I am trying to generate the velocity map using the Offset tracking tool on a pair of Cosmo Sky-Med data (Stripmap mode/SLC) but in the output of the DEM-Assissted Coregisteration (using SRTM) there are many gaps on the result (see attachment), in turns, then the output of Offset tracking is block. This happened for both the whole image and subset, and I also converted SLC to GRD mode and repeat the Coregistration again but I faced the same problem.
When I open the coregistered-result SNAP in the SARscape it seems Ok (see attachment)!
I use SNAP 5.
Thanks for your consideration.