Thank you so much for the suggestion.

About the reference point choosing, i still have a question. When i read the SARPROZ tutorial ‘Demo: APS Estimation Multitemporal analysis with Sarproz’, it says that best reference point should reflects that both velocity and residual height distribution peak at 0. However, in the Site Processing – APS module, i can see 25 auto reference candidate points. I checked every single one of them, and not any of them can do both – 0 peak at velocity ad residual height.

From the manual, it is very clear that i should choose a point on the ground and stable, which corresponding to residual height and velocity peak at 0. My questions is that when there is no such a point, which rule is preferrable. If choose a stable point, it could shows a bias in residual height distribution, like what i showed in the previous images.

Thank you again!!

Paul