I perform the SAR Simulation Terrain Correction and now I would like to mask the areas of the S1 scene that are affected by the layover effect. The layover mask was created after the SAR Simulation Terrain Correction. Is there any way to do this in SNAP?
You can use the Mask Manager to do this. You can find it in the menu (View / Tool Windows / Mask Manager) or at the right side as a tab.
If you want to mask out this area you can change the valid-pixel expression for your band. The third option is to use the Land/Sea Mask operator.