DEVELOPMENT OF GEOPHYSICAL RETRIEVAL ALGORITHMS FOR THE MIMR

Results from a study concerning the feasibility of spaceborne microwave radiometry to retrieval of geophysical parameters are described. The study concentrates on the development of inversion techniques for multichannel spaceborne radiometers, especially the statistical inversion approach. The basic tool in this study was the developed simulation/inversion software. Especially, the applications of the planned MIMR instrument (Multi-Frequency Imaging Microwave Radiometer) are discussed. The employed inversion algorithms are 1) conventional algorithms for different applications and 2) the statistical inversion approach (maximum likelihood inverse solver). Comparisons between results from different inversion algorithms have also been carried out. The statistical inversion approach has been found to give promising parameter retrieval accuracies and is a potential tool to improve the operational use of passive spaceborne remote sensing. Additionally, sensitivity analysis of the radiometer apparent temperature to different geophysical parameters and the statistical behavior of the atmospheric transmissivity are presented.