SRP (Subtract Reference Phase) is after producing the interferogram and
you have subtracted the phase Earth phase.
SRD (Subtract Reference DEM) is after topographic phase removal.
The band dimensions should be the same either way. I think the bad
linelength error may be related to passing snaphu a wrong dimension.
Double check that the snaphu command in teh snaphu.conf file corresponds
to this product and the dimensions are the same as the band.