Is there a way to get the correct placement in the z-coordinate when doing photogrammetry without using GCP? I can get the x and y-coordinate correct but somehow I can't get the hight correct. I know it can't get "perfect" when only using the drones GNSS.
What I can gather, DJI use WGS 1984. The meta data from the images shows a altitude of 28 m, but the flight hight is somewhere between 60-80 m (can't remember). I have some GNSS readings the shows ground hight of about 45-47 m. I am using Drone2Map.
My question is - Are there a way to get a "correct" hight on my 3D model without using GCP?
When setting op the project in Drone2Map I have tried to change image coordinate system and output system. The effect is that the model is under or over the "correct" ground / GCP. I think that I am not using the correct datum / hight model for the images.
I have tried above Sea Level and belove for GPS altitude reference.
I have used another sets of images from a drone with RTK and images for another location. Still can't get the hight correct.
Hop that someone can help.