I see that there is a GDAL driver for Sentinel-1 'manifest.safe' and I tested it against the tough case of the SLC (complex).
These products consists of three HH-HV dual-pol images. They only overlap at the edges, when I load the *.tiff one by one in OpenEV viewer (see
attached screen shot)
However when I load the 'manifest.safe', GDAL recognizes that it is Sentinel-1 but its georeferencing is wrong. Three images are overlapped almost 100%. When I run gdalinfo, the shown GCPs
are only from the 3rd image (s1a-iw3-slc-vh-########-003.tiff).
Also the new RCM is going to have the 'manifest.safe' file too. There could be a conflict, if file name 'manifest.safe' is used to identify the sensors.