skylight.

UAL1387 United

Boeing 737NG 924ER/W · N69824 · SFO → ?

· 0:37Quality 49soft focuslost lockside-on

3D replay

Software-steadied: the hops of the camera motor are smoothed out (plane wobble −71%). 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
17%
First lockfrom target selected
30.0 s
Centring, medianaz / el while locked
0.27° / 0.21°
Centring, 90th pctaz / el while locked
0.65° / 0.96°
Tightest field of viewhorizontal
4.1°
Time to 8°from first lock
3.3 s
Time to tightestfrom first lock
6.3 s
Time at telefield of view ≤ 5.5°
2.3 s
Jitter at teleaz / el, standard deviation
0.04° / 0.06°
Swing at teleaz / el, peak to peak
0.10° / 0.15°
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
1.66°
Largest correctionvision vs prediction
1.62°
Zoom steps
64

Aircraft & route

Flight
UAL1387
Registration
N69824
Type
Boeing 737NG 924ER/W
Airline
United
From
SFO
To
—
Ground speed
291 kt
Altitude at closest
7,225 ft
Vertical rate
+2,944 ft/min
Category
A3
ICAO hex
a94b29

Pass geometry

Max elevation
28.7°
Elevation at start → end
19.1° → 27.8°
Azimuth at start → end
312° NW → 247° WSW
Closest-approach azimuth
262° W
Minimum slant range
4.6 km
Heading at closest
181° S
Aspect at closest
side-on (81°)
Turn
straight (6°)
Departure
Yes — climbing out after take-off
Zenith pass
No
Dead-zone wrap
No
Duration
0:37 (36.6 s)
Lock
17%

Build & tuning

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

Build
2026-10-15q — drive speed latched at the lens position; measured speed bytes only; auto-cal keeps gains
Commit
44f2d6a
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
17.2 MB · 34.9 s · offset -0.8 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
-0.11
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