ANSWERS TO YOUR
TECHNICAL QUESTIONS.
Why should I perform more than one bundle adjustment step?
There are three common situations for which more than one iteration may be required:
1. You want to run a first iteration of bundle adjustment without GCPs, and then run a second bundle adjustment with GCPs (e.g. troubleshooting, large projects, GCPs available at a later stage).
2. In cases for which you want to highly constrain bundle adjustment parameters, this may require running 2-3 bundle adjustments to reach the optimal solution.
3. If a first bundle adjustment is necessary to account for large adjustments on the EO parameters (such as large offsets in the image positions, important adjustments on the attitude angle, 90 or 180 kappa rotations), it can be a good idea to follow with a second adjustment to fine tune the solution after the large adjustments of the first pass.