Today’s air-breathing organisms could not have existed under those conditions. The change was caused by photosynthesizing bacteria, which created oxygen as a by-product – in vast amounts. 2.5-billion-year-old rock layers on several continents have yielded indications that the first big increase in the proportion of oxygen in the atmosphere took place then.
Now, working with international colleagues, Dr. Benjamin Eickmann and Professor Ronny Schönberg, isotope geochemists from the University of Tübingen have discovered layers in South Africa’s Pongola Basin which bear witness to oxygen production by bacteria as early as 2.97 billion years ago. That makes the Basin the earliest known home to oxygen-producing organisms – known as an oxygen oasis. The study has been published in the latest Nature Geoscience.
Conditions on Earth some three billion years ago were inhospitible to say the least. The atmosphere contained only one-one hundred thousandth of the oxygen it has today. The primeval oceans contained hardly any sulfate; but they did contain large amounts of ferrous iron. When bacteria started producing oxygen, it could initially bond with other elements, but began to enrich the atmosphere in a massive oxygen emission event around 2.5 billion years ago.
“We can see that in the disappearance of reduced minerals in the sediments on the continents. Certain sulfur signatures which can only be formed in a low-oxygen atmosphere are no longer to be found,” says Benjamin Eickmann, the study’s lead author.
This event, which could be described as global environmental pollution, went down in the Earth’s history as the Great Oxygenation Event. It was a disaster for the early bacteria types which had evolved under low-oxygen conditions; the oxygen poisoned them. “However, after the first big rise, the atmosphere only contained 0.2 percent oxygen; today it’s around 21 percent,” Eickmann explains.
Exposed to an atmosphere which contained increasing amounts of oxygen, the continents were subject to enhanced erosion. That led to more trace elements entering the oceans. The improved supply of nutrients in turn led to more life forms in the seas.
Sulfur signatures as an archive of Earth history
In their current study the researchers investigated the 2.97-bilion-year-old sediments deposited in the Pongola Basin in what is now South Africa. From the proportions of sulfur isotopes (particularly the of 34S/32S ratio), in the sediments, the researchers are able to conclude that the bacteria used the sulfate in the primeval seas as a source of energy, reducing it chemically.
“Sulfate is a form of oxidized sulfur. A higher concentration of sulfate in the water indicates that sufficient free oxygen must have been present in the shallow sea of the Pongola Basin,” Ronny Schönberg says. This free oxygen must have been produced by other, photosynthesizing bacteria. At the same time, another sulfur isotope signature (the 33S/32S ratio) in these sediments indicates a continued reduced, very low-oxygen atmosphere.
“That makes the Pongola Basin the oldest oxygen oasis known to date. The oxygen was building up in the water long before the Great Oxygenation Event, Schönberg explains. Several hundred million years later, the steadily rising levels of oxygen led to the oxidation of the atmosphere, and that is what made life on Earth – in all its variety as we know it today – even possible.
Benjamin Eickmann, Axel Hofmann, Martin Wille, Thi Hao Bui, Boswell A. Wing and Ronny Schoenberg: Isotopic evidence for oxygenated Mesoarchaean shallow oceans. Nature Geoscience, DOI 10.1038/s41561-017-0036-x
University of Tübingen
Faculty of Science
Geoscience Department - Isotope Geochemistry
Professor Dr. Ronny Schönberg
Phone +49 7071 29-78903
Dr. Benjamin Eickmann
Phone +49 7071 29-73156
Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
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Geoscientists have long presumed that, like today, the tropics remained warm throughout Earth's last major glaciation 300 million years ago.
New evidence, however, indicates that cold temperatures in fact episodically gripped these equatorial latitudes at that time.
Geologist Gerilyn Soreghan of Oklahoma University found evidence for this conclusion in the preservation of an ancient glacial landscape in the Rocky Mountains of western Colorado. Three hundred million years ago, the region was part of the tropics. The continents then were assembled into the supercontinent Pangaea.
Soreghan and colleagues published their results in the August 2008, issue of the journal Geology.
Climate model simulations are unable to replicate such cold tropical conditions for this time period, said Soreghan. "We are left with the prospect that what has been termed our 'best-known' analogue to Earth's modern glaciation is in fact poorly known."
"This study is an example of the wealth of untapped climate information stored in Earth's 'deep time' geologic record millions of years ago," said H. Richard Lane, program director in NSF's Division of Earth Sciences, which funded the research. "These kinds of discoveries may greatly improve our understanding and prediction of modern climate change."
As a result of the close proximity of the ancient tropical glaciers to the sea, the toes of the glaciers were likely less than 500 meters above sea level--much lower than the tropical glaciers of Earth's recent glacial times.
"The Late Paleozoic tropical climate was not buffered against cold from the high latitudes, as everyone had thought," said Soreghan. "The evidence we found indicates that glaciers were common at this time, even in tropical latitudes. This calls into question traditional assumptions of long-lasting equatorial warmth in the Late Paleozoic, and raises the possibility of large-scale and unexpected climate change in the tropics during that time."Media Contacts
Cheryl Dybas | EurekAlert!
New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz
Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Power and Electrical Engineering
17.07.2018 | Life Sciences
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All About Electricity and How It Works
Imagine what life would be like without electricity. No more computers or televisions. No more toasters or microwaves. Before electricity, people used candles and oil lamps for light. They used wood or coal to heat their homes. They used wooden boxes filled with ice to keep food cold.
But what is electricity? Electricity is a secondary energy. That means that it is made from other energies, such as coal, water or wind. Static electricity is electricity that doesn’t move. A bolt of lightning is caused by static electricity. Have you ever noticed sparks in your bed at night if you’re wearing fleece pajamas? As you move, static electricity builds up between the sheets and your pajamas. Current electricity is electricity that flows. This is the type of electricity that you have in your home.
Fun Facts about Electricity for Kids
- One flash of lightening could power 1000 houses for a whole year. Lightning lasts one second, but can create up to 3 million volts of electricity.
- Electricity travels at the speed of light, which is more than 186,000 miles per hour.
- In a power plant, electricity is made when steam from boiling water makes huge wheels spin in a turbine. Generators use the energy from the spinning wheels to make electricity. The boiling water can be fueled by coal, water or wind. Usually it is fueled by coal.
- Electricity comes from the power plant through underground or overhead lines to your home. It enters your home through a service box that keeps track of how much electricity you use. When you plug an appliance into an outlet in the wall, electricity flows into the appliance to make it work.
- Secondary: comes after something else
- Flow: moves
- Steam: water that has evaporated into a gas
Learn More All About Electricity and How It Works
Watch this video all about electricity:
A video about how electricity current flow works.
Question: Did Benjamin Franklin discover electricity?
Answer: Benjamin Franklin proved that lightning is a form of static electricity.
Question: Is electricity dangerous?
Answer: Electricity is very dangerous. It has the power to kill you. Never get close to power lines or stick your fingers in an electrical outlet.
Enjoyed the Easy Science for Kids Website all about Electricity info? Take the FREE & fun all about Electricity quiz and download FREE Electricity worksheet for kids. For lengthy info click here.
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One of the breakdown products of nitrogen metabolism is ammonia. However, ammonia is very toxic to tissues, and it must be excreted or removed as rapidly as it is formed. This presents no problem to many aquatic non-vertebrate organisms which simply excrete the ammonia to the surrounding water as it is formed. Terrestrial animals cannot do this, obviously; they and the marine fish could flush out the ammonia with a large volumes of urine but they must conserve water. How do they solve this dilemma? Thera are two principal ways of getting around this problem. Animals like man, that can afford to expend some water, detoxify ammonia to urea, which can be excreted with a moderate amount of water loss through the kidneys. Some animals, however, cannot afford to lose even that small amount of water; these include snakes and lizards, most birds, and insects. They convert ammonia to non-toxic uric acid which can be stored in the body for relatively long periods and can be excreted as a paste with little water or in a dry form with almost no water.
An animal may exrete nitrogen in various forms at different times during its life. For example, the tadpole, which is aquatic, excretes ammonia, but the adult frog, faced as it is with water loss through its very permeable skin, cannot spare enough water to exrete ammonia, and so it excretes urea. Interestingly the nitrogenous waste product which an animal excretes depends on where its embryo develops. Birds and reptiles develop in eggs which have tough, water-proof coverings; they can manage this because the embryo secretes non-toxic uric acid which can be stored until they animal hatches, and no harm is done. The embryos of man and of many other mammalian vertebrates that develop within the uterus excrete urea, which in turn is carried away from the placenta by the mother's blood to be excreted in water by the mother's kidneys. | <urn:uuid:237ce77a-83c2-4a93-a62e-0b8805856114> | 3.5625 | 410 | Knowledge Article | Science & Tech. | 37.842195 | 95,489,713 |
Comment your code ...
For any programmers, it is always strongly recommended to have explicit comments to strategic sections of the code. Commenting a code is very important for many reasons:
- It would serve as a valuable memory into what the particular code does. You may not know that down the line, after five years, when you see the code without comments, the same code might sound greek and latin.
- A good commented code can easily enable a peer developer to start maintaining it without bothering you for pesky queries on the same.
- Where possible, try using summary commenting like in JavaDoc and C# Xml commenting features.
When not to comment?
- If you are replacing a logic with another logic, do not comment the older logic and append the new one, as far as possible. That would only serve to increase the file size and complicate the maintainability of the code. To maintain history, use a good Source Control rather. | <urn:uuid:8820b89e-2135-4eed-8d85-1f00eb384053> | 2.53125 | 195 | Personal Blog | Software Dev. | 48.661722 | 95,489,724 |
Climate change, fishing and commercial shipping top the list of threats to the ocean off the West Coast of the United States.
"Every single spot of the ocean along the West Coast," said Ben Halpern, a marine ecologist at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California at Santa Barbara, "is affected by 10 to 15 different human activities annually."
In a two-year study to document the way humans are affecting the oceans in this region, Halpern and colleagues overlaid data on the location and intensity of 25 human-derived sources of ecological stress, including climate change, commercial and recreational fishing, land-based sources of pollution and ocean-based commercial activities.
With the information, they produced a composite map of the status of West Coast marine ecosystems.
The work was published online today in the journal Conservation Letters, and was conducted at NCEAS. NCEAS is primarily funded by NSF's Division of Environmental Biology.
"This important analysis of the geography and magnitude of land-based stressors should help focus attention on the hot-spots where coordinated management of land and ocean activities is needed," said Phillip Taylor, section head in NSF's Division of Ocean Sciences.
The lead scientists on the study conducted a similar analysis on a global scale; the results were published last year in Science.
By refining the methods used in the global study and applying them at a regional scale, the scientists were able to test how well the results predicted regional ocean health.
"We found two remarkable and unexpected results in this research," said Halpern.
"Ocean management needs to move beyond single-sector management and towards comprehensive ecosystem-based management if it is to be effective at protecting and sustaining ocean health.
"Also, the global results for this region were highly correlated with the regional results, suggesting that the global results can provide valuable guidance for regional efforts around the world."
The study results show that hotspots of cumulative impact are in coastal areas near urban centers and heavily polluted watersheds.
