Hi Alexey, thanks for staying with me on this issue. Below is the text from the first few lines of information exported from the exif information.
CoordinateSystem: GEOGCS["WGS 84",DATUM["World Geodetic System 1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9102"]],AUTHORITY["EPSG","4326"]]
#Label X/Longitude Y/Latitude Z/Altitude Error_(m) X_error Y_error Z_error X_est Y_est Z_est
DJI_0001.JPG -2.013795 52.343490 231.177000
DJI_0002.JPG -2.012605 52.344135 231.377000
In a previous reply you mentioned that the 50m difference looked about right between the geoids. Is the solution to find the elevation difference between the drone reference datum and the reference used to pick up the GCP's (OSTN15), and put this figure in the elevation offset? Is that how users are doing it?
Looking at the drone photo information and true UK datum height this is the breakdown:
The drone took a photo before take off and reported an altitude of 161.45m, the measured GNSS height was 167.20
The drone recorded it's photos at an exif reported altitude of 231.30, and the drone mission flight was to fly at 70m
The drone reported data of 161.45m(take off) + 70M(flight height) = 231.30(approx). These numbers make sense in relative reference to the drone data, but i'm not understanding how to match the elevation in the real world.
Ian
Thanks
Ian