Update observatory database: 609 observatories

README.md

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+---
+license: cc0-1.0
+pretty_name: "Observatory Database"
+language:
+  - en
+description: >-
+  Comprehensive database of astronomical observatories worldwide, sourced from Wikidata.
+  609 observatories from 59 countries with coordinates, elevation,
+  aperture size, operator, and wavelength coverage.
+size_categories:
+  - n<1K
+task_categories:
+  - tabular-classification
+tags:
+  - space
+  - astronomy
+  - observatories
+  - telescopes
+  - wikidata
+  - open-data
+  - tabular-data
+  - parquet
+configs:
+  - config_name: default
+    data_files:
+      - split: train
+        path: data/observatories.parquet
+---
+
+# Observatory Database
+
+*Part of the [Astronomy Datasets](https://huggingface.co/collections/juliensimon/astronomy-datasets-69c24caf2f17e36128946743) collection on Hugging Face.*
+
+Comprehensive database of astronomical observatories — **609** facilities from
+**59** countries, sourced from [Wikidata](https://www.wikidata.org/).
+
+## Dataset description
+
+From ancient naked-eye platforms to modern space-based flagship missions, observatories
+have been humanity's primary windows into the universe. This dataset covers optical
+telescopes, radio dishes, neutrino detectors, gamma-ray satellites, and space observatories —
+any facility classified in Wikidata as an astronomical observatory (Q62832), space
+observatory (Q1377879), or radio observatory (Q148578).
+
+Each entry includes geographic coordinates (latitude/longitude), elevation above sea level,
+primary aperture size, operating organization, opening date, and the electromagnetic
+wavelength bands observed. This enables spatial analysis of observatory distribution,
+historical studies of observational astronomy, and comparison of ground-based vs.
+space-based capabilities.
+
+Sourced from Wikidata's structured knowledge base, curated by the WikiProject Astronomy
+community with contributions from professional astronomers and enthusiasts worldwide.
+
+## Schema
+
+| Column | Type | Description |
+|--------|------|-------------|
+| `wikidata_id` | string | Wikidata entity ID (e.g. Q179224) |
+| `name` | string | Observatory name |
+| `country` | string | Country where the observatory is located |
+| `latitude` | float | Geographic latitude (decimal degrees) |
+| `longitude` | float | Geographic longitude (decimal degrees) |
+| `elevation_m` | float | Elevation above sea level (metres) |
+| `aperture_m` | float | Primary mirror/dish aperture (metres) |
+| `operator` | string | Operating organization or agency |
+| `opening_date` | string | Date the observatory opened (YYYY-MM-DD) |
+| `wavelengths` | string | Observed wavelength bands, semicolon-separated |
+
+## Quick stats
+
+- **609** observatories from **59** countries
+- **357** with geographic coordinates
+- **0** with aperture data
+- **46** with elevation data
+- Highest elevation: Caltech Submillimeter Observatory (13,570 m)
+- Estimated ground-based: **510**, space-based: **99**
+- Top countries: United States (109), United Kingdom (43), Italy (25), France (24), Netherlands (19)
+- Top wavelength bands: 
+
+## Usage
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("juliensimon/observatory-database", split="train")
+df = ds.to_pandas()
+
+# Observatories by country
+print(df["country"].value_counts().head(10))
+
+# High-altitude observatories (above 3000 m)
+high_alt = df[df["elevation_m"] > 3000].sort_values("elevation_m", ascending=False)
+print(high_alt[["name", "country", "elevation_m"]].head(10))
+
+# Large aperture telescopes (> 8 m)
+large = df[df["aperture_m"] > 8].sort_values("aperture_m", ascending=False)
+print(large[["name", "country", "aperture_m"]])
+
+# Radio observatories
+radio = df[df["wavelengths"].str.contains("radio", case=False, na=False)]
+print(f"{len(radio):,} radio observatories")
+
+# Space observatories
+space_obs = df[df["wavelengths"].str.contains("X-ray|gamma|ultraviolet", case=False, na=False)]
+print(space_obs[["name", "wavelengths"]].head(10))
+```
+
+## Data source
+
+[Wikidata](https://www.wikidata.org/) SPARQL endpoint. Observatories identified via
+property P31 (instance of) = Q62832 (astronomical observatory), Q1377879 (space
+observatory), or Q148578 (radio observatory). Data is community-curated by
+[WikiProject Astronomy](https://www.wikidata.org/wiki/Wikidata:WikiProject_Astronomy).
+
+## Update schedule
+
+Quarterly (January, April, July, October). Re-run manually to pick up newly catalogued facilities.
+
+## Related datasets
+
+- [astronomer-database](https://huggingface.co/datasets/juliensimon/astronomer-database) — Astronomers from Wikidata
+- [chandra-sources](https://huggingface.co/datasets/juliensimon/chandra-sources) — Chandra X-ray source catalog
+
+## Pipeline
+
+Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)
+
+## Support
+
+If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/observatory-database) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.
+
+## Citation
+
+```bibtex
+@dataset{observatory_database,
+  author = {Simon, Julien},
+  title = {Observatory Database},
+  year = {2026},
+  publisher = {Hugging Face},
+  url = {https://huggingface.co/datasets/juliensimon/observatory-database},
+  note = {Sourced from Wikidata (CC0)}
+}
+```
+
+## License
+
+[CC0-1.0](https://creativecommons.org/publicdomain/zero/1.0/) (Wikidata content is public domain)

data/observatories.parquet

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