I’m trying to geocode/terrain-correct RCM GRD data that cover the North Pole via the SNAP GUI (SNAP 9.0.8, s1tbx 9.0.4) and am not getting any results. I’m using the “Range-Doppler Terrain Correction” process in an effort to receive an image that is correctly projected to the surface of the ocean, instead of an image in radar geometry with only tie points attached (i.e. GRD). I’m using the GETASSE30 DEM and I’m unchecking the “mask areas without elevation” box as it is often my workflow to geocode images over open ocean. EPSG:3413 is selected as a “Predefined CRS” in the “Map Projection” dialogue.
When clicking “run”, the progress bar stalls after some time (usually towards the end) and I can’t close the “Writing Target Product” window. After some time (enough time for the process to finish) I kill the process and try to load the result image, but QGis tells be that reading it failed. The behaviour is observed when trying this with other methods like an average height ellipsoid correction.
However if I subset the GRD image in azimuth direction such that it does not extent as close to / over the pole anymore, the TC works as expected.
I’m guessing from this that the TC process can’t properly handle data north of some threshold around 89° or so. Or is there something that I’m missing?
A good example is “RCM1_OK2776036_PK2924960_1_SCLND_20240130_043334_HH_HV_GRD”. It can be easily found in the EODMS graphical search mask by looking for “Low Noise” data with a relative orbit of 108 and the point “87N, 137E” as an area of interest.
Can someone confirm this behaviour and tell me whether this is a bug?