Hi,
As far as I know, soil moisture retrieval has not been implemented in SNAP. There are a few methods that have been developed for retrieving sol moisture from SAR. These are the following:
- Soil moisture retrieval using
theoretical scattering model - Soil moisture retrieval using
semi-empirical scattering models - Soil moisture retrieval using
change detection - Soil moisture retrieval using
Interferometry - Soil moisture retrieval using
polarimetric parameters
The methods mentioned above are the ones that mostly used for retrieving soil moisture from SAR.
Here are some relevant articles to look at:
https://www.tandfonline.com/doi/abs/10.1080/01431161.2013.813654