Hi @thho @katherine @ABraun
So in this sample How to prepare Sentinel-1 images stack for PSI/SBAS in SNAP 5
I use 12 Sentinel-1A I got 16000 PS after stamPS process. However recently I used 30 scene for the same area of study. The master selected is chosen by SNAP usin “InSAR Stack Overview”. However when doing stamPS process out of 500.000 (five hundred thousand PS candidate) stamps only chose 4000 PS the rest are weeded out. I use default parameters like my previous test and as @katherine suggested, although in her steps she recommended that if the data/interferogram more than12/13 to split the stack to two or more with same master but when I did this test I use all 30 data in one stack.
What may caused so many possible PS weeded out by StamPS?