Bayesian combined active/passive (B-CAP) soil moisture retrieval algorithm: A rigorous retrieval scheme for SMAP mission

On-going and near-future Synthetic Aperture Radar (SAR) satellite missions are expected to provide meaningful and timely information about soil condition over vast agricultural lands such as those of the mid-western United States (corn-belt) and of Argentina (Pampas Plain), leading to actual economic benefits regarding to seeding dates, irrigation strategies and crop yield forecasting. NASA's Soil Moisture Active and Passive (SMAP) [1] and Argentinean SAOCOM (www.conae.gov.ar) missions have been specifically designed to develop surface soil moisture products. These missions will exploit microwave radar at L-band (λ = 23cm) as sensing wavelength, which demonstrated to be less sensitive to residue cover over soil's surface and to be more accurate on retrieving soil moisture than other bands.