Development of an algorithm for estimating snow hydrological parameters in wet snow areas using satellite-based SAR images

Abstract

The objective of this study is to develop an algorithm for quantitatively estimating snow hydrological parameters using a Synthetic Aperture Radar (SAR) mounted on a satellite and a numerical scattering model. Simultaneous RADARSAT SAR observations were carried out during the winter seasons of 1996 to 1998. The study area is located in the Hokuriku District, Niigata Prefecture, Japan, that is well known for having wet snow with a complicated layer structure from the beginning of the winter season. In previous studies, we sought to estimate the distributions of snow depth and surface roughness using these multi-temporal RADARSAT images. However, snow depths over 20cm were underestimated because the extinction effects at C-band microwave were too large. In this study, we develop an algorithm to estimate distributions of snow density and roughness using observation datasets with some parameterization techniques and assumptions. Furthermore, we show the possibility of inferring snow depths from combined parameters estimated with a L-band SAR image at test sites.