Effect of snow wetness to C-band backscatter-a modeling approach

Snow cover has a substantial impact on processes regarding the interaction between atmosphere and surface; thus, the knowledge of snow parameters is important for climatology, meteorology, flood prevention and the hydropower industry. The applicability of active microwave remote sensing for snow monitoring has been investigated for years. However, none has analyzed the effect of various snow characteristics to the accuracy of SAR-based snow extent estimation during the melting season. Previous studies have mainly shown results obtained by comparing SAR derived snow extent estimates with ground surveys. This paper presents a simple snow backscattering model and its combination with the semi-empirical forest backscattering model. The model is validated with HUTSCAT scatterometer and ERS-I measurements conducted in the Sodankyla test site. With the model predictions the effect of several parameters affecting the accuracy of snow extent monitoring by radar is analyzed