Level
Normal position the aircraft would maintain when sitting
right side up.
Upside down
Exactly what it sounds like: flip the aircraft upside down from
how it would normally sit.
Nose down
The front of the drone pointed straight down toward the
ground with the tail sticking straight up.
Nose up
The tail of the aircraft pointed straight down with the nose
pointed straight up.
Left
The left side of the aircraft pointing straight down with the
right side pointed straight up.
Right
The right side of the aircraft pointed straight down with the
left side point straight up.
Figure 9-9. Calibrate accelerometer.
ArduPilot Mega (APM) Setup 139