Temporal snowpack density mapping using C-band multi-polarization ASAR data

Radar remote sensing has great potential to determine the extent and properties of snow cover. Availability of spaceborne sensor dual-polarization C-band data of ENVISAT- ASAR can enhance the accuracy in measurement of snow physical parameters as compared to single polarization data measurement. This study shows the capability of C-band SAR data for estimating dry snow density over snow covered rugged terrain in Himalayan region. The snow density is an important parameter for the snow hydrology and avalanche forecasting related studies. An algorithm has been developed for estimating snow density, based on snow volume scattering and snow-ground scattering components. The radar backscattering coefficients of both HH and VV polarization and incidence angle are used as inputs in the algorithm to provide the snow dielectric constant which can be used to derive snow density using Looyenga´s, semi empirical formula. Comparison was made between snow density estimated from algorithm using ENVISAT-ASAR HH and HH polarization data and the measured field value. The mean absolute error between estimated and measured snow density was found to be 24.38 kg/m³.