Evaluation of the Tau-Omega Model for Passive Microwave Soil Moisture Retrieval Using SMAPEx Datasets

Abstract

The parameters used for passive soil moisture retrieval algorithms reported in the literature encompass a wide range, leading to a large uncertainty in the applicability of those values. This paper presents an evaluation of the proposed parameterizations of the tau-omega model from 1) the soil moisture active passive (SMAP) algorithm theoretical basis document (ATBD) for global condition and 2) calibrated parameters from the National Airborne Field Experiment (NAFE'05) for Australian conditions, with special focus on the vegetation parameter b and roughness parameter H-{R}. This study uses airborne L-band data and field observations from the SMAP experiments conducted in south-eastern Austra..