skylight.

UAL751 United

Boeing 737NG 800/W · N78540 · SFO → ?

· 1:16Quality 81lost lockside-onturned left 16°Dead-zone wrap

3D replay

Software-steadied: the hops of the camera motor are smoothed out (plane wobble −48%). 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
58%
First lockfrom target selected
9.6 s
Centring, medianaz / el while locked
0.30° / 0.32°
Centring, 90th pctaz / el while locked
2.64° / 0.98°
Tightest field of viewhorizontal
3.4°
Time to 8°from first lock
4.7 s
Time to tightestfrom first lock
56.6 s
Time at telefield of view ≤ 5.5°
27.2 s
Jitter at teleaz / el, standard deviation
0.30° / 0.34°
Swing at teleaz / el, peak to peak
1.89° / 1.64°
Pan reversalsper 10 s at tele
0.0
Largest pan hopin any 1 s at tele
9.65°
Largest tilt hopin any 1 s at tele
4.01°
Pose error, mediancommand vs camera
0.99°
Largest correctionvision vs prediction
0.61°
Zoom steps
44

Aircraft & route

Flight
UAL751
Registration
N78540
Type
Boeing 737NG 800/W
Airline
United
From
SFO
To
—
Ground speed
291 kt
Altitude at closest
7,400 ft
Vertical rate
+3,328 ft/min
Category
A3
ICAO hex
aaa616

Pass geometry

Max elevation
38.0°
Elevation at start → end
27.4° → 18.7°
Azimuth at start → end
307° NW → 193° SSW
Closest-approach azimuth
259° W
Minimum slant range
3.7 km
Heading at closest
176° S
Aspect at closest
side-on (84°)
Turn
turned left 16°
Departure
Yes — climbing out after take-off
Zenith pass
No
Dead-zone wrap
Yes — pan pre-positioned across the stop
Duration
1:16 (76.2 s)
Lock
58%

Build & tuning

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

Build
2026-10-14k — loop integrates real tick time; aim lead −0.2 s
Commit
33c2b35-k
Node
v22.22.2
Camera
TONGVEO 20x PTZ · 1920×1080 @ 30 fps
Clip
38.0 MB · 76.0 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
-0.28
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