Just something ive been wondering about...

If i climb 800 meters and fly my drone off the edge of a cliff and descend down the mountain side, will i still be able to ascend to where i started or will the drone use the bottom of the mointain as its altitude? Meaning i couldnt go over the 120m/500m max height?

Theoritically, once you land and take off again the GPS will set that as your new home point, so it probably will use the bottom of the mountain to calculate it's altitude.  I believe you can override the 120m/500ft. max height in the DJI Go app, but not sure it would allow you to go the 800m back up.  

thats if you land and reinitiate it other wisw your alt will go to -#.

alt. is based on take off point

AlecW Posted at 2017-1-12 07:19
It's based on home point height which is zero feet/meters when you take off.  If you fly down 400 feet it will be a negative 400 feet.  If your RTH height is set to 100 feet and you pressed it, it would fly up 500 feet, fly to the home point and then down 100 feet and land.

It's using barometer not GPS to calculate height as far as I know.

Right.  But if he lands at the bottom, when he goes to take off again, it will reset his home point to the bottom, thus not allowing him to fly high enough to get it back, right?

AlecW Posted at 2017-1-12 11:14
That's how I understand it.  He could set max alt to 500M and fly back up after landing though.

He'd probabaly have to land somewhere halfway up to reset the home point again.  If 500m is max altitude and he climbed 800m, he'll be short of getting it back.

Ob1415 Posted at 2017-1-12 10:55
Right.  But if he lands at the bottom, when he goes to take off again, it will reset his home point to the bottom, thus not allowing him to fly high enough to get it back, right?

He didn't ask about landing down there.
You are making things unnecessarily confusing.

If you fly a real helicopter off a cliff and descend, it will be able to come back up anad is not affected in any way by whatever level the botttom is.
It's the same for your Phantom.

The unit wouldn't take negative integers into consideration when you are going downwards. You don't need to put in a maximum altitude, so you should be able to come back up it you follow post#2.

Labroides Posted at 2017-1-12 13:13
If you fly a real helicopter off a cliff and descend, it will be able to come back up anad is not affected in any way by whatever level the botttom is.
It's the same for your Phantom.

There are a lot of things you can do in a real helicopter that you can't do with a Phantom.
You are making things unnecessarily confusing.  LOL!

*No ill-intent, just having fun

Labroides Posted at 2017-1-12 13:13
If you fly a real helicopter off a cliff and descend, it will be able to come back up anad is not affected in any way by whatever level the botttom is.
It's the same for your Phantom.

There are a lot of things you can do in a real helicopter that you can't do with a Phantom.
You are making things unnecessarily confusing.  LOL!