I noticed that outside of the empty pscands.* files I was also seeing a Segmentation Fault (core dumped) error message while running mt_prep_isce
I referenced this snap forum to address this:
Solved by
Installing g+±7 and gcc-7 (just incase, to make sure both are present)
Changing the compiler from CC = g++ to CC = g+±7 in the StaMPS_master/src/Makefile
cd StaMPS_master/src
make
make install
my PATCH_* pscands.* files are no longer empty