I have 3 different sets of photos (1. aerial nadir at 200', 2. aerial oblique at 150', 3. iphone ground photos). I've AT'd all three sets in separate blocks, in the nadir set I established tie points, imported them into the other two blocks as CP's, the two blocks with the CP's will allow me to merge them, but the merge is greyed out when I try to merge the original tie point set (nadir)?? Should I have turned those to CP's at some point, no directions on any forums stated to do that?
You can run AT all three dataset in the one block but with tie points which to connect datasets. But everything is up to how you ensured accuracy of the your data