A Bayesian approach for a SAC-D/aquarius soil moisture product

In this work, several retrieval algorithms were implemented to retrieve soil moisture (sm) and optical depth (τ) from Aquarius/SAC-D observations. Currently used sm retrieval algorithms (H- and V-pol Single Channel Algorithm, SCAH and SCAV; Microwave Polarization Difference Algorithm, MPDA) were computed over Pampas Plains, Argentina. The methodology of a novel Bayesian algorithm developed is also presented, and its results are contrasted with the previous algorithms. Finally, performance metrics for each algorithms were derived using SMOS Level-2 sm and τ as benchmark products. The new Bayesian approach provide the sm retrieval algorithm that exhibited the lowest ubRMSE (0.115m
³
/m
³
), though very close to USDA SCA and SCAV ubRMSE (0.116m
³
/m
³
). Nevertheless, some improvements are discussed in Section 4 that might increase significantly the Bayesian algorithm performance.