Estimation of Snow Cover Parameters by ALOS-2 PALSAR Interferometry

Abstract

An applicability of spaceborne radar interferometry for the measurements of snow layer thickness and snow water equivalent was studied. Experimental dataset in the measurements of thickness and snow water equivalent consisted of two datasets from ALOS-2 PALSAR observations made in snow free conditions and in the presence of snow cover. Theoretical relations between interferometric phase difference, snow layer thickness and snow water equivalent for a given observation geometry and radar signal wavelength are presented. An essential feature of the experiment was the deployment at the test field of the reference corner reflector having stable level of radar cross section and scattered signal phase center location. Its interferometric phase difference was used as reference in calculations of the phase differences induced by snow cover on the test field. The calculations of snow depth made using theoretical relations, interferometric phase difference measurements, as well as direct measurements of snow layer thickness at the test field are in good agreement.