GPS glitch for unknown reason

ArduCopter Copter 4.1
1

Hey guys.

Yesterday I had a GPS glitch that I cannot explain.

The drone took off on an auto mission and when it got to 10m it started drifting. at some point, I saw a “GPS glitch” on MissionPlanner and landed the drone.

After that, I examine the flight logs to understand what caused this glitch and to my surprise, I saw that the data coming from the GPS was accurate. I made a plot of the location sources (AHR2, GPS) compared to the drone’s location estimate (POS). You can see that the POS plot has some “jumps” indicating there was a glitch in the location estimation.

Attached is the plot I made and the flight logs.

Thank you

Flight logs:
https://drive.google.com/file/d/1ss98-ktH4JHbJS7czcU8B8CdF6srOetb/view?usp=sharing
Plot:

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qqq1920×1080 205 KB

2

There is crazy solar weather happening just now, gps might be unreliable.

3

Another thing I notices is that the drone lost altitude while it was on ALT_HOLD mode.

4
  1. To fix the Alt hold issue, calibrate wind estimation according to the documentation
  2. Accept the fact that sometimes GPS receivers glitch, due to multipath, solar flares or EMI
  3. Update to ArduCopter 4.2.1
1 Like
5

Maybe similar to our problem some weeks ago?

6

I accept that fact but according to the flight logs, the glitch wasn’t on the GPS reading. When comparing the trajectory from the logs, the POS trajectory has several glitches and the GPS trajectory is smooth. another thing is that the sat count is fine throughout the whole flight. GPA also looks ok. any ideas where those glitches coming from?

7

Your compass is all over the place, heavily influenced by the throttle. No surprise that the EKF calculates a completely different trajectory from compass and acceleration then comparing that to the GPS confuses it.
Fix your compass location.