I know this has been raised before but I have been unable to refind the answer. What altitude units are used in the Mission Planner and is it possible to change the units. I read that the default altitude is metres. Is that correct - can it be changed and if so how?
The reason for the question is that my arducopter has just flown into the top of a tree despite the planned altitude being 40(metres - I thought). The tree is not huge and I expected it to clear it easily. The log shows that it held the set altitude of 40 so I don't think there was a problem with the Arducopter and I am sure the tree is not 120feet high..
I was lucky that the Arducopter fell through the tree and was virtually undamaged although the log shows the ground by the tree was at an altitude of -13 - the ground is definitely lower than at the takeoff point but 13m (40feet) sounds a bit much.
Can anyone help me sort out what went wrong?