The research involved a four-step process.
First, the scientists gathered information to quantify and compare how different human activities affect each marine ecosystem. For example, fertilizer runoff was shown to have a large effect on salt marshes, but a much smaller one on rocky reefs.
Then the researchers gathered and processed data on marine ecosystems and human influences.
Next they combined data from the first and second steps to determine "human impact scores" for each location along the West Coast.
Finally, they compared regional results to global results for the same areas from the previous analysis.
"Comparing the global version of the map to regional-scale versions allows us to determine where it performs best," said biologist and paper co-author Kim Selkoe, also of NCEAS.
"The high correlation is good news for marine managers in areas of the world that may be in need of maps of human impacts, but don't have the resources to undertake their own tailored analysis."
The study provides critical information for evaluating where certain activities can continue with little effect on the oceans, and where other activities might need to be stopped or moved to less sensitive areas, said Taylor.
As management and conservation of the oceans turns toward marine protected areas (MPAs), ecosystem-based management (EBM), and ocean zoning to manage human influence, such information will prove invaluable to managers and policymakers, said Halpern.
"The results are a wake-up call," he said. "We are significantly affecting the oceans."
Cheryl Dybas | EurekAlert!
Further reports about: > Climate change > Coast > NCEAS > Pacific Ocean > commercial shipping > ecological stress > ecosystem-based management > fishing > human activities > human influence > land-based sources of pollution > marine ecosystem > ocean-based commercial activities > recreational fishing
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Materials Sciences
18.07.2018 | Life Sciences
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The idea of modeling the behaviour of phenomena at multiple scales has become a useful tool in both pure and applied mathematics. Fractal-based techniques lie at the heart of this area, as fractals are inherently multiscale objects; they very often describe nonlinear phenomena better than traditional mathematical models. In many cases they have been used for solving inverse problems arising in models described by systems of differential equations and dynamical systems. 'Fractal-Based Methods in Analysis' draws together, for the first time in book form, methods and results from almost twenty years of research in this topic, including new viewpoints and results in many of the chapters. For each topic the theoretical framework is carefully explained using examples and applications. The second chapter on basic iterated function systems theory is designed to be used as the basis for a course and includes many exercises. This chapter, along with the three background appendices on topological and metric spaces, measure theory, and basic results from set-valued analysis, make the book suitable for self-study or as a source book for a graduate course. The other chapters illustrate many extensions and applications of fractal-based methods to different areas. This book is intended for graduate students and researchers in applied mathematics, engineering and social sciences. Herb Kunze is a professor of mathematics at the University of Guelph in Ontario. Davide La Torre is an associate professor of mathematics in the Department of Economics, Management and Quantitative Methods of the University of Milan. Franklin Mendivil is a professor of mathematics at Acadia University in Nova Scotia. Edward Vrscay is a professor in the department of Applied Mathematics at the University of Waterloo inOntario. The major focus of their research is on fractals and the applications of fractals. | <urn:uuid:bcacff29-63ed-46c1-a903-030b6138f67d> | 2.59375 | 354 | Product Page | Science & Tech. | 21.122754 | 95,489,778 |
In order to better understand star formation, astronomers need telescopes that can observe at longer wavelengths, such as the submillimetre range, in which the dark dust grains shine rather than absorb light. APEX, on the Chajnantor Plateau in the Chilean Andes, is the largest single-dish submillimetre-wavelength telescope operating in the southern hemisphere, and is ideal for astronomers studying the birth of stars in this way.
A new image from the Atacama Pathfinder Experiment (APEX) telescope in Chile shows a beautiful view of clouds of cosmic dust in the region of Orion. While these dense interstellar clouds seem dark and obscured in visible-light observations, APEX’s LABOCA camera can detect the heat glow of the dust and reveal the hiding places where new stars are being formed. The image shows the region around the reflection nebula NGC 1999 in visible light, with the APEX observations overlaid in brilliant orange tones that seem to set the dark clouds on fire.
Credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Digitized Sky Survey 2
Located in the constellation of Orion (The Hunter), 1500 light-years away from Earth, the Orion Molecular Cloud Complex is the closest region of massive star formation to Earth, and contains a treasury of bright nebulae, dark clouds and young stars. The new image shows just part of this vast complex in visible light, with the APEX observations overlaid in brilliant orange tones that seem to set the dark clouds on fire. Often, the glowing knots from APEX correspond to darker patches in visible light -- the tell-tale sign of a dense cloud of dust that absorbs visible light, but glows at submillimetre wavelengths, and possibly a site of star formation.
The bright patch below of the centre of the image is the nebula NGC 1999. This region -- when seen in visible light -- is what astronomers call a reflection nebula, where the pale blue glow of background starlight is reflected from clouds of dust. The nebula is mainly illuminated by the energetic radiation from the young star V380 Orionis lurking at its heart. In the centre of the nebula is a dark patch, which can be seen even more clearly in a well-known image (http://www.spacetelescope.org/images/opo0010a/) from the NASA/ESA Hubble Space Telescope.
Normally, a dark patch such as this would indicate a dense cloud of cosmic dust, obscuring the stars and nebula behind it. However, in this image we can see that the patch remains strikingly dark, even when the APEX observations are included. Thanks to these APEX observations, combined with infrared observations from other telescopes, astronomers believe that the patch is in fact a hole or cavity in the nebula, excavated by material flowing out of the star V380 Orionis. For once, it truly is a hole in the sky!
The region in this image is located about two degrees south of the large and well-known Orion Nebula (Messier 42), which can be seen at the top edge of the wider view in visible light from the Digitized Sky Survey.
The APEX observations used in this image were led by Thomas Stanke (ESO), Tom Megeath (University of Toledo, USA), and Amy Stutz (Max Planck Institute for Astronomy, Heidelberg, Germany). APEX is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. Operation of APEX at Chajnantor is entrusted to ESO.
Douglas Pierce-Price | EurekAlert!
Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters
Theorists publish highest-precision prediction of muon magnetic anomaly
16.07.2018 | DOE/Brookhaven National Laboratory
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Transportation and Logistics
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In 1977, two years after declaring independence from Portugal, Mozambique erupted into civil war. Over the next 15 years, the violent conflict claimed at least a million lives—and that was just the humans.
Government troops and resistance fighters also slaughtered their way through the wildlife in the nation’s renowned Gorongosa National Park, once touted as a natural paradise. Thousands of elephants were hunted for their ivory, which was sold to buy arms and supplies. Zebras, wildebeest, and buffalo were killed for meat. Around 90 percent of the park’s large mammals were shot or died of starvation.
“They caused almost total collapse of the wildlife there,” says Joshua Daskin, an ecologist at Yale University who started working at Gorongosa in 2013.* “I wondered if that was a one-off, or emblematic of a wider trend.”
Spoiler: it’s the latter. Together with Rob Pringle, from Princeton University, Daskin compiled 65 years’ worth of data on the abundance of large mammals across all of Africa. These populations, they found, were stable during peacetime, but almost always fell during periods of war. And in explaining declines in wildlife, nothing mattered more than war—not human population density, the presence of towns or cities, protected reserves, or droughts.
“This speaks to the pervasive nature of conflict,” says Daskin. “It affects the ability, accountability, and motivation of governments to fulfil their conservation duties. It disturbs the fabric of local societies by increasing poverty, and displacing people into protected areas where they may harvest wildlife. It leads to withdrawal of NGOs. It increases problems with law enforcement, which might lead to increases in poaching.”
To make matters worse, as others have shown, war happens most often in places where wildlife otherwise flourishes. Between 1950 and 2000, 80 percent of major armed conflicts took place in biodiversity hotspots, where animal life is at its richest and most diverse. That, says Daskin, is because the same factors that cause peril for wildlife—climate change, the harvesting of natural resources, and fast-growing human populations—can also heighten tensions between people. And so, when people declare war on each other, they inadvertently declare war on the natural world.
That seems intuitive, but several case studies have shown that war can be a boon for the wild. The Rhodesian Bush War, in what is now called Zimbabwe, created an environment so hostile that poachers couldn’t operate—and elephant populations rebounded to decadal highs. The Korean Demilitarized Zone, which snakes between North Korea and South Korea, has become a de facto national park, since the absence of people means sanctuary for red-crowned cranes, Amur leopards, and other endangered species.
But for every tale of hope, there’s also one of doom. Animals can be collateral damage, sources of meat and money, or even political leverage. In Vietnam, the chemical weapons that the U.S. military used to denude the forests of vegetation left a toxic legacy for the nation’s jungle-dwellers. In Ethiopia, black-market weapons that were sold during the country’s civil war eventually made their way into the hands of poachers. In the Democratic Republic of Congo, rebels recently threatened to kill protected gorillas if the government took action against them.
It’s hard to work out the balance of these positive and negative anecdotes because, “as you might expect, ecologists tend to work in peaceful areas, so most of the wildlife counts haven’t been done in conflict zones,” says Daskin. But he and Pringle found whatever data they could: 253 time-trends, showing changes in the populations of 36 species in 126 protected areas. They then paired these counts with information on human fatalities from organized conflicts.
Protected areas vary a lot, but on average, Daskin and Pringle found that peaceful ones were stable and their animals self-sustaining. Warfare changed everything—and it didn’t really matter how violent the conflicts were. In fact, while the frequency of conflict was the most important of the factors the duo studied, the intensity of conflict was the least important. “It may not matter whether this is a small-scale battle or a large-scale war,” says Daskin. “The onset of conflict disrupts the ability to protect wildlife.”
Since people in war-torn areas “often rely heavily on wildlife, directly as food or as part of a healthy ecosystem,” says Kaitlyn Gaynor, from University of California, Berkeley, who has studied the issue, “wildlife declines may prolong the wars that caused them.”
At first glance, these seems like deeply defeatist findings. Conservationists are already overwhelmed and underfunded without having to add peace-keeping to their dockets. But Daskin and Pringle offer some good news, too: Even in places where people warred furiously, very few large animals actually went extinct. They took a pounding, but they were rarely knocked out. So, when conflicts cease, it’s possible to save the creatures that were harmed.
Consider Gorongosa National Park. “Most of the wildlife populations that were hanging on have recovered to incredible levels, some cases beyond pre-war sizes,” Daskin says. That’s largely because of a partnership between the government and the Gorongosa Restoration Project, a U.S.-based nonprofit.
In the post-war decades, the partnership has recruited and trained rangers to fight poachers. They deployed teams to boost the health of people who live near the park, through vaccinations, prenatal check-ups, family planning advice, and bed nets to block out malarial mosquitoes. They built four schools. They bring in more than 2,500 children a year to learn how to view wildlife as more than just sources of meat. “It’s about instilling a sense of ownership, and enabling the socioeconomic conditions for conservation to be possible,” says Daskin.
“There is incredible diversity in the nature of armed conflict and its effects on wildlife, and there is no one-size-fits-all solution,” says Gaynor. But the study clearly shows that “war-torn protected areas are not necessarily a lost cause for conservation. We ignore these areas to the peril of wildlife and, critically, to the detriment of vulnerable human populations that rely on healthy ecosystems.”
