PSI method

I’m taking steps hardly and slowly in this part of my research , after I tried the interferogram stacking method many people advice me to apply PSI method and it was hard to me to set up Linux and MATLAB to apply snap to stamps, now my Dr suggest another software ( The Sentinel-1 interferometry processor is developed by the Radar Imaging Geodesy Group at Peking University)
and gamma software , what are the different between them and Snap to Stamps , and i think that Gamma software is not free , please if anyone can answer me ,thank you in advance

Once you create the interferograms using SNAP software, then using StaMPS software we can generate the Persistent Scatterer Interferometry.
Installation and processing steps are presented already in this forum.

so no need to try the suggestion software , thank you