Flight height question

[him7403]

If I start flying at top of mountain and then fly down does it go to negative height?
I'm assuming the height starts with 0 from starting altitude, not sea level.

Is there any issue flying at negative height?

 

[DoctorNick]

Yes it will go negative. Not really. But keep return to home altitude in mind

 

[old man mavic]

the drone does not know its height relative to the ground below it at any given time once it is out of downwards sensor range, with regards to RTH height it is the height above the home point not from where it is below the home point, just be aware of differing wind patterns around the slope and keep an eye on your sats as you can loose some as you descend down below the your take off point one final thing with the RTH if you are a long way below the home point then in the event of a RTH the drone will have to climb from that depth to the preset RTH height before it can come home so just be aware it will require more battery to do that so dont have a high RTH height set before take off and keep a good check on battery levels as well