I need help with strange CC behaviour...can't track it down to the source of the problem. I have set of photographs done by drone with GPs positions in meta data.
CC reads it as WGS and this is what I'm getting:
same as above but converted to OSGB:
My GPS altitiude is set to Sea Level:
Now as you can see Z values are all out of the place...image was taken ca. 53m above ground, CC reads it as 0.6m, OSGB shows -53m and funny thing is that we have GCP which are like:
So GCP and image Z value are correct but CC seems to have hard times trying to interpret them. This makes GCP totally unusable cos after AT my model is like 30m below GCP and CC fails to match GCP locations with any of the photograph...so after all I'm ending up with 3D model correctly sitting in X,Y but Z is a total abstraction. I checked the same photographs in two Cc versions 188.8.131.526 and 184.108.40.2064 and results are the same...
Any idea what is wrong ??.
The height values can be way off(+/- 100m) if using drone without RTK/PPK even if LatLon/XY seems correct. You could adjust height if you have known relative altitude from altimeter.
Funny thing here is that DjI RTK was used...and this doesn't explain why CC can't apply Z values given in photo EXIF data ??
Regarding altimeter..most modern DJI drones have it on board so height values are in relation to GPS+altimeter so chances for it being +/- 100m are close to zero.
Are you sure that Image EXIF contains corrected values from RTK?
Suspect you are looking at ellipsoid versus geoid .. your SRS in context will likely be WGS + vertical override .. can DJI give you an ellipsoid height?
Turned out EXIF data is so wrong that is unusable and I had to do Arbitrary AT then add GCP and then AT again...DJI drones can't save RTK data to EXIF. After all I was hoping for initial AT based on exif data to speed up GCP set up process but It didn't work that way.
Answer Verified By: Krzysztof Ciacka