* This article previously misstated that Daskin is at Princeton and that Pringle is at Yale. We regret the error.
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Trees may not actually commit suicide, but certain species do produce pollutants that hamper their own growth while contributing to global climate changes and causing harm to other life forms, contend two Texas A&M University researchers.
Renyi Zhang, an atmospheric chemist, is studying one such substance, isoprene, given off by oak trees and leading to increased ozone in our atmosphere. Working under a $300,000 grant from the National Science Foundation, Zhang and chemistry professor Simon North have taken on the challenge of unraveling the more than 1,000 reactions that transform organically released isoprene into toxic atmospheric pollutants.
"Air pollution is probably one of the most serious problems facing humankind in the 21st century," said Zhang, a professor in the College of Geosciences. "And certainly, much of that pollution results from human activities. But most people are not aware of the role played by chemical reactions which change substances produced by biogenic species into harmful airborne pollutants.
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For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
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Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
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Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
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Insects. You can't beat them. You can barely hope to contain them. Occasionally.
And it's just as well, for insects have sunk their segmented appendages into every natural racket worth playing, from pollination to waste disposal. Perhaps you've heard the buzz about hive collapse? We're not freaking out because we love honey (well, not only because we love honey). We're worried because Colony Collapse Disorder could threaten global agriculture.
So it's just as well that insects, as a group, are born survivors. Take the cockroach (please). Tests have shown they can survive insults ranging from a month's worth of Hiroshima-level radiation to literally losing their heads [source: Choi]. When sugar-laced roach bait began leading common German cockroaches to their collective doom, their brains developed an aversion to glucose — in just a few generations [source: Wada-Katsumata, Silverman and Schal].
But cockroaches are just the classic case of this invertebrate class's knack for survival. From the dawn of land-based life, insects have been nature's great explorers and colonizers. They are adaptive, mutable pioneers that have evolved to fill nearly every terrestrial niche, and they are legion.
Here are 10 traits that make insects thrive when other animals can't.
If you want to survive, it helps to be flexible. Eat what's available, time your bodily cycles to local conditions and don't put all of your eggs in one ecological basket. As a class, insects are masters of flexibility, both in terms of genetic adaptation and phenotypic plasticity — the way one set of genes can produce physical traits that vary in response to diverse environments [source: Whitman and Agrawal].
Insects account for nearly 73 percent of all known animal species and for almost 85 percent of land animal species. So far, we've found and named around 900,000 species, divided into 32 orders. Experts estimate that the true number could reach much higher, in the range of 2-30 million [sources: Danforth, Smithsonian]. The larger estimate derives in part from the amazing variety of insects that dwell in South American forest canopies [source: Smithsonian].
Their wide ranges of physical and social traits, and their notable adaptability, enable insects to spread into nearly every open niche. It also partly explains why insects survive mass extinctions [source: Yeates]. But even creatures as flexible as insects require a lot of time to radiate into so many wondrous forms.
The same factors that drive insects to branch out into species today have also driven large-scale changes in the distant past. These include mutation, natural selection, migration, isolation and genetic drift, the tendency of some offspring, and their genes, to survive due to random forces not related to adaptation. However, the rise of such new clades, or groups of species, like bees or beetles, requires far longer stretches of evolutionary time [source: UC Berkeley].
Insects first appeared at least 450-500 million years ago. Their ancestors evolved from crustaceans, and the earliest creatures that we'd recognize probably looked like modern silverfish (Lepisma saccharina). A major flowering of species 100-150 million years later produced grasshoppers and cockroaches. Insect groups like flies, wasps and beetles made the scene around 200 million years ago [sources: Misof et al., Yeates].
Each group represents specializations made possible by large spans of time. Over eons, the clades radiated into species adapted to numerous land and freshwater niches [source: Misof et al.]. This process profited not only from time, but also from the survival value of high fertility rates and large broods in many species.
Population-wise, we might as well dispense with the idea that we run the planet. A population of 7 billion might sound large to us endoskeletal bipeds, but it's peanuts next to roughly 10 quintillion (10,000,000,000,000,000,000) living insects. The population of the United States measures around 320 million. Some soil studies have found that many insects in a singleacre [source: Smithsonian].
For insects with high mortality rates, fecundity means survival. But bountiful babies offer evolutionary perks as well. Large populations help insects make the most of new niches and prospects. They also help insects develop resistances to whatever bug juice we throw at them. Fitness traits develop through random favorable mutations, and large populations mean large numbers of tickets in the genetic lottery [source: Yeates].
In addition, population pressures push insects to spread out. More geographic isolation and less gene flow from one end of the populace to the other helps to bring about new species. For existing species, large populations help ensure stability by lessening the impact of genetic drift [source: UC Berkeley]. They also face fierce rivalry within their ranks, a problem some insects deal with using a little social engineering [source: Capinera].
Evolutionarily speaking, insects pioneered social structures [source: Misof et al.]. Today, the 2 percent of known species that have this trait make up roughly four-fifths of the planet's insect biomass [source: Johnson and Carey]. What's more, taken together, their ecological impact can outclass just about any other animal. South American leafcutter ants, for example, chow down on more plant life than all plant-eating mammals on that continent combined [source: Meyer].
True social, or eusocial, species share four key traits. Their members occupy a shared nest site; team up to raise young; split labor between sterile (or less fecund) workers and reproducers; and live side by side with overlapping generations. Although many insect species have one, two or even three of these traits, only a few have them all. They include all termites, all ants, 600 species of bees (family Apidae) and 700 species of wasps (family Vespidae) [source: Meyer].
Of course, social structures carry risk. Infectious diseases and specialized parasites can wreak more havoc, and members must vie with one another for resources. But weighed against a large, expert and robust workforce for building, food gathering and defense, the rewards of a large social populace become clear.
The jointed limb quite literally defines the phylum to which insects belong. It's right there in the name Arthropoda (from Greek arthros (jointed) and poda (foot)). But in insects, these members form more than just limbs. They are the basis for everything from antennae to mouthparts [sources: Fleury, Wigglesworth].
Insects likely evolved from a critter made up of numerous similar leg-bearing segments, not unlike a simple centipede. Over time, these parts fused to form the familiar head, abdomen and thorax of modern insects, while their connected legs changed to take on roles from sensing to stinging. An insect's head, for example, consists of six primitive segments, the modified legs of which now serve as antennae and specialized mouthparts [sources: Fleury, Wigglesworth].
And we do mean specialized. If you think a shrimp fork is a specific utensil, try mouthparts with cutting edges, or with tubes and grooves that assist both bloodsuckers and nectar-feeders [source: Wigglesworth; Mitchell and Scott].
One all-or-nothing approach to survival is to become essential to something else, to bind your fates so tightly that you live or die as one. In nature, such mutualism can entail risks, but it can also pay dividends by securing food and shelter for insects and their offspring. Mutualism takes many forms, the most extreme of which, coevolution, involves species influencing each other's evolution.
Insects and plants do not have a monopoly on coevolution or mutualism, but genetic research suggests that they have evolved in tandem virtually from the beginning [source: Misof et al.]. This long history has led to numerous hand-in-glove relationships between the two. Acacia ants live in the thorns of acacias and protect them from herbivores, while the trees' leaf tips provide food for the ants. Yucca flowers, for example, have shapes that only allow the yucca moth to pollenate them. After pollenating, females lay egg in the yucca. When they hatch, her caterpillars will eat some of the seeds but leave enough for rodents to disperse [source: Carter].
Enduring drastic changes as you grow might sound like a giant hassle — most of us can barely hack puberty — but it offers its share of benefits.
Most insects undergo major changes in their bodies, biochemical makeup and behavior as they mature. Primitive insects go through a partial metamorphosis in which a few body parts, such as sex organs, mature over time. In such species, juveniles and adults bear some resemblance. Advanced insects, conversely, go through a change so complete that they appear at some stages to be different animals. In the larval stage, their bodies are built to chow down and beef up. Later, they assume an inactive transitional form, or pupa, that tears them down and reshapes them into an adult body built for spreading out and making babies [sources: Meyer, Museum Victoria].
Complete metamorphosis means that juveniles face different predators and don't vie with adults for food. It's a useful way to spread the odds. Perhaps that why, although only nine out of 28 orders go through it, they account for 86 percent of all insect species [sources: Meyer, Museum Victoria].
Insects developed wings around the same time plants began growing upward — more than 100 million years before the first reptiles flew [sources: Meyer, Yeates]. The closest modern equivalents to these pioneers of flight are mayflies and dragonflies, although ancient dragonflies sported 24- to 28-inch (60- to 70-centimeter) wingspans [source: Yeates]!
Flight helps insects spread into new areas, migrate, escape predators and reach out-of-the-way food sources. Some sportier models of insect come equipped with foldable wings, a handy trait for squeezing into tight spaces like nests or tunnels [source: Danforth].
Insects are the only invertebrates that fly. They're also the only winged animals that did not give up a set of limbs in order to gain wings [sources: Meyer, Yeates]. The speed and agility they display in flight, the heavy loads they can carry, and the strange flight mechanics involved continue to inspire research by physicists and aeronautical engineers [source: Meyer].
When flying, insects use about as much energy (calories per unit of lift) as do birds and bats, but they excel at converting that energy into power. Insects store and release energy with spring-like efficiency because their bodies are both flexible and resilient, thanks in part to their exoskeletons [source: Meyer].
Instead of bones, insect bodies are supported by a skeleton that covers their outsides. This exoskeleton consists chiefly of chitin, a substance that can take forms raging from rubbery to rigid and from supple to steely. It not only protects the insect from damage or drying out, it also houses sensory organs, includes breathing holes called spiracles and, like our skeletons, provides a place for muscles to attach [sources: Encyclopedia Britannica, Meyer].
Exoskeletons also account for insects' notable strength and flexibility. Fixing internal muscles to an outer body wall instead of an inner skeleton boosts mechanical advantage, which partly explains why many insects can heft loads that weigh many times their own body weight. Insect bodies remain flexible thanks to supple tissues at the plate joints, and their internal squishiness lets them squeeze into small spaces to escape predators, seek food or hide from the elements [source: Meyer].
Like most adaptive features, exoskeletons have drawbacks. When an insect grows, its shell stays the same size, so it must shed it in a process called molting. After molting, the insect remains at risk until a new exoskeleton forms [sources: Encyclopedia Britannica]. Exoskeletons also limit how large insects can grow — in time, the need for more muscle outstrips available attachment areas — but that's just as well, because being small has survival value, too.
Insects push the boundaries of smallness. Midnight movies to the contrary, there's only so large an exoskeleton-based creature can grow — theoretically, around 4-5 ounces (125-150 grams) [source: Meyer]. The largest living insect, the cricket-like New Zealand giant wētā, or wētāpunga, weighs about half that (but still outweighs a mouse or a sparrow!) [sources: NZDoC, The Telegraph [UK]].
One the smaller end of the scale, insects are wonders of miniaturization. Shakespeare's Hamlet spoke figuratively when he said, "I could be bounded in a nutshell, and count myself a king of infinite space." But some ant species establish entire colonies inside of acorns [sources: CISEO; Meyer]. Moreover, the smallest insects, such as the Costa Rican wasp Dichomorpha echmepterygis, can reach sizes smaller than some paramecium (single-celled protozoa) — 0.00055 inch or 0.139 millimeters. The majority of insects fall into the 0.1-1.0 inch (2-20 millimeter) range [source: Meyer].
