Drone2Map Ortho showing wrong Z heights.

Anonymous User

Hi all,

I have a colleague who has tried to create a 2D ortho of some images. When he uses the Rapid function, data is in the correct Z (height). Howver when he uses the more elaborate 2D ortho option, and just uses standard settings - his ortho and the basemap are suddenly 40 meters higher... 

Any thoughts on why this could happen?

Bill_VS

If it was flown with a DJI drone, they tend to use the wrong datum for elevation, and can be off by more than 50m vertically. In Pix4Dmapper, I correct this by editing the imagery input table (the one with the EXIF values). I don't use Drone2Map, but I hear it was based on the Pix4D engine, so it might have a similar interface at the beginning of the orthorectification process. You can use a single value to approximate height, or If you want to get more accurate, you could take one ground shot before takeoff, and subtract the AGL elevation of that ground shot (should be 0) from all subsequent values. I've found the approximation method works just fine for my purposes, though.