Capability assessment of Sentinel-1 bi-temporal dual polarimetric SAR data for inferences on snow density

Abstract

The snow water equivalent is a significant parameter in the determination of the hydrological potential of snow, which requires timely information on snow density and snow depth. For shallow snow depth, the C-band polarimetric synthetic aperture radar (SAR) data can be effectively utilized for the estimation of snow density. Although methods exist in the literature for the estimation of snow density, they are largely based on the exploitation of fully polarimetric SAR, which is mostly commercial and highly expensive. In this paper, we assess the capability of the Sentinel-1 polarimetric SAR data for determination of snow density using two bi-temporal dataset pairs based on a novel framework. The method is based on the derivation of incremental/decremental factors of the scattering matrix, which are related to the Fresnel transmission coefficients (FTC) and the attenuation constant. The snow density is determined using the permittivity derived from the inversion of the FTC. The experiments are also performed using RADARSAT2 datasets synchronized with field measurements. The results are observed to be in agreement with respect to the available in-situ measurements as determined by the coefficient of determination of 0.658 and 0.525 for the RADARSAT-2 and Sentinel-1 datasets, respectively.