I have a problem processing a corridor mapped with a Phantom 4 Pro.
As it’s already known by Pix4D, altitude in DJI drones is faulty and can have swings of 100m. We were aware of that and recorded plenty of GCP to correct it.
The method I usually use is to mark 3 or 4 gcp, then reoptimize the model and mark the rest of the gcps.
The issue I have now, is that it seems Pix4D isn’t able to correct the large difference between the points and the image locations. If I manually lower the points by changing the height of the points coordinate system, the project processes and everything fits. But as soon as I insert the correct GCP locations, the model fails to adapt to the GCPs and I get many uncalibrated cameras and just a very poor reconstruction.
I tried lowering the vertical accuracy of the geotagging to 200m, but it does not help.
What is the recommended workflow with Phantom 4 Pro to deal with this error? Is there no fix to it?