Snow Water Equivalent Estimation using Differential SAR Interferometry and Co-Polar Phase Differences from Airborne SAR Data

Abstract

The Snow Water Equivalent (SWE) describes the amount of liquid water stored in a snow pack and is an important parameter for runoff predictions and flood forecasts. Differential Interferometric Synthetic Aperture Radar (DInSAR) can be used to estimate the SWE change between two temporally separated repeat pass SAR acquisitions utilizing the interferometric phase. However, only a limited range of SWE changes can be retrieved unambiguously due to phase wraps of the interferometric phase. In this study, the aim is to include information on snow depth obtained from the Co-polar Phase Difference (CPD) between the polarimetric channels to detect phase wraps and improve the SWE retrieval results. The investigations are performed using airborne SAR acquisitions over the Alps.