We are processing a flight with GCPs and we have one area of our flight that is giving us an error or different in the GCPs elevations and the computed elevations of more than 5 feet and another of 13 plus feet. We have tried everything to correct this and cant seem to get it to work. We are up against a hard deadline and cant afford to lose this client or contract.
This is what one GCPs are doing, how do I get it it recognize the elevation on the GCP, not the computed?
Hi mccune.drone,
as Pix4D customer, I understand that GCPs are used as Automatic Tie Points during the Calibration step, but with a stronger weight; if you want to add more weight to certain selected GCPs, you should arbitrary increase the Accuracy values.
Because Pix4DMapper is trying to fit the transformation as better as possible to all the GCPs alltogether, there are two main possibilities: one of the surveyed coordinates has a typing error (i.e. 476 instead of 467), or there is more than one camera setting (i.e., changing batteries in a P4RTK triggers the Lens Correction, even if you disabled it during the last flight).
If you have more than 5 GCPs, you should try to cycle three Calibration processes, and in each iteration, you should change a couple of GCPs to Check Points: in this way, you could be able to indentify if one of the affected GCPs had a typo.
Regards,
Giancarlo