Page 1 of 1

Flight plan doesn't cover area in top down

Posted: Tue Dec 03, 2019 8:28 am
by RobCleaver
When the flight plan was created it didn't cover all of the are.


I've planned similarly large and hilly flights without this issue happening. Any ideas as to the cause or cure?

EDIT: I've set the take-off point lower down the hill and the flight plan covers the whole area. 110m elevation change from top to botom. Do you know what causes this?



Re: Flight plan doesn't cover area in top down

Posted: Fri Jan 10, 2020 10:15 am
by gil_dh

The reason for the incomplete coverage when liftoff is not the lowest point in the terrain is that we currently do not support negative altitudes. Since 0 altitude is the point where drone liftoffs and we cannot go below 0 altitude in waypoints (actually 1 meters is the lowest allowed value at the moment) - you get incomplete coverage in the lower parts of the terrain.

Example to explain:

* Say you have a terrain with elevation difference of 200 meters from lowest to highest points in the terrain.
* You set liftoff from a point that is 100 meters above the lowest point in the terrain.
* You fly 50 meters AGL.
-> this means that there will be points that will not be covered since some points will be at relative -50 meters AGL (and some at -40, -30 etc).

So to summarize: you should consider the relative difference in altitudes and the altitude of planned flight when selecting liftoff point. It does not have to be the lowest point, but the relative altitude of this point minus the flight altitude should be above 0.

We have plans for this year to support negative altitudes, then this problem will go away.

DH Team