Soil Moisture Retrieval Using an L-Band Synthetic Aperture Radiometer During the Soil Moisture Experiments 2003 (SMEX03) and 2004 (SMEX04)

Soil moisture retrievals made using data from the airborne L-band microwave radiometer, 2D-STAR, over a wide range of land cover types are presented. The 2D-STAR was flown over six regional-scale sites during Soil Moisture Experiments in 2003 and 2004. Four sites located in Alabama, Georgia, Arizona, and Sonora were selected for this work. Land cover types included bare soil, bare soil with gravelly surface, shrub, crop field, and forest. Topographic conditions varied from flat or gently rolling plains to high-relief hilly or mountainous area. Results indicate fairly good soil moisture retrieval performance of the 2D-STAR over the various land cover types and moisture conditions (overall RSME=0.22 m³/m³). The 2D-STAR also showed improved soil moisture retrieval over a C- and X-band microwave instrument (PSR-C/X) for densely vegetated areas and gravelly soil surfaces.