Singular system analysis of the inversion of microwave radiometric data: applications to biological temperature retrieval

This paper refers mainly to the inversion of microwave radiometric data for the determination of temperature distributions in the human body. The analysis is restricted to a simple one-dimensional stratified model and special attention is devoted to a skin-fat-muscle structure (SFM) and to a muscle-bone-muscle structure (MBM). In both cases the technique of singular system analysis is applied to the corresponding integral equation in order to quantify the information content of the data. Numerical computations indicate that the information content is much greater in the MBM than in the SFM case, as one can guess from qualitative physical considerations. The results of some numerical inversions are also presented in order to assess the effectiveness and the practicability of the mathematical technique.