UAL939 United
LHR → SFO
· 2:24Quality 94side-on
Software-steadied: the hops of the camera motor are smoothed out (plane wobble −79%). Download
Trace
Where the aircraft sat in the frame, second by second. Click the chart to jump the video there.
—FOV —az —el —pose —
Loading telemetry…
Lock
Events
Tracking metrics
How well the camera kept the aircraft centred. Tap a metric for what it means and what good looks like.
- Lockshare of the pass
- 96%
- First lockfrom target selected
- 5.2 s
- Centring, medianaz / el while locked
- 0.12° / 0.12°
- Centring, 90th pctaz / el while locked
- 0.36° / 0.33°
- Tightest field of viewhorizontal
- 3.4°
- Time to 8°from first lock
- 5.3 s
- Time to tightestfrom first lock
- 12.5 s
- Time at telefield of view ≤ 5.5°
- 114.2 s
- Jitter at teleaz / el, standard deviation
- 0.14° / 0.16°
- Swing at teleaz / el, peak to peak
- 0.96° / 1.33°
- Pan reversalsper 10 s at tele
- 0.0
- Largest pan hopin any 1 s at tele
- 4.49°
- Largest tilt hopin any 1 s at tele
- 1.80°
- Pose error, mediancommand vs camera
- 0.69°
- Largest correctionvision vs prediction
- 1.96°
- Zoom steps
- 38
Aircraft & route
- Flight
- UAL939
- Registration
- —
- Type
- —
- Airline
- United
- From
- LHR · London
- To
- SFO · San Francisco
- Ground speed
- 260 kt
- Altitude at closest
- 11,500 ft
- Vertical rate
- -64 ft/min
- Category
- A5
- ICAO hex
- ab0faa
Pass geometry
- Max elevation
- 70.3°
- Elevation at start → end
- 17.8° → 21.6°
- Azimuth at start → end
- 326° NNW → 137° SE
- Closest-approach azimuth
- 50° NE
- Minimum slant range
- 3.7 km
- Heading at closest
- 140° SE
- Aspect at closest
- side-on (90°)
- Turn
- straight (14°)
- Departure
- No
- Zenith pass
- No
- Dead-zone wrap
- No
- Duration
- 2:24 (143.6 s)
- Lock
- 96%
Build & tuning
The tracker build that flew this pass and the live settings that mattered, so passes can be compared across changes.
- Build
- 2026-10-16i — lock-first on; shadow silhouette sky-masked
- Commit
- 5610684
- Node
- v22.22.2
- Camera
- TONGVEO 20x PTZ · 1920×1080 @ 30 fps
- Clip
- 20.5 MB · 144.0 s · offset -1.6 s
- pursuit
- velocity
- maxLeadSec
- 3
- panLatencySec
- 0.6
- tiltLatencySec
- 0.4
- rippleDeg
- 0.5
- rippleTeleDeg
- 0.25
- maxSpeedStepFwps
- 0.45
- speedReachFrac
- 0.8
- lockedSigmaDeg
- 0.35
- sigmaGrowthDps
- 0.1
- aimLeadSec
- -0.24
- correctionSlewDps
- 2.5
- kp
- 1
- ki
- 0.6
This clip and poster are © Skylight (Cameron Paczek): free for non-commercial use with credit to skylightceiling.com, not MIT. License