Tiny creatures enjoy several advantages. They need only the tiniest morsel or drop to sustain their bodily needs, hide from predators in nearly any setting and find shelter and shade wherever they might be. To them, a pebble is a boulder and a tiny crack, a fissure. You might say that, for insects, the world is incredibly small and therefore unspeakably vast.
These parasitic wasps eat their hosts from the inside. HowStuffWorks takes a look.
Author's Note: 10 Traits That Make Insects Survivors
It's so very easy to get lost in the small yet vast universe of insects. With so many species and so varied a range of adaptations, you just want to read on and on, or to shrink yourself down and experience just for a moment what their splendid and multifarious universe must be like.
More Great Links
- Capinera, John L. "Encyclopedia of Entomology, Volume 4." Springer Science & Business Media. Aug 11, 2008.
- Carter, J. Stein. "Coevolution and Pollination." University of Cincinnati Clermont College. March 29, 2005. (May 1, 2015) http://biology.clc.uc.edu/courses/bio303/coevolution.htm
- Center for Insect Science Education Outreach. "Ant Information." University of Arizona. 1997. (May 4, 2015) http://insected.arizona.edu/antinfo.htm
- Choi, Charles. "Fact or Fiction?: A Cockroach Can Live Without Its Head." Scientific American. March 15, 2007. (May 6, 2015) http://www.scientificamerican.com/article/fact-or-fiction-cockroach-can-live-without-head/
- Danforth, Bryan. "Insect Diversity." Cornell University Department of Entomology. (May 4, 2015) https://courses.cit.cornell.edu/ent201/diversity.html
- Danforth, Bryan. "Handout — Insect Orders and the Timeline of Insect Evolution." Cornell University Department of Entomology. (May 4, 2015) https://courses.cit.cornell.edu/ent201/content/diversity.pdf
- Encyclopedia Britannica. "Exoskeleton." Children's Encyclopedia. (May 8, 2015) http://kids.britannica.com/elementary/article-399448/exoskeleton
- Fleury, Bruce E. "Arthropods." Tulane University Department of Ecology and Evolutionary Biology. (May 4, 2015) http://www.tulane.edu/~bfleury/diversity/labguide/arthropod.html
- Johnson, Brian and James R. Carey. "Hierarchy and Connectedness as Determinants of Health and Longevity in Social Insects." Sociality, Hierarchy, Health: Comparative Biodemography: A Collection of Papers. National Academies Press. 2014. (May 6, 2015) http://www.ncbi.nlm.nih.gov/books/NBK242457/
- Meyer, John R. "A Class of Distinction: Reasons for Success." North Carolina State University Department of Entomology. Jan. 21, 2007. (May 1, 2015) http://www.cals.ncsu.edu/course/ent425/text01/success.html
- Meyer, John R. "Social Insects." North Carolina State University Department of Entomology. March 16, 2005. (April 27, 2015) http://www.cals.ncsu.edu/course/ent425/tutorial/Social/
- Misof, Bernhard, et al. "Phylogenomics Resolves the Timing and Pattern of Insect Evolution." Science. Vol. 346, no. 6210. Page 763. Nov. 7, 2014. (April 27, 2015) http://www.sciencemag.org/content/346/6210/763
- Mitchell, B. K. and J. S. Scott. "An Introduction to Insect Structure." Department of Biological Sciences, University of Alberta. (May 4, 2015) http://www.biology.ualberta.ca/mitchell.hp/Structure/modules.pdf
- Museum Victoria. "Life Cycles." (May 1, 2015) http://museumvictoria.com.au/bugs/life/cycles.aspx
- Mythbusters. "Cockroaches Survive Nuclear Explosion." From MythBusters: Airplane on a Conveyor Belt.Jan. 30, 2008. (May 6, 2015) http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/cockroaches-survive-nuclear-explosion/
- New Zealand Department of Conservation. "Giant Wētā / Wētāpunga." (May 1, 2015) http://www.doc.govt.nz/nature/native-animals/invertebrates/weta/giant-weta-wetapunga/
- Smithsonian Institution. "Information Sheet Number 18: Numbers of Insects (Species and Individuals)." Department of Systematic Biology, Entomology Section, National Museum of Natural History. (May 4, 2015) http://www.si.edu/encyclopedia_si/nmnh/buginfo/bugnos.htm
- The Telegraph [UK]. "World's Biggest Insect is So Huge It Eats Carrots." Dec. 1, 2011. (May 1, 2015) http://www.telegraph.co.uk/news/earth/wildlife/8930070/Worlds-biggest-insect-is-so-huge-it-eats-carrots.html
- University of California, Berkeley. "Evolution 101. Understanding Evolution." (May 6, 2015) http://evolution.berkeley.edu/evolibrary/article/evo_01
- Wada-Katsumata, Ayako, Jules Silverman and Coby Schal. "Changes in Taste Neurons Support the Emergence of an Adaptive Behavior in Cockroaches." Science. Vol. 340, no. 6135. Page 972. May 24, 2013. (May 8, 2015) http://www.sciencemag.org/content/340/6135/972
- Whitman, Douglas W., and Anurag A. Agrawal. "What is Phenotypic Plasticity and Why is It Important." Phenotypic Plasticity of Insects. Vol. 10. Page 1. 2009 (May 8, 2015) http://www.eeb.cornell.edu/agrawal/pdfs/whitman-and-agrawal-2009-Ch_1-Phenotypic-Plasticity-of-Insects.pdf
- Wigglesworth, Vincent B. "Insect: Head." Encyclopedia Britannica. July 20, 2014. (May 4, 2015) http://www.britannica.com/EBchecked/topic/289001/insect/41285/Head
- Yeates, David. "Insects Are the Great Survivors in Evolution: New Study." The Conversation. Nov. 6 2014. (April 27, 2015) http://theconversation.com/insects-are-the-great-survivors-in-evolution-new-study-33786 | <urn:uuid:7073a473-424c-4557-801a-6202bb5a3f9c> | 3.59375 | 4,456 | Listicle | Science & Tech. | 53.569876 | 95,489,802 |
The most intense burst of solar radiation in five decades accompanied a large solar flare on January 20. It shook space weather theory and highlighted the need for new forecasting techniques, according to several presentations at the American Geophysical Union meeting this week in New Orleans.
The solar flare, which occurred at 2 a.m. EST, tripped radiation monitors all over the planet and scrambled detectors on spacecraft. The shower of energetic protons came minutes after the first sign of the flare. This flare was an extreme example of the type of radiation storm that arrives too quickly to warn interplanetary astronauts.
"This flare produced the largest solar radiation signal on the ground in nearly 50 years," said Dr. Richard Mewaldt of the California Institute of Technology, Pasadena, Calif. He is a co-investigator on NASA's Advanced Composition Explorer (ACE) spacecraft. "But we were really surprised when we saw how fast the particles reached their peak intensity and arrived at Earth."
Normally it takes two or more hours for a dangerous proton shower to reach maximum intensity at Earth after a solar flare. The particles from the January 20 flare peaked about 15 minutes after the first sign.
"That's important because it's too fast to respond with much warning to astronauts or spacecraft that might be outside Earth's protective magnetosphere," Mewaldt said. "In addition to monitoring the sun, we need to develop the ability to predict flares in advance if we are going to send humans to explore our solar system."
The event shakes the theory about the origin of proton storms at Earth. "Since about 1990, we've believed proton storms at Earth are caused by shock waves in the inner solar system as coronal mass ejections plow through interplanetary space," said Professor Robert Lin of the University of California at Berkeley. He is principal investigator for the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). "But the protons from this event may have come from the sun itself, which is very confusing."
The origin of the protons is imprinted in their energy spectrum, as measured by ACE and other spacecraft, which matches the energy spectrum of gamma-rays thrown off by the flare, as measured by RHESSI. "This is surprising because in the past we believed the protons making gamma-rays at the flare were produced locally and the ones at the Earth were produced instead by shock acceleration in interplanetary space," Lin said. "The similarity of the spectra suggests they are the same."
Solar flares and coronal mass ejections (CMEs), associated giant clouds of plasma in space, are the largest explosions in the solar system. They are caused by the buildup and sudden release of magnetic stress in the solar atmosphere above the giant magnetic poles we see as sunspots. The Transitional Region and Coronal Explorer (TRACE) and the Solar and Heliospheric Observatory (SOHO) spacecraft are devoted to observing the sun and identifying the root causes of flares and CMEs, with an eye toward forecasting them.
"We do not know how to predict the flow of energy into and through these large flares", said Dr. Richard Nightingale of the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alta, Calif. "Instruments like TRACE give us new clues with each event we observe."
TRACE has identified a possible source of the magnetic stress that causes solar flares. The sunspots that give off the very largest (X-class) flares appear to rotate in the days around the flare. "This rotation stretches and twists the magnetic field lines over the sunspots", Nightingale said. "We have seen it before virtually every X-flare that TRACE has observed since it was launched and more than half of all flares in that time."
However, rotating sunspots are not the whole story. The unique flare came at the end of a string of five other very large flares from the same sunspot group, and no one knows why this one produced more sudden high energy particles than the first four.
"It means we really don't understand how the sun works," Lin said. "We need to continue to operate and exploit our fleet of solar-observing spacecraft to identify how it works."
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You may have heard, that the first total solar eclipse visible from the United States in 26 years will be seen in much of the country on August 21.
While Connecticut is not in the prime viewing path, interest and anticipation is rising even in the Land of Steady Habits due to the unusual nature of the occurrence.
For the uninitiated, an article appearing in the latest on-line edition of the website Massive explains that “During a total solar eclipse, the moon covers the bright disk of the sun. If the sun were a perfect sphere, it would disappear entirely, plunging the viewer temporarily into full darkness. But beyond the surface of the sun extends the corona. Full of beautiful loops and streamers, the corona is normally invisible against the blinding light of the full sun.”
The article was written by Jesse Feddersen, a 4th year PhD Candidate in the Department of Astronomy at Yale University. In addition to his academic research and teaching work, for the past two years he has been presenting live planetarium shows to the public at Yale University’s Leitner Family Observatory.
Feddersen notes that “because of its path over populated areas, the August eclipse will likely be the most viewed in history. Two teams plan to exploit this fact to coordinate observations across the United States,” in order to “combine images from 60 telescopes along the track of the eclipse.” It can best be seen along a path from Oregon to South Carolina.
“The continuous view of the darkened Sun,” he adds, “will create a data set for researchers to study.”
It is precisely that connection – between regular citizens and scientific experts – that is behind the launch of the Massive website late last year. As the founders describe their mission, “we work directly with researchers to transform papers in their field from complex, technical documents into stories that anyone – including other scientists – can understand and enjoy. We focus on eliminating jargon, adding storytelling and perspective, and teasing out the big questions the research is asking without sacrificing depth.”
