Modeling and observation of polarimetric SAR response to dry snow

Snow water equivalence (SWE) is one of the most important parameters for hydrological investigations. In this study, the authors show (1) a method of using stereological technique to determine snow parameters for microwave modeling, (2) comparison of NASA/JPL AIRSAR measurements with the model predictions and the numerical simulations of the relationships between the backscattering signals and snow physical parameters. The results indicate that the relationship between the co-polarization signals and snow water equivalence can be either positive or negative depending on the snow physical parameters, ground surface parameters and incidence angle. At C-band, the major scattering source is the interface between the snow and ground. X-band or higher frequency SAR sensor is needed for snow depth measurement