isce-framework
Sentinel1.py is hard-coded for IW mode (no EW mode)
I am trying to use topsApp.py to generate an interferogram using two Sentinel-1A EW mode SLCs with the same spatial extent. This was a test prior to hopefully generating many, many more EW mode interferograms. After repeated attempts and errors with ISCE2 claiming no swaths contain burst overlaps and index errors for self.numberOfCommonBursts, I think I have traced the issue to Sentinel1.py, which appears to be hard-coded to only support IW mode SLCs. Here's a couple examples:
Sentinel1.py, lines 200-201
elif self.swathNumber not in [1,2,3]:
raise Exception('Swath number must be one out of [1,2,3]')
IW mode produces three sub-swaths, while EW mode produces five sub-swaths.
Sentinel1.py, lines 211-212
if len(self.xml) == 0:
swathid = 's1?-iw%d'%(self.swathNumber)
This IW hard-coding results in topsApp.py not finding any annotation.xml file for the swath, despite one being present and properly named for EW mode.
There may be other similar gotchas I haven't found yet.
Per ESA's S1 User Guide, S1 EW mode is supposed to be usable for interferometry in a very similar way to IW mode. I'd appreciate help in ensuring ISCE2 supports this correctly.
Someone would need to read the ESA documentation to determine what needs to be changed. All the ISCE developers are busy with preparing and testing ISCE3 for the launch of NISAR in a few months, so they are not going to have time to look at the Sentinel-1 EW mode processing any time soon. There are not many places where they acquire EW mode over land.
