Soil moisture mapping in a semi-arid region, based on ASAR/Wide Swath satellite data

摘要

In this paper, an operational algorithm is proposed for the mapping of surface moisture over a site in North Africa. A change detection approach is applied, using 160 Envisat ASAR Wide Swath images acquired over a 7-year period. Parameterization of this algorithm is considered for three classes of vegetation cover density (NDVI0.25, 0.25NDVI0.5 and NDVI>0.5), retrieved from SPOT-VGT decadal images. A relative soil moisture index, ranging between 0 and 1, is proposed for each date, with a resolution of 1 km. The retrieved soil moistures are validated by means of ground measurements, as well as ERS and ASCAT soil moisture products.