New to using my P3P. Have a concern before using RTH: does the P3P use a barometric or a radar altimeter? The DJI P3P User Manual V1.6 makes no mention of the altimeter.


Is the RTH response related to a Radar altimeter or a Barometric altimeter? I am thinking it is a radar altimeter yet could it be a combination?

For example,

RTH altitude is set at 30 M; the takeoff home point is 240 M above sea level; a hill in the flight path is about 25 M above the home point:

The P3P ascends from its home point, then climbs to 10 M above the hill, then the battery is low, so, I press RTH. How will the P3P respond?
Will it ascend 5 more meters?
Will it ascend 20 more meters?
Will it remain at 35 meters (in relation to the starting home point) then come home?
Will it descend into the ground since its home point is barometrically greater than the RTH altitude?

The Phantom uses a barometer for altitude.
The only height your Phantom knows is Home = zero.
All other heights are in relation to height above or below home point.

When RTH is initiated, your Phantom will climb to whatever RTH height is set ... relative to the home point.
If the Phantom is higher than the  RTH height,  it will come straight home at that height.

labroides@yahoo Posted at 2016-4-21 08:47
The Phantom uses a barometer for altitude.
The only height your Phantom knows is Home = zero.
All ot ...

Thanks Labroides - that certainly simplifies things.