I am having issues generating an accurate AT. I have investigated and tried different settings but with no luck. I'm not sure if its a issue with the CC software or the accuracy of the photos....
I have 3 x DJI Phantom 4 RTK datasets covering 2 sites (1 site surveyed twice). The first datasets for the two sites produced an accurate model compared to the check points we collected. However for the 3rd dataset for the site we surveyed twice keeps producing an AT which is 15m below the check points and the previews dataset AT. The AT settings are exactly the same but the focal length keeps changing and is >15% than the one for the P4 RTK (8.8m which changes to 10.59mm after AT. I have tried 4 different AT's using different settings such as Keeping camera properties or changing the Adjustment constraints/final rigid registrations.
Following the SIG advice re AT settings when using accurate RTK datasets I used the settings as per the screenshot below (which like I say worked fine for the first site visit datasets). Note, I cannot use the check points as control points for these projects as these were not collected at locations I can select in the photos, i.e. no GCP boards/paint etc were used.
Below are screenshots from the same site (Site A) with the two datasets collected a week or so apart. Second dataset is the one with issues. Notice the settings are the same, but the focal length changes/is different and you can see a larger offset from the checkpoints, ~15m out (checkpoints are from same dataset for both projects, i.e. collected once).
Site A: First flight dataset - Before AT
Flight height = ~70m (10m higher than the second dataset). 211 - 70 = 141m
Site A: First flight dataset - After AT
Site A: Second flight dataset - Before AT
Flight height = ~60m (10m lower than the first dataset). 201 - 60 = 141m (same as above)
Site A: Second flight dataset - After AT