A method to estimate Snow Water Equivalent using multi-angle X-band radar observations

Active microwave sensors, especially high-frequency radar systems, are highly sensitive to snow pack parameters, including Snow Water Equivalent (SWE). With the availability of several X-band space-borne SAR systems, the study attempts to make use of multiple-angle SAR observations and develop relevant SWE inversion algorithms. Analysis was carried out based on parameterized scattering models for both soil surface and snowpack. It is found that the backscattering signals at two incident angles are well correlated for both soil surface and snowpack; and snow optical thickness can be well defined and estimated through snow volume scattering at two different angles. The snow and soil parameters can be estimated through two pairs of adjacent observations. The technique was tested using theoretical simulated database. Initial analysis shows that current technique needs to be further improved and a better estimation of single scattering albedo is needed.