Camera Calibration Parameters And Covariance Matrix

[a.f.]

Hello everyone,

I have a quick question. When aligning and optimizing camera positions, Metashape adjusts the radial distortion parameters k1, k2, k3 and k4 for each camera calibration group.
Are those the same parameters that are used in 'reconstruction uncertainty' gradual selection? And are they calculated for each tie point?
I guess what I really ask is: what does the covariance matrix consist of?

Thanks in advance!
Cheers