Abstract: To sound water vapor precisely in the atmosphere is essential for weather phenomenon research,global climate change research and numerical weather forecast.The main purpose of this paper is to develop an inverse model for atmospheric parameter profiles using radio occulation data.This paper demonstrates the deficiency of the old retrieval model and some atmospheric parameter profiles are obtained.Through the linear retrieval and using the ECMWF’S temperature,the new retrieval model is established,and some atmospheric parameter profiles are given.Then the author analyses the bug in the atmospheric parameter profiles;and finally,brings forward the next way to optimize the retrieval model.

Key words: space based GPS, retrieval, optimize