I just tried your workflow. But with different data S3 OLCI and not with Terrain-Correction but just with Reprojection, but I used AUTO:42001.
That’s my gpt call:
gpt Reproject -Pcrs=AUTO:42001 -t G:\EOData\temp\utm-auto-test.tif G:\EOData\temp\subset_0_of_S3A_OL_1_EFR____20190214T070944_20190214T071244_20190215T112348_0179_041_220_2160_LN1_O_NT_002.dim
and that’s the output of gdalinfo:
utm-auto-test-gdal-info.txt (1.7 KB)
So, in general it works. The GeoTiff can store the information.
Maybe there is something special with the S1 data or the terrain correction.
@lveci can you check what’s going on?