In-flight Compass Problem

[Costa Rica Guy]

I just had my drone serviced for a Gimbal band replacement. Had to rebind the controller and all went well on pre-flight checklist and first easy flight, but.....about 3/4 of the way in i got a notification that compass needed calibration. I have had these before PRE_TAKEOFF, but never IN flight. By the time i returned, all was normal. Ready to fly again and all systems go. Took off and flew around some and got same notification. Upon return, all normal. How does one calibrate a compass when it is reading normal?

 

[Flawless]

If it's reading normal where you are, but asking for calibration when in flight, there are two possibilities:

More likely - interference at point of takeoff, either ferrous metal or electromagnetic, which stopped affecting your drone when it left its area of affect (and it asked for calibration).

Less likely - similar interference at point of warning.

Mavic compasses do an initialisation when powered on - if they're next to metal when powered on, but move away (before or after launch) then it can have very serious effects.

 

[Costa Rica Guy]

If it's reading normal where you are, but asking for calibration when in flight, there are two possibilities:

More likely - interference at point of takeoff, either ferrous metal or electromagnetic, which stopped affecting your drone when it left its area of affect (and it asked for calibration).

Less likely - similar interference at point of warning.

Mavic compasses do an initialisation when powered on - if they're next to metal when powered on, but move away (before or after launch) then it can have very serious effects.

I will try a short flight from a different location and see if i get same warning. What is worst case scenario of this in-flight? Can compass be calibrated if it is NOT showing "compass calibration" warning? Thanks for the help!

 

[msinger]

Can compass be calibrated if it is NOT showing "compass calibration" warning?

It can be calibrated as long as there are no magnetic metal objects near the compass. If there are, the compass calibration will fail after the second rotation.

 

[niki]

I just had my drone serviced for a Gimbal band replacement. Had to rebind the controller and all went well on pre-flight checklist and first easy flight, but.....about 3/4 of the way in i got a notification that compass needed calibration. I have had these before PRE_TAKEOFF, but never IN flight. By the time i returned, all was normal. Ready to fly again and all systems go. Took off and flew around some and got same notification. Upon return, all normal. How does one calibrate a compass when it is reading normal?

When I power up the Mavic at home and start moving it around the room by hand and get closer to the 8" speakers positioned on the side of the room I can see the compass error appearing and that error dissappear immediately after I move away from the speakers. I have flown many times after power up in the room and get some compass warning then go outside and all warnings are gone.
There are places that are always with high magnetic interference like big bridges and many other objects containing metals. There are also magnetic storms that can produce magnetic anomalies on a place you never had an issue. It is bad idea to calibrate the compass in both conditions. Compass calibration is recommended when you travel more than 200km from the previous place of calibration but even then you may want to skip calibration if there is no problem in a test flight.
By the way I never needed to calibrate the compass on the inspire or the mavic that I have for more than 2 years and a few times I was traveling more than 400km.
In my opinion If you get compass error on the ground it's better to move away to a place without the warnings an take off from there.
I'm checking the magnetic storms weather casts the day before flying so to know what to expect and is it safe at all. I'm using the UAV Forecast app to check the conditions, had to fly once in magnetic storm and got the compass error warning in mid flight and the drone was in atti mode for about a minute. That was the only time when I had a compass error midflight.

 

[sar104]

I just had my drone serviced for a Gimbal band replacement. Had to rebind the controller and all went well on pre-flight checklist and first easy flight, but.....about 3/4 of the way in i got a notification that compass needed calibration. I have had these before PRE_TAKEOFF, but never IN flight. By the time i returned, all was normal. Ready to fly again and all systems go. Took off and flew around some and got same notification. Upon return, all normal. How does one calibrate a compass when it is reading normal?

You would need to look at the flight log from the aircraft, which includes the raw magnetometer data to understand fully what was prompting the calibration notice. However, it may be happening when you instruct the aircraft to yaw, which is when any issues with the compass data really become apparent. Have you done a recalibration?