| --- |
| license: cc-by-4.0 |
| task_categories: |
| - object-detection |
| - audio-classification |
| tags: |
| - drone-detection |
| - counter-uas |
| - acoustic-array |
| - ptz-tracking |
| - multimodal |
| - gps-truth |
| - low-altitude |
| pretty_name: "nightjar field flight 2026-08-04 #3 — verification of the proportional zoom climb" |
| --- |
| |
| # nightjar flight — 2026-08-04, third sortie |
|
|
| Short verification sortie. Same rig and site as the other 2026-08-04 sessions. GPS truth: |
| **1,997 valid UTC stamps of 1,998**. |
|
|
| | | | |
| |---|---| |
| | airborne | 200 s | |
| | max height | 14 m | |
| | max slant range | 142 m | |
| | median elevation angle | **6°** | |
| | path flown | 357 m | |
|
|
| ## Why this session exists |
|
|
| It verifies a two-stage fix to the cued zoom climb. The cue's containment focal (~7.07 mm from |
| FOV ≥ 2·k·σ) had been computed on every cue and never commanded; when that was fixed, the |
| climb then ran at full lens speed into a 1 mm deadband and **overshot**. This session carries |
| the proportional-speed correction. Measured against the 7.07 mm ceiling: |
|
|
| | SEARCH focal | previous sortie | **this sortie** | |
| |---|---|---| |
| | median | 10.88 mm | **5.93 mm** | |
| | p90 | 11.80 mm | 10.92 mm | |
| | max | **20.03 mm** | **10.92 mm** | |
|
|
| The long overshoot tail is gone and the median now sits just under the ceiling instead of 54% |
| above it. Zoom also climbs on tracks properly here: TRACK median 2.37×, p90 9.90×, max 20.27×, |
| with 39.7% of the flight above 2× and 6.9% above 5×. |
|
|
| ## What this session does NOT show |
|
|
| ⚠ **At 14 m altitude and a 6° median elevation angle the drone was on the treeline**, against |
| foliage rather than sky, and never got past 142 m. Detection read 31% inside 50 m and 0% |
| beyond — same as every other sortie that day — and the tracked median range was 19 m. So this |
| data verifies camera *behaviour* only. It says nothing about the 50–150 m detection problem, |
| and it sits at the null of a horizontal array's elevation response (sensitivity goes as |
| sin(el)), so it is also a poor test of acoustic elevation. |
|
|
| ## Cue gate |
|
|
| 8 cue candidates, 3 chirp-rejects, **all 8 at the relaxed 10.0 dB threshold** — nightjar was |
| never in TRACK when a cue was evaluated. A state-dependent presence gate (14.6 dB while |
| tracking, 10.0 while searching) was live; `audio/cue_log.jsonl` now stamps `thr_db` and |
| `nj_state` on every candidate so each cue is attributable to the threshold that produced it. |
|
|
| ## Contents / gotchas |
|
|
| ``` |
| audio/uma16_<epoch>.wav UMA-16, 16 ch, S16_LE audio/sb_<epoch>.wav SB-POLARIS, 8 ch, S32_LE |
| audio/cue_log.jsonl cue gate log (thr_db, nj_state per candidate) |
| video_segments.tar 1080p native + 768x432 substream, 60 s MPEG-TS |
| blackbox/state.jsonl tracker FSM ~2.9 Hz blackbox/frames.tar substream stills f<epoch_ms>.jpg |
| dji/*.csv, *.txt decoded + original FlightRecord (CUSTOM.dateTime = true UTC) |
| ``` |
|
|
| UMA-16 0-based channel 9 is a dead electronic-floor channel — exclude it, run on 15. |
| SB-POLARIS has 3 live capsules of 8; detect them by RMS (live ~−70 dBFS, dead ~−190) rather |
| than hardcoding. ⚠ **The arrays use different sample widths** — UMA S16_LE, SB S32_LE; reading |
| both as int16 scrambles SB channel identity and destroys its spectrum. |
|
|
| Calibration as flown: `az_offset_deg` **301.37**, `invert_az` true (re-solved from the JBL |
| beacon that afternoon, 0.40° drift). Cue producer: cheap daemon (`SUBHUNT=0`). Site notch |
| 100–200 Hz. Start pose pan 178.9 / tilt 45, pointed at the JBL beacon. |
|
|
| ## Elevation datum (fit_el_datum, 2026-08-16) |
|
|
| The rig height in this day's drone-altitude frame (the missing constant that |
| floored close-range elevation truth at ~25 deg estate-wide) is SOLVED from |
| this repo's own blackbox TRACK/LOCK poses vs the eval-cache GPS — no |
| acoustics, no field survey. |
|
|
| - **z_rig = -0.20 m**, el = -1 x tilt + 87.43 deg |
| - north offset -115.59 deg (pan sign -1), az gate residual 1.5 deg |
| - med |el residual| **1.11 deg** over 71 camera-on-drone rows, horiz 19-30 m |
| - per band: 0-30m: 1.11 deg (n=71) |
| |
| Artifact: `joshruby/acoustic-knowledge` -> `v3/assets/el_datum/nightjar-flight-20260804-3.json`. |
| Tool: `sirch613/subhunt-v2` `v3/fit_el_datum.py`. Derive el truth as |
| atan2(hgt - z_rig, horiz) — NEVER from raw hgt. |
| |
