Offset after Terrain correction


While testing Sentinel-1 data I’ve noticed that after performing Terrain correction (in S1tbx) the processed image contains offset compared to other non-Sentinel-1 data with the same projection. After noticing this issue I processed multiple Sentinel-1 scenes and found out that the offset is irregular between different scenes (scenes from different dates).

Processed files: Level-1 GRD product and IW mode.

Processing steps: -> apply orbit file (Sentinel precise) -> Calibration -> Speckle Filter (Refined Lee) -> Terrain correction (with SRTM 1sec grid, UTM/WGS 84 (Automatic))

It seems that the issue appears during the process of geocoding. What could cause this kind of effect?

Seems, that this issue is related with previously posted SRTM DEM displacement.

1 Like