Retrieval of snow parameters from Ku-band and X-band radar backscatter measurements

Techniques for the retrieval of snow properties from Ku- and X-band radar backscatter measurements were investigated. The work contributes to feasibility studies for the CoReH₂O satellite mission of ESA for which a dual frequency SAR, operating at Ku-band (17.2 GHz) and X-band (9.6 GHz), VV and VH polarizations, is proposed. A main parameter to be measured is the snow water equivalent (SWE). For the retrieval of SWE it is necessary to separate the backscatter contributions of the snow volume and the background target and to account for effects of snow grain size. The current version of the SWE retrieval algorithm applies the maximum likelihood approach matching radiative transfer forward computations with measured backscatter data. An application example for SWE retrieval is shown for the Cold Land Processes Experiment (CLPX-II) in Alaska, using Ku-band data of the NASA-JPL PolScat and X-band data of the TerraSAR-X satellite as input.