I am using snappy to generate S1 interferograms.
I do back-geocoding and then ESD to generate a co-registered pair.
I then chain up the Interferogram > TOPSAR-Deburst>TopoPhaseRemoval modules.
I do NOT remove topohase during the interferogram generation step.
I pass the following external DEM parameters to TopoPhaseRemoval
parameters.put(“demName”, “External DEM”)
The interferogram is then generated but in the processing metadata it reports that “demName” as “SRTM 3sec”.
I did not catch this problem at first and I have generated more than a thousand Interferograms. All of them have been flattened using the SRTM 3sec instead of the external DEM (not even SRTM 1 sec).
Is the “remove topography” during the interferogram generation step preferred over the TopoPhaseRemoval tool?
Can you please look into the apply external DEM with that tool? Particularly with Snappy - I suspect it happens with the GUI and GPT too but have not tested extensively.
This is a pretty bad bug if the user expected to use a high resolution DEM but instead ends up with SRTM 3sec