skylight.

UAL809 United

Boeing 777 300ER · N2846U · SFO → ?

· 0:54Quality 80side-on

3D replay

Software-steadied: the hops of the camera motor are smoothed out (plane wobble −85%). 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
74%
First lockfrom target selected
6.0 s
Centring, medianaz / el while locked
0.57° / 0.60°
Centring, 90th pctaz / el while locked
2.32° / 5.41°
Tightest field of viewhorizontal
6.6°
Time to 8°from first lock
40.0 s
Time to tightestfrom first lock
40.7 s
Time at telefield of view ≤ 5.5°
0.0 s
Jitter at teleaz / el, standard deviation
—
Swing at teleaz / el, peak to peak
—
Pan reversalsper 10 s at tele
—
Largest pan hopin any 1 s at tele
—
Largest tilt hopin any 1 s at tele
—
Pose error, mediancommand vs camera
1.16°
Largest correctionvision vs prediction
1.38°
Zoom steps
45

Aircraft & route

Flight
UAL809
Registration
N2846U
Type
Boeing 777 300ER (B77W)
Airline
United
From
SFO
To
—
Ground speed
202 kt
Altitude at closest
1,075 ft
Vertical rate
+2,240 ft/min
Category
A5
ICAO hex
a2e014

Pass geometry

Max elevation
78.7°
Elevation at start → end
0.4° → 11.7°
Azimuth at start → end
116° ESE → 299° WNW
Closest-approach azimuth
24° NNE
Minimum slant range
367 m
Heading at closest
298° WNW
Aspect at closest
side-on (86°)
Turn
straight (0°)
Departure
Yes — climbing out after take-off
Zenith pass
No
Dead-zone wrap
No
Duration
0:54 (54.2 s)
Lock
74%

Build & tuning

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

Build
2026-10-16d — interleaved A/B (experiment mountPrior)
Commit
221ec3f
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
53.6 MB · 54.0 s · offset -1.3 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
-0.1
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