I’ve just been working on a geology mapping project in a mountainous region with a phantom 3 pro. Generally we’ve been very happy with results. We’ve been flying up to 6 grid missions per day, plus some free-flight and getting very nice results. For the final output we would like to combine the data from all the days (8 or so) of surveying.
The problem I’m finding is that there is often a significant change in recorded elevation from one day to the next (presumably due to errors in the GPS exif data recorded by the phantom). So in the overlapping regions between days there is a strange artefact of a large area of ‘floating land’ , around 20m or so above the terrain.
I’d like to know the quickest method for correcting this. I’m not particularly concerned about the absolution elevation being exactly correct, but I’d like the overlapping regions between days to agree. Is there any way to subtract or add metres of elevation from an entire group of images or to raise or lower a part of a DEM? I hope this makes sense & I guess other people must have come across this issue before when surveying large areas of periods of several days.