Put most succinctly, the website headlines, “Everyone should have access to science.” Towards that end, they’re in the midst of enlisting “a group of scientists dedicated to making science accessible to everyone,” by forming the “Massive Science Consortium.”
Recent articles include contributions from a molecular pharmacologist, a genetics expert, a biochemist, and a botanist. The site offers free subscriptions to its newsletter, which highlights contributions from scientists in a range of fields worldwide.
The three founders – Nadja Oertelt, Gabe Stein and Allan Lasser – have added a veteran journalist who got her start in Connecticut to work directly with scientists in editing their work for a mainstream audience. Kira Goldenberg, who had stints with the Hartford Courant and New London Day earlier in her career, has more recently been a leading staffer at The Guardian and Columbia Journalism Review. She joins Massive as Editorial Director, energized by the potential of the fledgling venture.
“I’ve helped academics and reporters edit and hone their writing for the public as an editor at The Guardian and at the Columbia Journalism Review. I love working with people to make their writing the best it can possibly be,” she says on the Massive website.
Massive is a for-profit company funded by Bloomberg Beta, General Electric, and individual investors. The founders explain the motivation that inspired the venture: “We believe the world would be a better place if more people understood and trusted science, and used scientific reasoning to make sense of their world. With notable exceptions, we think that most of today’s science journalism and science communication efforts fall short of advancing this goal.”
The Massive team aims to combine “the storytelling and audience development techniques of a media company with the accuracy and authority of professional scientists and science communicators.”
That the first total solar eclipse visible in the U.S. in a quarter-century happens to occur during their first year of operations was, although not unexpected, largely coincidental.
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A new map of Mars' gravity made with three NASA spacecraft is the most detailed to date, providing a revealing glimpse into the hidden interior of the Red Planet.
"Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient," said Antonio Genova of the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts.
"The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet's gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars. Furthermore, the improved resolution of our gravity map will help us understand the still-mysterious formation of specific regions of the planet."
Genova, who is affiliated with MIT but is located at NASA's Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of a paper on this research published online March 5 in the journal Icarus.
The improved resolution of the new gravity map suggests a new explanation for how some features formed across the boundary that divides the relatively smooth northern lowlands from heavily cratered southern highlands.
Also, the team confirmed that Mars has a liquid outer core of molten rock by analyzing tides in the Martian crust and mantle caused by the gravitational pull of the sun and the two moons of Mars. Finally, by observing how Mars' gravity changed over 11 years - the period of an entire cycle of solar activity -- the team inferred the massive amount of carbon dioxide that freezes out of the atmosphere onto a Martian polar ice cap when it experiences winter. They also observed how that mass moves between the south pole and the north pole with the change of season in each hemisphere.
The map was derived using Doppler and range tracking data collected by NASA's Deep Space Network from three NASA spacecraft in orbit around Mars: Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). Like all planets, Mars is lumpy, which causes the gravitational pull felt by spacecraft in orbit around it to change. For example, the pull will be a bit stronger over a mountain, and slightly weaker over a canyon.
Slight differences in Mars' gravity changed the trajectory of the NASA spacecraft orbiting the planet, which altered the signal being sent from the spacecraft to the Deep Space Network. These small fluctuations in the orbital data were used to build a map of the Martian gravity field.
The gravity field was recovered using about 16 years of data that were continuously collected in orbit around Mars. However, orbital changes from uneven gravity are tiny, and other forces that can perturb the motion of the spacecraft had to be carefully accounted for, such as the force of sunlight on the spacecraft's solar panels and drag from the Red Planet's thin upper atmosphere. It took two years of analysis and computer modeling to remove the motion not caused by gravity.
"With this new map, we've been able to see gravity anomalies as small as about 100 kilometers (about 62 miles) across, and we've determined the crustal thickness of Mars with a resolution of around 120 kilometers (almost 75 miles)," said Genova. "The better resolution of the new map helps interpret how the crust of the planet changed over Mars' history in many regions."
For example, an area of lower gravity between Acidalia Planitia and Tempe Terra was interpreted before as a system of buried channels that delivered water and sediments from Mars' southern highlands into the northern lowlands billions of years ago when the Martian climate was wetter than it is today. The new map reveals that this low gravity anomaly is definitely larger and follows the boundary between the highlands and the lowlands. This system of gravity troughs is unlikely to be only due to buried channels because in places the region is elevated above the surrounding plains. The new gravity map shows that some of these features run perpendicular to the local topography slope, against what would have been the natural downhill flow of water.
An alternative explanation is that this anomaly may be a consequence of a flexure or bending of the lithosphere -- the strong, outermost layer of the planet -- due to the formation of the Tharsis region. Tharsis is a volcanic plateau on Mars thousands of miles across with the largest volcanoes in the solar system. As the Tharsis volcanoes grew, the surrounding lithosphere buckled under their immense weight.
The new gravity field also allowed the team to confirm indications from previous gravity solutions that Mars has a liquid outer core of molten rock. The new gravity solution improved the measurement of the Martian tides, which will be used by geophysicists to improve the model of Mars' interior.
Changes in Martian gravity over time have been previously measured using the MGS and ODY missions to monitor the polar ice caps. For the first time, the team used MRO data to continue monitoring their mass. The team has determined that when one hemisphere experiences winter, approximately 3 trillion to 4 trillion tons of carbon dioxide freezes out of the atmosphere onto the northern and southern polar caps, respectively. This is about 12 to 16 percent of the mass of the entire Martian atmosphere. NASA's Viking missions first observed this massive seasonal precipitation of carbon dioxide. The new observation confirms numerical predictions from the Mars Global Reference Atmospheric Model - 2010.
The research was funded by grants from NASA's Mars Reconnaissance Orbiter mission and NASA's Mars Data Analysis Program.
Bill Steigerwald | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Materials Sciences
19.07.2018 | Earth Sciences
19.07.2018 | Life Sciences | <urn:uuid:0db85fe8-0564-42cc-ba02-75a95059aaae> | 4.09375 | 1,731 | Content Listing | Science & Tech. | 39.822697 | 95,489,824 |
At the time of its discovery, 2018 LA was nearly as close to Earth as the orbit of the moon, "although that was not initially known", stated NASA officials.
Asteroid trackers at NASA and elsewhere quickly determined the rock - about 6 feet across (2 meters) - was too small to pose any danger. Here's how to know for sure!
This is only the third time that an asteroid with an impact trajectory has been discovered, and only the second time that such a "high level of probability of an impact was predicted well ahead of the event itself", according to Paul Chodas, manager for CNEOS.
The small, Earth-bound asteroid discovered this weekend is no longer a threat. That trajectory plot was the first hint that 2018 LA could hit Earth. It appeared as a bright streak coming in force with a spectacular fireball.
Ronaldo joins Portugal camp ahead of World Cup
As for a new potential team, a stunning return to Manchester United remains muted not to mention the French champions. As a result, he's angry and disappointed to the point he's looking for an exit.
Astronomers need long-term data to accurately determine the trajectory of asteroids and, as 2018 LA had just been identified, they didn't have much to go on.
Only twice before has a small asteroid been detected hours before colliding with Earth.
Asteroids Are big debris left over from the creation of the solar system.
One such larger object was the asteroid that went completely undetected until it collided with the atmosphere over Russian Federation in 2013, creating a shock wave that blew out thousands of windows in the town of Chelyabinsk ans caused a number of injuries.
While there is a good chance of finding meteorites on the ground from the impact of 2018 LA, any fragments of the asteroid that made it to the surface would have been slowed considerably by their interaction with the atmosphere. Hours later, it struck the atmosphere. It would most certainly hurt if someone was unlucky enough to be hit by one of these, but it's unlikely to cause a serious injury. Only two other instances come to mind, according to JPL. However, the asteroid of 2008 was detected nineteen hours before it struck the sky over Sudan.
Smaller objects are fainter and more hard to spot in a large sky, though efforts like the NASA-funded Catalina Sky Survey are increasingly able to search a wider field of sky to find these somewhat elusive objects. Luckily, 2014 AA struck over the Atlantic Ocean, thousands of miles away from the nearest landmass, Sky & Telescope reported at the time. | <urn:uuid:879ed861-02f7-498a-8c42-0c853e5bda86> | 3.1875 | 531 | News Article | Science & Tech. | 47.560463 | 95,489,833 |
Nutrient Dynamics of a Human-Impacted Pine Forest in a MAB Reserve of Subtropical China
- Jiangming Mo, Sandra Brown, Melanie Lenart, Guohui Kong
- Biotropica SCI(E) SCOPUS
- in 1995
- Cited Count
The effects of litter and understory harvesting by local people on the nutrient cycle in a pine forest in Dinghushan Biosphere Reserve (DHSBR) of subtropical China were studied by quantifying nutrient distribution, recycling, and loss in the ecosystem. The total nutrient standing stocks were estimated to be 2066 kg ha-1for N, 282 kg ha-1for P, 541 kg ha-1for K, 491 kg ha-1for Ca, and 151 kg ha-1for Mg. Most of these nutrients were contained in the top 10 cm of soil (72 to 94%). The total quantity of nutrients in the production of litterfall and understory were: 43.5 kg ha-1yr-1for N, 1.7 kg ha-1yr-1for P, 16.1 kg ha-1yr-1for K, 10.9 kg ha-1yr-1for Ca, and 2.7 kg ha-1yr-1for Mg. The harvest practice removed substantial quantities of these nutrients, 44 to 73 percent of the amount in litter and understory production, a rate that appeared to exceed most nutrient inputs from atmospheric deposition. In addition to the direct removal of nutrients, the harvest practice also reduced the active soil organic matter pool thus reducing nutrient mineralization and soil nutrient availability. An alternative system of tree harvest and replanting, combined with litter removal only, was proposed that reduced by one-third or more the present nutrient removals.
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This article discusses Perl/Tk’s Tk::Tree widget, which displays hierarchical data in a tree format. In computer science, a tree is a data structure that starts at a root node and branches to other nodes, which can be internal nodes or leaf nodes at the bottom of the tree. An internal node has one or more child nodes; it’s called the parent of those nodes. (Any child node at the end of a branch is a leaf node, since it has no children.) Nodes sharing the same parent are siblings. Unlike a physical tree, the root node is usually shown at the top, and leaves at the bottom of the structure. See Figure 40-1.
Figure 40-1. A sample tree
In contrast, Tk::Tree draws “sideways” trees, with the root node at the top left and branches growing down and to the right. While Tk::Tree is in the standard Perl/Tk distribution, there’s another tree widget on CPAN: Tk::TreeGraph, by Dominique Dumont. I won’t describe it here, but Figure 40-2 shows it, and you can read about it on the Perl/Tk modules page http://www.Lehigh.EDU/~sol0/ddumont/ptk_module_list.html.
Tk::Tree is derived from Tk::HList, the hierarchical list widget. From a programming point of view, Tree is much simpler to use because it masks the complexity of HList and automatically adds open and close buttons, thus exposing a much simpler interface. Figure 40-3 (interestingly enough, ... | <urn:uuid:dd644532-4504-4681-9709-65cf81ca7be5> | 3.828125 | 347 | Truncated | Software Dev. | 71.559664 | 95,489,846 |
Writing in the August 2012 issue of the journal BioScience, the researchers argue that ecology experts should be among scientists given independent authority and adequate funding to explore any potential unintended consequences of this technological pursuit.
