skylight.

UAL837 United

Boeing 777 300ER · N2748U · SFO → NRT

· 0:59Quality 70nose/tail

3D replay

Software-steadied: the hops of the camera motor are smoothed out (plane wobble −84%). 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
57%
First lockfrom target selected
21.3 s
Centring, medianaz / el while locked
0.56° / 0.37°
Centring, 90th pctaz / el while locked
2.45° / 2.56°
Tightest field of viewhorizontal
3.4°
Time to 8°from first lock
27.9 s
Time to tightestfrom first lock
—
Time at telefield of view ≤ 5.5°
6.6 s
Jitter at teleaz / el, standard deviation
0.09° / 0.10°
Swing at teleaz / el, peak to peak
0.20° / 0.22°
Pan reversalsper 10 s at tele
3.0
Largest pan hopin any 1 s at tele
0.61°
Largest tilt hopin any 1 s at tele
0.45°
Pose error, mediancommand vs camera
1.14°
Largest correctionvision vs prediction
0.86°
Zoom steps
48

Aircraft & route

Flight
UAL837
Registration
N2748U
Type
Boeing 777 300ER (B77W)
Airline
United
From
SFO · San Francisco
To
NRT · Tokyo
Ground speed
203 kt
Altitude at closest
1,050 ft
Vertical rate
+2,304 ft/min
Category
A5
ICAO hex
a2b8db

Pass geometry

Max elevation
81.6°
Elevation at start → end
0.2° → 11.8°
Azimuth at start → end
116° ESE → 299° WNW
Closest-approach azimuth
26° NNE
Minimum slant range
345 m
Heading at closest
297° WNW
Aspect at closest
nose/tail (5°)
Turn
straight (0°)
Departure
Yes — climbing out after take-off
Zenith pass
No
Dead-zone wrap
No
Duration
0:59 (59.1 s)
Lock
57%

Build & tuning

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

Build
2026-10-15p — selection hysteresis; auto-cal drops stale bias
Commit
b8aa462
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
27.6 MB · 57.0 s · offset -1.2 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
-0.16
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