Remove topography from Image

hello , I would like to know if I can remove topographie from Image sentinel 1A GRD ?

if you mean the radiometric distortions caused by topograpy, you first have to calibrate to Beta0 and then apply the Terrain Flattening module.

Please have a look here:

GRD > Calibrate to S0 > RD Terrain Correction:

GRD > Calibrate to B0 > Terrain Flattening > RD Terrain Correction: