UAL939 United
LHR → SFO
· 0:52Quality 79side-on
Software-steadied: the hops of the camera motor are smoothed out (plane wobble −74%). 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
- 54%
- First lockfrom target selected
- 7.4 s
- Centring, medianaz / el while locked
- 0.27° / 0.17°
- Centring, 90th pctaz / el while locked
- 1.28° / 0.53°
- Tightest field of viewhorizontal
- 4.1°
- Time to 8°from first lock
- 8.6 s
- Time to tightestfrom first lock
- 21.3 s
- Time at telefield of view ≤ 5.5°
- 9.3 s
- Jitter at teleaz / el, standard deviation
- 0.21° / 0.15°
- Swing at teleaz / el, peak to peak
- 0.76° / 0.50°
- Pan reversalsper 10 s at tele
- 0.0
- Largest pan hopin any 1 s at tele
- 2.41°
- Largest tilt hopin any 1 s at tele
- 0.82°
- Pose error, mediancommand vs camera
- 0.73°
- Largest correctionvision vs prediction
- 1.77°
- Zoom steps
- 31
Aircraft & route
- Flight
- UAL939
- Registration
- —
- Type
- —
- Airline
- United
- From
- LHR · London
- To
- SFO · San Francisco
- Ground speed
- 297 kt
- Altitude at closest
- 11,225 ft
- Vertical rate
- —
- Category
- A5
- ICAO hex
- a9823d
Pass geometry
- Max elevation
- 28.8°
- Elevation at start → end
- 28.7° → 19.1°
- Azimuth at start → end
- 12° NNE → 66° ENE
- Closest-approach azimuth
- 16° NNE
- Minimum slant range
- 7.1 km
- Heading at closest
- 108° ESE
- Aspect at closest
- side-on (89°)
- Turn
- straight (0°)
- Departure
- No
- Zenith pass
- No
- Dead-zone wrap
- No
- Duration
- 0:52 (52.1 s)
- Lock
- 54%
Build & tuning
The tracker build that flew this pass and the live settings that mattered, so passes can be compared across changes.
- Build
- 2026-10-13k — centred plane + noisy motion check no longer demotes the zoom
- Commit
- 181d1fa+wip
- Node
- v22.22.2
- Camera
- TONGVEO 20x PTZ · 1920×1080 @ 30 fps
- Clip
- 26.0 MB · 52.0 s · offset -1.6 s
- pursuit
- velocity
- maxLeadSec
- 3
- panLatencySec
- 0.6
- tiltLatencySec
- 0.4
- rippleDeg
- 0.5
- rippleTeleDeg
- 0.25
- rateFloorDegPerDps
- 2.5
- rateFloorMaxDeg
- 12
- lockedSigmaDeg
- 0.35
- 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