A critical baseline concern is whether genetically engineered algae would be able to survive in the wild, said Allison Snow, professor of evolution, ecology and organismal biology at Ohio State University and lead author of the paper.
“If they’re grown in big, open ponds, which is mainly what were talking about, could the newer types of microalgae get out into nature and mingle? We need to know if they can survive and whether they can hybridize or evolve to become more prolific when they get out of a controlled environment,” Snow said.
“If they can survive, we also need to know whether some types of genetically engineered blue-green algae, for example, could produce toxins or harmful algal blooms - or both,” Snow noted.
And because algae are so small and could be dispersed by rough weather or wildlife activity, biologists worry that any transgenes they contain to enhance their growth and strength could be transferred to other species in a way that could upset a fragile ecosystem.
“The applications are new and the organisms are less well-known. They range from being very tame ‘lab rats’ that won’t survive in nature to wild organisms that can presumably cross with each other unless some measures are taken to prevent crossing. It’s a very new situation,” Snow said.
Snow co-authored the article with aquatic ecologist Val Smith, a professor in the Department of Ecology and Evolutionary Biology at the University of Kansas.
Snow has a history in this area of research. She led a study in 2002 that was the first to show that a gene artificially inserted into crop plants to fend off pests could migrate to weeds in a natural environment and make the weeds stronger. She also has served on national panels that monitor and make recommendations about the release of genetically engineered species into the environment.
There are a lot of unknowns about this area of research and development in microalgae, and that’s largely because algae don’t have the breeding history that, say, corn and soybeans have, Snow said. In addition, few details are publicly available because much of this information remains confidential as businesses compete to be the first to commercialize their genetically altered algae.
“We’re hoping to reach several audiences - including ecologists, molecular biologists and biotech business owners - and bring them together. There’s a community of people like me who study genetically engineered crops and how they interact with the environment, and we need to get this started with algae.
“There’s a lot of hype and speculation about algae as a biofuel source, and it’s hard to gauge exactly what’s going on. We see many indications, especially funding, that private companies and the government have decided this is important and worth pursuing,” Snow said. “So much will depend on the economics of it. Whether you can get a lot of energy out of algae depends on these breakthroughs with biology, technology, or both.”
In the same way that certain crop plants are bred with genes to help them repel pests and tolerate harsh conditions, different species of algae are likely being genetically engineered to grow rapidly because mass quantities of these tiny species will be needed to produce adequate fuel supplies.
The authors recommend, for starters, a comparative examination of genetically engineered algae strains intended for large-scale cultivation with their natural counterparts to determine the basic differences between the two. They also acknowledged that genetically engineered algae might be equipped with so-called “suicide genes” that would make it impossible for the algae to survive a release into the wild.
“If such precautions are taken in lieu of thorough environmental assessments, more information should be required to ensure their long-term success and to prevent (genetically engineered) algae from evolving to silence or overcome biological traits that are designed to kill them,” the authors wrote.
Snow also noted that before genetically engineered crop plants can be commercialized, they are grown in various outdoor environments to test their endurance under different conditions. The permitting process for these plots helps inform the government and the public about these agricultural efforts. Even if the exact genes used to engineer these crops are protected as proprietary information, the species and new traits they carry are made public.
“With algae, this can all happen in a greenhouse because they’re so small. That means they’re not really accessible for scientists to find out what companies are working with, and it’s going to be like that until very late in the process,” Snow said.
And to be clear, Snow said she and Smith are not looking to hinder these efforts.
“We’re trying to be constructive and get the word out, to get the conversation going,” she said.Contact: Allison Snow, (614) 292-3445; Snow.email@example.com
Emily Caldwell | Newswise Science News
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences | <urn:uuid:4bdda441-6b4e-441d-92a4-7ca7e3a70856> | 3.625 | 1,657 | Content Listing | Science & Tech. | 36.62963 | 95,489,861 |
lub: information operators: least upper bound (lub) and greatest lower bound (glb)
Lub is an experiment in computing least upper information bounds on
(partially defined) functional values. It provides a
that is consistent with the
unamb operator but has a more liberal
unamb requires its arguments to equal when
neither is bottom,
lub is able to synthesize a value from the
partial information contained in both of its arguments.
This module also defines
glb, which intersects information.
Project wiki page: http://haskell.org/haskellwiki/lub
© 2008 by Conal Elliott; BSD3 license.
|Versions||0.0.0, 0.0.1, 0.0.2, 0.0.3, 0.0.4, 0.0.5, 0.0.6, 0.1.1, 0.1.2, 0.1.3, 0.1.5, 0.1.6, 0.1.7|
|Dependencies||base (<5), unamb (>=0.2.4) [details]|
|Copyright||(c) 2008,2009,2010 by Conal Elliott|
|Category||Concurrency, Data, Other|
|Uploaded||by ConalElliott at Mon Feb 6 00:44:02 UTC 2012|
|Downloads||4574 total (16 in the last 30 days)|
|Rating||(no votes yet) [estimated by rule of succession]|
|Status||Docs uploaded by user
Build status unknown [no reports yet]
Hackage Matrix CI
For package maintainers and hackage trustees | <urn:uuid:18b59e91-6b52-4c64-8a8f-5dfaeba98780> | 2.578125 | 365 | Documentation | Software Dev. | 87.010936 | 95,489,867 |
This visualisation of temperatures in Lancashire (UK) shows annual mean data from 1754-2015. The long-term warming trend is clear, with variability from year to year, and some temporary cooler periods due to large volcanic eruptions. The average of the 19th century (black line) separates the warm and cold colours. Continue reading Lancashire temperatures, visualised→
If you watched the opening ceremony of the Olympics, you would have noticed a segment discussing climate change, accompanied by graphics of CO2 emissions, Arctic sea ice melting, sea level rise and a somewhat familiar spiral representation of rising global temperatures (above), a version of which you may have seen somewhere before.
The Earth hasn’t always been struggling with global warming. Around 34 million years ago at the Eocene-Oligocene Transition (EOT) the Earth was undergoing a period of global cooling. This significant shift in climate led to the formation of the first permanent ice sheets of the Cenozoic Era over Antarctica, as shown by the dramatic shift (in a geologic sense) in the oxygen isotope records . The cooling, likely a result of declining atmospheric carbon dioxide levels but potentially also coinciding with Southern Ocean gateway changes, turned Antarctica from a green forested continent to the land of ice we know today. This is illustrated with an image of how this world might have looked. | <urn:uuid:cfa7dd1e-bf1e-4ae3-8105-9da877363a9e> | 3.578125 | 280 | Knowledge Article | Science & Tech. | 25.55509 | 95,489,890 |
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The United States is currently in the midst of wildfire season, with 1,218 wildfires burning more than 340,000 acres of national forests in California alone.
Wildfires can be destructive and catastrophic for natural habitats and the firefighters tasked with containing them. However, they can also have surprising and beneficial aspects in several areas. Here are five surprising facts you may not know about “Nature’s Housekeepers.”
Contrary to popular belief, the wildfires themselves are not devastating to all animals. Large mammals usually do not die within the fire; their instincts will lead them to depart their habitat before they are threatened.
For example, during the devastating 1998 Yosemite wildfire, only 1 percent of the native elk population was killed in the blaze. “Wildland Fire in Ecosystems: Effect of Fire on Fauna,” a 2000 study by the United States Department of Agriculture and Forest Service, notes that “Despite the perception by the general public that wildland fire is devastating to animals, fires generally kill and injure a relatively small proportion of animal populations.”
The animals who suffer the most population loss are less mobile animals like small rodents and insects.
However, wildfires can still pose dangers to wildlife even after the blaze has been extinguished. Many animals can die from smoke inhalation. Other populations can also face difficulty with the destruction of their natural habitat for food sources and landscape.
These “fire tornadoes” are most often referred to as fire whirls. They are a rare but destructive aspect to wildfires and can be responsible for the rapid spread of fires that were on track to be contained. Meteorologically, they are most related to dust devils or whirlwinds.
NOAA has defined a fire whirl as a “vigorous atmospheric circulation, created when highly unstable, superheated, dry air near the ground breaks through the boundary layer and shoots upward in a swirling motion.”
The scope of these fire events can range from 100 to 1,000 feet and contain rotational velocities of up to 90 mph. When encountered, they cause extreme problems for firefighters because their direction and speed are almost impossible to predict.
A study published in Ecosphere named “Climate Change and Disruptions to Global Fire Activity” deduced that “warmer and drier weather may increase fire activity in biomass-rich areas [such as forests, grasslands], but have the opposite effect in moisture-stressed biomes [ice caps, deserts].”
While the effects of climate change on wildfires varies based on the environment and location, the authors predicted that higher northern latitudes, including the western United States, would experience a pronounced increase in fires.
This study did not factor in man-made wildfires but forecast the confluence of temperature, biomass and annual precipitation to determine their findings.
The beetle of the subgenus Melanophils uses its specialized infrared radiation sensors to detect burning forests. Once they have found their desired inferno, they mate and lay eggs in the scorched trees. The beetles find wildfire-ravaged landscapes desirable because the dead trees no longer have defense mechanisms like sap to protect insects from burrowing.
The U.S. Department of Defense has studied the beetles’ infrared sensing capabilities in the hopes it could help defense technology, such as heat-seeking missiles.
While fires may be caused by lightning strikes and other naturally occurring events, it is estimated that over 80 percent of wildfires are direct results of human error. Unattended campfires and discarded cigarettes are a few of the common man-made causes and they can destroy thousands of acres and endanger millions of lives.
Always practice fire safety and remember, as Smokey the Bear says, “Only you can prevent wildfires.”
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
Deadly heat will continue across Japan through at least Thursday, following the hottest day on record in Japan.
Mars has been growing bigger and brighter in the night sky in 2018 and it will reach its peak on Thursday night, bringing the best opportunity to view the Red Planet since 2003.
A switch to a cooler weather pattern in the midwestern United States will come at the expense of violent thunderstorms prior to the middle of the week.
The intense record heat baking the south-central United States is expected to get trimmed back early this week, but a sweep of refreshing air is not on the horizon.
This past weekend's rainstorm was only the start of an abnormally wet pattern that will elevate the flood risk in the eastern United States into the end of the month.
Despite NASCAR moving up the start time of the Foxwoods Resort Casino 301, rain has hung on and delayed the race at Loudon, New Hampshire.
Yet another round of severe weather is threatening the southeastern United States to close out this weekend. | <urn:uuid:697f411d-dfed-4b71-a146-4e54f74dee1c> | 4.03125 | 1,020 | Listicle | Science & Tech. | 33.966925 | 95,489,895 |
Earth came early to the party in the evolving universe. According to a new theoretical study, when our solar system was born 4.6 billion years ago only eight percent of the potentially habitable planets that will ever form in the universe existed. And, the party won't be over when the sun burns out in another 6 billion years. The bulk of those planets -- 92 percent -- have yet to be born.
