The study of retrieval theory and methods from satellite remote sensing for meteorological parameters over Eastern Asia - Part II: ISPRM and VSPRM2

Based on the practice of improved simultaneous physical retrieval model (ISPRM), in the light of the functional analysis approach, the variational simultaneous physical retrieval model (VSPRM) has been developed. Its approximation of 1st degree is VSPRM1. which is identical with the ISPRM. Its approximation of 2nd degree is VSPRM2, more advanced than the VSPRM1. This paper has analyzed the function of VSPRM2, pointing out the potentiality od synergy retrieval of this model. Also, it has dealt with the problem of parameterization of water vapor's kernel functions and retrieval of water vapor remote sensing. Because of the characteristics of this strong ill-posed inverse problem, prior information must be used wisely in order to get the accurate calculation of radiance R. In the previous paper, we discussed how to build the best first guess field, the way to determine the P and to correct the calculation of radiance. In the paper, we continue discussing in depth about the calculation of transmittance the determination of surface parameters and the selection for an optimum combination of channels for the low-level soundings. The long-term experiment and comparison work unde operational environment have shown that the ISPRM is useful for retrieval of temperature and water vapor parameters over China including the Tibetan Plateau and it further proves the scientific nature of well-posed inverse theory.