skylight.

UAL8205 United

Boeing 737NG 924ER/W · N39450 · SFO → ?

· 0:18Quality 54lost locknose/tail

3D replay

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
33%
First lockfrom target selected
12.2 s
Centring, medianaz / el while locked
0.10° / 0.13°
Centring, 90th pctaz / el while locked
0.25° / 0.34°
Tightest field of viewhorizontal
3.9°
Time to 8°from first lock
4.0 s
Time to tightestfrom first lock
—
Time at telefield of view ≤ 5.5°
1.3 s
Jitter at teleaz / el, standard deviation
—
Swing at teleaz / el, peak to peak
—
Pan reversalsper 10 s at tele
0.0
Largest pan hopin any 1 s at tele
—
Largest tilt hopin any 1 s at tele
—
Pose error, mediancommand vs camera
1.04°
Largest correctionvision vs prediction
0.45°
Zoom steps
31

Aircraft & route

Flight
UAL8205
Registration
N39450
Type
Boeing 737NG 924ER/W
Airline
United
From
SFO
To
—
Ground speed
297 kt
Altitude at closest
8,900 ft
Vertical rate
+2,752 ft/min
Category
A3
ICAO hex
a494c5

Pass geometry

Max elevation
17.9°
Elevation at start → end
17.9° → 14.9°
Azimuth at start → end
212° SSW → 206° SSW
Closest-approach azimuth
212° SSW
Minimum slant range
8.9 km
Heading at closest
187° S
Aspect at closest
nose/tail (25°)
Turn
straight (0°)
Departure
Yes — climbing out after take-off
Zenith pass
No
Dead-zone wrap
No
Duration
0:18 (18.1 s)
Lock
33%

Build & tuning

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

Build
2026-10-15t — vertical rate falls back to geom_rate (server)
Commit
218644c
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
6.9 MB · 14.0 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
-0.09
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