PX4 Generic Quadcopter · 2025-09-18

Flight telemetry summary

Distance Meters

1868.3 m

Maximum Altitude AGL

1268.9 m

Maximum Ground Speed

0.01 m/s

Minimum Battery Percent

54.5%

Minimum Battery Voltage

45.31 V

Minimum GPS Satellites

0

Maximum GPS HDOP

99.99

Flight Modes

ALTCTL

Maximum Distance From Home Meters

1623.7 m

Maximum Distance From Home Time

2m 58s

Average Ground Speed

0 m/s

Maximum Climb Rate MPS

0 m/s

Maximum Descent Rate MPS

-0.01 m/s

Voltage Sag

0.19 V

Flight Mode Seconds

ALTCTL: 3m 44s

Maximum GForce

1.02 g

EKF Healthy

Yes

Weather at the flight

Source

open-meteo-archive

Sampled At Utc

2025-09-18T22:00Z

Latitude

50.76

Longitude

36.25

Temperature C

13.4 °C

Wind Speed MPS

3.85 m/s

Wind Direction Degrees

2

Wind Direction Cardinal

N

Weather Code

3

Weather Description

Overcast

AI flight report

This flight ran 3:43 and stayed in ALTCTL the whole time, climbing steadily from the home position (50.76115, 36.25242, 1495 m MSL) up to a maximum altitude of 1269 m above home by around 2:58-3:00, where it then held level for the rest of the log. The track covered 1868 m of distance, with the farthest point from home (1624 m) reached at 2:58. Oddly, the speed and vertical-speed fields report 0.0 m/s throughout, even while altitude was clearly climbing several hundred meters between samples (e.g. 575.6 m at 1:00 up to 1268.9 m by 3:00) — that's almost certainly a logging or derived-field artifact rather than a real hover-climb, since the altitude trace itself is moving. Weather was mild and calm-ish: 13.4°C, wind 3.85 m/s from the north, overcast skies.

The most concerning pattern is around 2:58-3:00, where GPS satellite count collapsed to 0 and HDOP pegged at 99.99, triggering a critical LOW_SATELLITES event at 2:58 (5 sats) immediately followed by a full dropout. This coincides with the same window where the largest barometric-vs-fused altitude gap of 1101.2 m was recorded at 2:59 — right after the aircraft reached its logged maximum altitude. That's a big enough disagreement between independent altitude sources that one of them is very likely wrong at that moment, and it's suspicious that it lines up exactly with the GPS blackout; a GPS-fed altitude fusion losing its input could easily explain a jump like that. There's also an early ALTITUDE_DISAGREEMENT warning at 0:00 (169 m gap) and repeated GPS_DEGRADED warnings at 0:10 and 0:41 (HDOP 2.3), suggesting the GPS lock was marginal from the very start of the flight, not just at altitude.

Battery held up fine — 54-55% and 45.3-45.6 V throughout, with the recorded minimum (45.31 V) at 1:04, well within normal range and not a factor in anything else that happened.

Given that GPS satellite count and HDOP were already borderline at takeoff (8 sats, HDOP ~1.7-2.3) and then fully collapsed to 0 sats/HDOP 99.99 right at peak altitude near 3:00, I'd treat this flight's altitude data from about 2:58 onward as unreliable and worth cross-checking against a barometer-only or raw GPS log if available, rather than trusting the fused altitude number. It would also be worth checking whether something about the climb itself — antenna orientation, attitude, or a nearby obstruction — caused the satellite dropout, since it happened at the exact moment the vehicle reached its highest point, and knowing whether that's a recurring altitude-linked GPS weakness on this airframe would settle whether it's a one-off or a real pattern to watch.

Detected flight events

1. 0s — Barometric and fused altitude disagree by 169 m

   Barometric and fused altitude disagree by 169 m

2. 10s — GPS quality degraded (HDOP 2.3)

   GPS quality degraded (HDOP 2.3). Position accuracy is temporarily reduced; the flight controller keeps estimating position from other sensors.

3. 41s — GPS quality degraded (HDOP 2.3)

   GPS quality degraded (HDOP 2.3). Position accuracy is temporarily reduced; the flight controller keeps estimating position from other sensors.

4. 2m 58s — Maximum altitude: 1269 m above home

   Maximum altitude: 1269 m above home — the highest point of this flight.

5. 2m 58s — Low satellite count (5)

   Low satellite count (5). Position hold may be unreliable until reception recovers.