A Model Analysis Using a Combined Active/Passive Microwave Remote Sensing Approach for Soil Moisture Retrieval

Abstract

This study develops a new algorithm for estimating bare surface soil moisture using combined active/passive microwave remote sensing on the basis of TRMM(Tropical Rainfall Measuring Mission).To accurately estimate bare surface soil moisture,the algorithm simultaneously uses a precipitation radar(PR) and microwave imager(TMI) for observation.In this paper,through an analysis of the numerically simulated surface backscattering and emissivity database by Advanced Integral Equation Model(AIEM) with a wide range of soil moisture and surface roughness conditions,the authors have found that the surface roughness parameter has an important impact on both backscattering coefficient and emissivity.Based on the simulated database by AIEM,the authors use theoretical model(Geometrical Optical Model) and semi-empirical model(Qp Model) through the analysis of surface roughness as well as TRMM/PR and TMI data to develop the algorithm for estimating bare surface soil moisture.