Hello everyone, I would like to ask you some simple questions: (1) if I use high-quality DEM for Doppler terrain correction, does the decibeled sigma reduce the influence of surface roughness to the greatest extent, like this： [question] (2) I would like to ask you why the backscattering coefficient…

Two things are important here: as stated in the SNAP histogram, these are just “rough statistics” (calculated from a subset of all pixels), so there is no guarantee that the given numbers are the true min/max values. If you want to go sure, you have to use the statistics tool which calculates sta…

The maximum and minimum values of backscatter coefficient obtained in snap are different in GIS

yes, this is correct. It is described at more detail here:

https://forum.step.esa.int/t/terrain-flattering-sigma0-beta0-and-gamma0/
Nominal incidence uncorrected sigma nought - #2 by peter.meadows
Radiometric & Geometric Correction Workflow - #71 by ABraun