Recently, I have been processing few of the datasets with GCP. Sometimes, I get high GCP RMSE value and sometimes it is very low, as good as, 2-8 cm in x,y and z.
One thing, I have observed is that when processing larger datasets, say like 150-300 Hectares, the RMSE value is little high. What could be the reason?
I usually mark around 4-5 photos with respect to each GCP. I hope that is sufficient enough to calibrate.
What are the factors that affect GCP RMSE values? How can I improve them?