Derivation of near surface soil moisture patterns from ENVISAT ASAR data

Water and energy fluxes at the interface between the land surface and atmosphere are strongly depending on the surface soil moisture content which is highly variable in space and time. It has been shown in numerous studies that microwave remote sensing can provide spatially distributed patterns of surface soil moisture. New sensor generations as ENVISAT ASAR or RADARSAT allow for image acquisitions in different imaging modes and geometries. Imaging modes with large area coverage capabilities as the wide swath mode of ENVISAT ASAR are of special interest for practical applications in this context. The paper presents a semiempirical soil moisture inversion scheme for ENVISAT ASAR data. Different land cover types as well as mixed image pixels are taken into account in the soil moisture retrieval process. The inversion results are validated against in situ measurements and a sensitivity analysis of the model is conducted.