I'd really appreciate talking this through with someone.
Where do the image geotag coordinates come from?
From what I've read online EXIF metadata. I'm using a DJI Drone, so I also know that the altitude needs to be adjusted in Drone2Map. I've also been experimenting with this, as I input 197ft as my flight altitude, and my altitude from Image Table goes from ~22 to ~60m. Which I feel makes sense, my only question is: Online I've read the "height is in reference to the ellipsoid" because of GPS and "height is relative to the ground" meaning where you took off was considered "0 elevation". So if anyone has a better/clearer explanation for this, I would appreciate it!
Where do the GCP coordinates come from?
We used two Trimble R9 base stations. I processed them through CSRS-PPP, and I'm actually struggling with this part. The older version of Drone2Map had a "Ellipsoid" and "Height above ellipsoid" option, but with the June updated and Advanced License that is no longer options. After processing these surveys I want to compare them to past DEMs, so I'd like to build them in Ellipsoidal and later convert them to any geoid. But now, I need to find a way to use NAD1983 UTM Zone 15N and the Ellipsoidal Height.
If I choose NAD 1983 UTM Zone 15N, Drone2Map wont let me choose any Ellipsoidal-based vertical Coordinate System besides NAD 1983.