SAR-data in water detection under vegetation

I have a problem in water detection under vegetation. Is it possible to detect water bodies under plants (for example, сane)? Simply, my task is to determine land under the vegetation, or it grows directly from under the water.

I understand that, due to the wavelength, doing this with Sentinel-1 data will be problematic , but may be it`s possible with ALOS-data.

Whether there is a manual on this topic or someone will write the procedure in the program here?