skylight.

UAL949 United

LHR → SFO

· 2:14Quality 83side-on

3D replay

Software-steadied: the hops of the camera motor are smoothed out (plane wobble −57%). Download

Trace

Where the aircraft sat in the frame, second by second. Click the chart to jump the video there.

—FOV —az —el —pose —
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
73%
First lockfrom target selected
5.0 s
Centring, medianaz / el while locked
0.48° / 0.57°
Centring, 90th pctaz / el while locked
3.01° / 1.94°
Tightest field of viewhorizontal
4.1°
Time to 8°from first lock
8.8 s
Time to tightestfrom first lock
18.7 s
Time at telefield of view ≤ 5.5°
25.9 s
Jitter at teleaz / el, standard deviation
0.52° / 0.45°
Swing at teleaz / el, peak to peak
1.90° / 1.76°
Pan reversalsper 10 s at tele
0.0
Largest pan hopin any 1 s at tele
4.35°
Largest tilt hopin any 1 s at tele
1.76°
Pose error, mediancommand vs camera
0.65°
Largest correctionvision vs prediction
2.71°
Zoom steps
80

Aircraft & route

Flight
UAL949
Registration
—
Type
—
Airline
United
From
LHR · London
To
SFO · San Francisco
Ground speed
263 kt
Altitude at closest
11,200 ft
Vertical rate
—
Category
A5
ICAO hex
a7f4ec

Pass geometry

Max elevation
69.7°
Elevation at start → end
21.1° → 19.1°
Azimuth at start → end
328° 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
2:14 (134.0 s)
Lock
73%

Build & tuning

The tracker build that flew this pass and the live settings that mattered, so passes can be compared across changes.

Build
2026-10-13h — no zoom-focus direct while the lens is still zooming (wedge race)
Commit
181d1fa+wip
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
67.0 MB · 134.0 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