Copter is Flying ~3m below the height set in Mission Planner

Using waypoint with a radius of 1m and a height of 6m the drone is consistently flying at ~3m high. Altitude is relative. Upon arming the height zeros and is zero again on landing.

Why the error?

1 Like

My guess is that the propellers change the air pressure measured by the barometer.
Protect the barometer from propwash.
And update to ArduCopter 4.2.0-rc3


Can’t do that with an APM Flight Controller.

1 Like

I’ll test some prop wash protection.
My main concern is repeatability between drones for collision avoidance.
Without affect from propwash the barometer seems to be repeatible to less than 50mm allowing for variation in atmosphere pressure. So one should be able to keep copters 1m apart in height quite accurately.

Thanks for the input.