This conclusion is based on an assessment of data collected by NASA's Hubble Space Telescope and the prolific planet-hunting Kepler space observatory.
"Our main motivation was understanding the Earth's place in the context of the rest of the universe," said study author Peter Behroozi of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, "Compared to all the planets that will ever form in the universe, the Earth is actually quite early."
Looking far away and far back in time, Hubble has given astronomers a "family album" of galaxy observations that chronicle the universe's star formation history as galaxies grew. The data show that the universe was making stars at a fast rate 10 billion years ago, but the fraction of the universe's hydrogen and helium gas that was involved was very low.
Today, star birth is happening at a much slower rate than long ago, but there is so much leftover gas available that the universe will keep cooking up stars and planets for a very long time to come.
"There is enough remaining material [after the big bang] to produce even more planets in the future, in the Milky Way and beyond," added co-investigator Molly Peeples of STScI.
Kepler's planet survey indicates that Earth-sized planets in a star's habitable zone, the perfect distance that could allow water to pool on the surface, are ubiquitous in our galaxy. Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe.
This leaves plenty of opportunity for untold more Earth-sized planets in the habitable zone to arise in the future. The last star isn't expected to burn out until 100 trillion years from now. That's plenty of time for literally anything to happen on the planet landscape.
The researchers say that future Earths are more likely to appear inside giant galaxy clusters and also in dwarf galaxies, which have yet to use up all their gas for building stars and accompanying planetary systems. By contrast, our Milky Way galaxy has used up much more of the gas available for future star formation.
A big advantage to our civilization arising early in the evolution of the universe is our being able to use powerful telescopes like Hubble to trace our lineage from the big bang through the early evolution of galaxies. The observational evidence for the big bang and cosmic evolution, encoded in light and other electromagnetic radiation, will be all but erased away 1 trillion years from now due to the runaway expansion of space. Any far-future civilizations that might arise will be largely clueless as to how or if the universe began and evolved.
The results will appear in the Oct. 20 Monthly Notices of the Royal Astronomical Society.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington.
For images and more information visit:
Ray Villard | EurekAlert!
What happens when we heat the atomic lattice of a magnet all of a sudden?
17.07.2018 | Forschungsverbund Berlin
Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
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17.07.2018 | Power and Electrical Engineering | <urn:uuid:1f0c44ac-7e58-41bc-b7fe-967c6afb9ec2> | 3.78125 | 1,390 | Content Listing | Science & Tech. | 40.348507 | 95,489,922 |
Tehran, the capital of the Islamic Republic of Iran (IRI), is located in the north of the country with a population of about 8.5 million. The population can reach over 12.5 million during the day, with people from nearby cities commuting daily to Tehran for work.
Groundwater potential analysis prepares better comprehension of hydrological settings of different regions. This study shows the potency of two GIS-based data driven bivariate techniques namely statistical index (SI) and Dempster–Shafer theory (DST) to analyze groundwater potential in Broujerd region of Iran. The research was done using 11 groundwater conditioning factors and 496 spring positions. | <urn:uuid:024a5d21-18a8-4adb-9ef0-55b0d2996e44> | 2.546875 | 137 | Knowledge Article | Science & Tech. | 38.010769 | 95,489,939 |
Oak Ridge National Laboratory’s Environmental Sciences Division’s Madhavi Martin has reinvented an old analytical method, finding some very new applications for the technology in the process. She uses laser-induced breakdown spectroscopy—a technique invented in the 1960s—to collect elemental fingerprints.
The LIBS method uses a focused laser to evaporate sample materials, breaking down all of the bonds and producing optical emissions of very specific wavelengths depending on the elements present within the sample.
“The wavelength emissions are the fingerprints of the elements in the sample,” Madhavi says. “One advantage of the method is that I can analyze any kind of sample: liquid, solid, gas or aerosol.”
One of her collaborators at the Lab has continued to test the claim that her method can work with any kind of sample. Arpad Vass approached her about five years ago, asking if the method she had been using to analyze wood chemistry could be applied to bone.
“My first reaction was, ‘Ewww, bone?’ My second reaction was, ‘Let’s try it,’” says Madhavi.
After looking at the first few bone samples, she realized that she could see clear differences between them.
Her method can even determine whether you took your multivitamins or not.
“We need more bones in the experimental data set before the method is ready to be used for biological profiling, but the results are promising,” Madhavi says, pointing out the peaks in the spectrum that tell her the bone sample is probably from a woman who took her daily supplements.
The same method can be used to differentiate between human and animal bones.
“Sometimes people find a fragment of bone in the backyard, and this method can quickly determine whether it is human or not,” says Madhavi, explaining that the wait for DNA sequencing may be as long as a month and could be inconclusive for old bones. The method could also be used to analyze bones that have been exposed to conditions that degrade DNA, like high heat or the passage of time.
Her work has even helped to solve a murder, connecting a suspect to the victim by showing that firewood at the scene of the crime was from the same tree that the suspect later took to a bonfire and burned at his own home.
Early one morning, she got a call from Henri Grissino-Mayer, an expert in tree-ring analysis in the University of Tennessee’s geography department, who had been called in to consult on the case. Unfortunately for Grissino-Mayer, the firewood turned out to be from a mesquite tree—one of the worst for analyzing tree rings because of its erratic growth patterns.
“He called and asked if I could test some logs for him, but he didn’t mention anything about a murder,” says Madhavi. “When I finished testing all 14 of the logs, I was very disappointed because they all looked the same except for one.” She called Grissino-Mayer back with the results and he immediately asked which one was different—it was the control, a piece of firewood that wasn’t from the case in question.
“He was very excited; I was very surprised when I found out,” Madhavi says. “The data that I thought was so uninteresting turned out to be very important—the elemental fingerprint of the logs was the same, tying the suspect to the scene.”
Madhavi is also using the technique to improve phytoremediation of large-scale polluted areas.
The use of plants to clean up environments that have high levels of pollutants such as mercury or TNT shows much promise. Some plants take up and sequester the pollutants better than others. Using her method, Madhavi says that she can monitor the amount of pollutants present in prospective plants, helping to choose the best candidate for phytoremediation efforts.
“It’s been exciting because the tools that we have now—better lasers, better instruments for detection—have revived the LIBS technology,” she says.
People are using LIBS to look at all kinds of materials, but Madhavi is one of the few using it for environmental analysis.
Like this article? Click here to subscribe to free newsletters from Lab Manager | <urn:uuid:2e57c4a7-583e-4195-aca9-af5c29f1331e> | 3.171875 | 917 | News Article | Science & Tech. | 41.0477 | 95,489,954 |
Throughout the past three decades, plant physiologists have repeatedly proposed that plants conducting nitrogen assimilation in aboveground tissue should require less photosynthate per unit N assimilated than those that conduct N-assimilation in their roots. A review of research on agricultural and transgenic plants reveals that the Leaf:Root (L:R) partitioning of one enzyme in particular, glutamine synthetase (GS, E.C. 184.108.40.206) has a greater effect on
stress tolerance and growth rate than the other enzymes of N metabolism. The rate limiting enzyme in N-assimilation, GS catalyzes the assimilation of ammonium to glutamine, producing the first organic molecule in the N-assimilation pathway. While not universally accepted, studies in agricultural and model plants have generated strong evidence supporting the advantages of a high L:R GS ratio, yet the ecological implications remain unexplored. In this thesis, I explore GS partitioning in two genera of salt marsh grasses through field and growth chamber studies. The first studies are on congeneric Spartina alterniflora and S. patens that exist adjacently in the salt marsh, along the natural stress gradients of salinity and waterlogging. I correctly hypothesized that the faster growing, more stress tolerant S. alterniflora would have a higher L:R GS activity ratio than S. patens and that the L:R GS activity in both species would be altered by N-source. To corroborate these findings, I investigated GS partitioning in native and invasive subspecies of Phragmites australis, finding that the invasive subspecies appears to maintain a higher L:R
GS activity than the less stress tolerant, slower growing native subspecies. I discuss my findings in both the Spartina spp. and P. australis ssp. from an ecological perspective. | <urn:uuid:00fceaf6-0577-41fd-929d-fa636a7b3612> | 2.578125 | 384 | Academic Writing | Science & Tech. | 37.22336 | 95,489,957 |
(Bloomberg) -- Getting ready to watch the solar eclipse? Bring a sweater along with those special glasses because the mercury could dip as the moon’s shadow crosses the land.
Millions of Americans across a 70-mile-wide (113-kilometer) corridor from Oregon to South Carolina will see the sky darken as the sun disappears from view, albeit for only a few minutes at a time.
Temperatures in those areas could tumble by as much as 10 degrees Fahrenheit (5.6 Celsius), according to Paul Walker, a meteorologist with AccuWeather Inc. in State College, Pennsylvania. Other parts of the nation will only experience a partial eclipse.
“That is assuming a totally sunny sky,” Walker said by telephone. “We will see a temperature drop where totality happens,” he said, referring to the path the eclipse will take across the U.S. where the sun will be completely blocked out.
The eclipse will disrupt the sun’s power to heat the ground, warm the atmosphere and supply electricity. It could also be ruined by a rainy day, patch of fog or even just a sudden thunderstorm in the wrong place. Given the limits of modern-day forecasting, predicting any one of those days in advance for an event that only lasts minutes is near impossible.
“It’s a difficult forecast challenge,” said Bob Henson, a meteorologist at Weather Underground in Boulder, Colorado. “You’re not forecasting a day’s weather, but for two minutes.”
The chill in the air will peak about five to 20 minutes after the moon’s shadow passes by. Temperatures could take three hours to rebound across the Great Plains and East Coast, said Brad Harvey, meteorologist with MDA Weather Services in Gaithersburg, Maryland.
“The change in temperature may be larger and take longer to recover in the West,” Harvey said. The eclipse will start to be seen in the morning which is “the time of day when temperatures are rising most rapidly.”
On the West Coast, the eclipse is due to start a little after 9 a.m. local time and peak about 10:15 a.m. In the central U.S., that will happen at 1:18 p.m. in St. Louis. The East Coast will see the biggest effect after 2:30 p.m.
As many as 12,000 megawatts of solar power will vanish along the path of the moon’s shadow along with the decrease in temperatures. Natural gas generators as well as hydroelectric plants and other sources will help fill in the gaps.
There will be little impact on winds, according to Harvey. “Gusts may be reduced because of stabilization of the air,” he said. The effect could be similar to a sea breeze, said Henson.
One of the odd things that could happen on a micro-scale is for fog to occur as sunshine fades and temperatures drop.
That the path of totality crosses three distinct weather zones also has to be factored in by meteorologists.
One is the Pacific Northwest, which is often clear and sunny at this time of year, except along the coast, Henson said. So people living inland will likely have a good chance of seeing the eclipse.
Smoke from wildfires could threaten to obscure the celestial event, said Frank Pereira, a forecaster at the U.S. Weather Prediction Center in College Park, Maryland. “In terms of cloud cover, it will be minimal across a good portion of that area.”
Showers and thunderstorms forecast to cross the region from Nebraska to Missouri Sunday night could linger into Monday, Pereira said. Southern Illinois, Kentucky and Tennessee should all have good weather.
