Altitude

[CannibalRobotics]

Does anyone have a good explanation of how or where the altitude number is measured from when entering waypoints.
I get a default value of 98 feet plugged in but in Austin, we are at roughly 700 feet asl, up to 900+ in the hills. I've flown a few routes successfully but none of the numbers seem to line up on altitude. When the quad flies the route, its indicated altitude just does not line up.

 

[Dirty Bird]

I believe it just takes the starting altitude on setting the Home Point as 0' (give or take a few feet) and everything else goes from there. So if you set your Home Point and launched from a point 1000' ASL, the altimeter would show ~0'. If you set your first waypoint for 200' it will be 200' above that, or roughly 1200' ASL in this example.

 

[rbhamilton]

Yep. The numbers are supposed to be "AGL" Above Ground Level not ASL. You have to be careful when flying up or down a hill because the phantom can't really do super accurate measurements. Mine is usually plus or minus 30 feet.

 

[Meta4]

The Phantom doesn't display altitude AGL because it has no idea where the ground is.
It's altitude is relative to home point.
If you are flying in a flat area the calculations are easier but if there are hills etc you'll have to factor that into your calculations.