Scene edge artifacts

snap 5.0
granule : S1A_IW_GRDH_1SDV_20150513T063633_20150513T063658_005899_007992_8ED3.zip
After terrain correction, there is a strip of low s0 artifacts (on the right edge of the example below, over Morroco in Africa). GRD and calibration output do not have the artifact. I guess the artifact has to do with projection when elevation is non-zero. Could you explain why it occurs? Is there a way to remove?