Finally, east of the Mississippi, the typical summertime pattern can be one of afternoon thunderstorms that are difficult to forecast in advance and could make viewing the eclipse that much harder.
“If they pop up over you, you aren’t going to see it,” Henson said.
And it that happens? Well, North America gets another crack at a total solar eclipse in April 2024. | <urn:uuid:7f27b319-7460-4736-8792-2b9a5dfe7ae7> | 2.78125 | 871 | News Article | Science & Tech. | 60.328943 | 95,489,984 |
Species Detail - Common Cord-grass (Spartina anglica) - Species information displayed is based on all datasets.
Terrestrial Map - 10kmDistribution of the number of records recorded within each 10km grid square (ITM).
Marine Map - 50kmDistribution of the number of records recorded within each 50km grid square (WGS84).
Spartina townsendii auct., non H. Groves & J. Groves, Spartina x townsendii var. anglica
Invasive Species: Invasive Species || Invasive Species: Invasive Species >> High Impact Invasive Species || Invasive Species: Invasive Species >> Regulation S.I. 477 (Ireland)
29 January (recorded in 2006)
18 November (recorded in 2007)
National Biodiversity Data Centre, Ireland, Common Cord-grass (Spartina anglica), accessed 23 July 2018, <https://maps.biodiversityireland.ie/Species/45406> | <urn:uuid:c16a8ce1-1a73-4f9b-a0af-0e1dbff1bff9> | 2.734375 | 212 | Structured Data | Science & Tech. | 34.562594 | 95,490,011 |
See explanation below.
Work Step by Step
At anode, oxidation occurs so electrons flow from anode to cathode where reduction occurs. So we can say that irrespective of the cell type, electrons always flow from anode to cathode.
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After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback. | <urn:uuid:28b01e9e-1a06-4f34-8968-4c05f3229553> | 3 | 103 | Tutorial | Science & Tech. | 51.619431 | 95,490,035 |
doi:10.1038/nindia.2018.75 Published online 17 June 2018
Researchers at the Indian Institute of Science Education and Research (IISER) in Pune have developed the chemistry for creation of a rechargeable "green" battery based on hydrogen (H2), widely regarded as the cleanest chemical energy carrier and one of the most abundant elements available in nature.
Musthafa Ottakam Thotiyl and his team took an unusual route to overcome drawbacks such as poor availability, lack of safety, high costs, and environmental incompatibility faced by traditional metal ion batteries. Thotiyl and colleagues Neethu Dargily and Ravikumar Thimmappa have formulated, for the first time, a rechargeable battery chemistry based on hydrogen.
To do this, they substituted the platinum cathode of traditional batteries with a hydrogen storage molecule (quinone) which can capture oxidized hydrogen (or protons) generated at the anode. Since this molecule has the unique ability to both store and release hydrogen in a reversible manner, the device can be recharged multiple times, regenerating the original quinone molecules and hydrogen fuel back at the anode. "This leads to an electrically rechargeable battery based on a virtually non-polluting molecular fuel," the authors report. "Most importantly, we do not need to carry hydrogen all the time with us as we can recharge the device whenever required."
Hydrogen is widely used as fuel in energy conversion devices such as proton exchange membrane fuel cells. These fuel cells generate electricity by the oxidation of hydrogen at the platinum anode and reduction of oxygen (O2) at the platinum cathode. But H2-O2 fuel cells are non-rechargeable and can generate electricity only as long as hydrogen and oxygen are supplied to the system. In other words, one must carry hydrogen to use this device continuously.
The promise of the H2-O2 fuel cell technology has been further thwarted by issues of safety and storage of hydrogen and the necessity of heavy loading of expensive platinum catalysts especially for the oxygen reduction reaction.
Armed with the new chemistry, the IISER team is now making a solid state hydrogen ion battery to provide a green alternative to existing batteries. | <urn:uuid:09d0cc77-f0f0-4752-b18d-943d111269db> | 3.734375 | 460 | Truncated | Science & Tech. | 17.537668 | 95,490,076 |
Giant Tortoises Gain a Foothold on a Galapagos Island
Ecosystem needs further repair
A population of endangered giant tortoises, which once dwindled to just over a dozen, has recovered on the Galapagos island of Española, a finding described as "a true story of success and hope in conservation" by the ESF professor who is the lead author of a study published today (Oct. 28).
Some 40 years after the first captive-bred tortoises were reintroduced to the island by the Galapagos National Park Service, the endemic Española giant tortoises are reproducing and restoring some of the ecological damage caused by feral goats that were brought to the island in the late 19th century.
"The global population was down to just 15 tortoises by the 1960s. Now there are some 1,000 tortoises breeding on their own. The population is secure. It's a rare example of how biologists and managers can collaborate to recover a species from the brink of extinction, " said James P. Gibbs, a professor of vertebrate conservation biology at ESF and lead author of the paper published in the journal "PLOS ONE."
Gibbs and his collaborators assessed the tortoise population using 40 years of data from tortoises marked and recaptured repeatedly for measurement and monitoring by members of the Galapagos National Park Service, Charles Darwin Foundation, and visiting scientists.
But there is another side to the success story: while the tortoise population is stable, it is not likely to increase until more of the landscape recovers from the damage inflicted by the now-eradicated goats.
"Population restoration is one thing but ecological restoration is going to take a lot longer," he said.
After the goats devoured all the grassy vegetation and were subsequently removed from the island, more shrubs and small trees have grown on Española. This hinders both the growth of cactus, which is a vital piece of a tortoise's diet, and the tortoises' movement. Chemical analysis of the soil, done by Dr. Mark Teece, an ESF chemistry professor, shows there has been a pronounced shift from grasses to woody plants on the island in the last 100 years.
The shrubs and trees also inhibit the movements of the endangered waved albatross that breeds on the island. Gibbs said the plants make it difficult for the ungainly sea birds to take flight.
"This is a miraculous conservation success accomplished by the Galapagos National Park Service," said Gibbs, " but there is yet more work to fully recover the ecosystem upon which the tortoises and other rare species depend."
Gibbs' co-authors on the study are Elizabeth A. Hunter, an ESF alumna who is now a Ph.D. student at the University of Georgia; Kevin T. Shoemaker, an ESF alumnus who is now a research scientist at SUNY's Stony Brook University; Washington H. Tapia formerly of the Galapagos National Park Service; and Linda J. Cayot of the Galapagos Conservancy. The research was supported by the Galapagos National Park Service, the Galapagos Conservancy, the Prometeo Program of Ecuador's National Secretariat for Higher Education, Science, Technology and Innovation, and the U.S. National Science Foundation.
Recent ESF News
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Most Precise Test of Einstein’s General Relativity Outside Milky Way
Astronomers using the VLT in Chile, and the NASA/ESA Hubble Space Telescope, have made the most precise test yet of Einstein’s general theory of relativity outside the Milky Way. The nearby galaxy ESO 325-G004 acts as a strong gravitational lens, distorting light from a distant galaxy behind it to create an Einstein ring around its centre. By comparing the mass of ESO 325-G004 with the curvature of space around it, the astronomers found that gravity on these astronomical length-scales behaves as predicted by general relativity. This rules out some alternative theories of gravity.
Carbon Rich Asteroid in Kuiper Belt
ESO astronomers have investigated a relic of the primordial Solar System. The unusual Kuiper Belt Object 2004 EW95 is a carbon-rich asteroid, the first of its kind to be confirmed in the cold outer reaches of the Solar System. It has most likely formed in the asteroid belt between Mars and Jupiter and later flung billions of kilometres from its origin to its current home in the Kuiper Belt
Dead Star Circled by Light
Spectacular new pictures, created from images from both ground- and space-based telescopes, tell the story of the hunt for an elusive missing object hidden amid a complex tangle of gaseous filaments in the Small Magellanic Cloud, about 200 000 light-years from Earth.
Closest Temperate World Orbiting Quiet Star Discovered
A temperate Earth-sized planet has been discovered only 11 light-years from Earth using ESO’s unique planet-hunting HARPS instrument. The new world has been designated Ross 128b and is now the second closest temperate planet so far detected after Proxima b. It is also the closest planet to be discovered orbiting an inactive red dwarf star, which may increase the likelihood that this planet could potentially sustain life. Ross 128 b will be a prime target for ESO’s Extremely Large Telescope, which will be able to search for biomarkers in the planet's atmosphere.
Best Ever Image of a Star’s Surface and Atmosphere
Quite amazing is the new VLT Interferometer imager where astronomers have constructed the most detailed picture ever of a star, the red supergiant Antares. They have also made the first map of the velocities of material in the atmosphere of a star other than the Sun, revealing unexpected turbulence in Antares’s huge extended atmosphere.
Dazzling Spiral with an Active Heart
Magnificent face-on view of the barred spiral galaxy Messier 77. The image does justice to the galaxy’s beauty, showcasing its glittering arms criss-crossed with dust lanes.This impressive luminosity is caused by intense radiation blasting out from a central engine — the accretion disc surrounding a super massive black hole. Material that falls towards the black hole is compressed and heated up to incredible temperatures, causing it to radiate a tremendous amount of energy. | <urn:uuid:cf3984fa-61cd-4f38-8242-596f9af32871> | 2.796875 | 624 | Content Listing | Science & Tech. | 29.680904 | 95,490,163 |
Name ____________________________ Date _________________ Block____________ Physics Wave Equation Worksheet Use the equations in the box to the right to solve the following problems. 1. The period of a wave is 5 s. Calculate its frequency. (Answer: 0.2 Hz) Equations f= 1 T f = frequency T = period T= 1 f v = λf v = speed λ = wavelength v= λ T 2. The period of a wave is 4 s. Calculate its frequency. (Answer: 0.25 Hz) 3. One cycle of a wave is 1.3 s long. What is its frequency? (Answer: 0.77 Hz) 4. The frequency of a wave is 7 Hz. Find the period of the wave. (Answer: 0.14 s) 5. The frequency of a wave is 0.4 Hz. Calculate the period. (Answer: 2.5 s) 6. If the wavelength of a wave is 3 m and its frequency is 6 Hz, what is the speed of the wave? (Answer: 18 m/s) 7. An ocean wave is about 15 m long. Its period is 18 s. a. Find the frequency of the wave. (Answer: 0.056 Hz) b. Find the speed of the wave. (Answer: 0.83 m/s) 8. As I was sitting on a dock, I noticed that the wavelength of the waves were about 6 m long. The crest of each wave would pass the front of the dock every 8 s. a. Find the frequency of the wave. (Answer: 0.125 Hz) b. Find the speed of the wave. (Answer: 0.75 m/s) 9. A wave is traveling at the speed of light, 3 x 108 m/s. If it has a frequency of 4 x 1015 Hz, what is its wavelength? (Answer: 7.5 x 10-8 m) 10. What is the only way to change the speed of a wave? 11. If the speed of a wave stays constant, but the wavelength is increased, what happens to the frequency? | <urn:uuid:e8de7aa5-8e9c-4b41-ac78-ae2411c11923> | 4.15625 | 442 | Content Listing | Science & Tech. | 113.210957 | 95,490,168 |