利用GPS/MET与CHAMP掩星资料反演地球中性大气参数的比较

Comparison of Earth’s Neutral Atmospheric Parameters Inversed with GPS/MET Data and CHAMP Data

采用Abel积分反演算法 ,在干大气模式下 ,分别针对GPS/MET与CHAMP特定掩星事件的Level2数据进行处理 ,得到了相应的折射指数与大气参数廓线。分别将反演结果与UCAR和GFZ公布的结果进行比较 ,证明了反演算法的正确性与通用性。分析了两个温度反演结果都存在系统误差和CHAMP温度反演结果误差较大的原因 。

The same inversion method, which does not take the effect of water vapor into account, was applied to processing level2 data of certain occultation event of GPS/MET experiment and CHAMP mission. The profiles of refractivity and neutral atmospheric parameters has been compared with level3 data provided by UCAR and GFZ, respectively. The temperature and pressure profiles are also compared with those from UCAR and GFZ, respectively. Although both pressure profiles are in accordance with the corresponding Level3 data, the temperature profile from GPS/MET is better than that from GFZ. After analyzing the systematic error which exists in the temperature profiles retrieved in both cases, this paper points out that the remnant ionospheric errors and the constrains of the temperature on the upper bound are two factors for it. When retrieving atmospheric parameters profiles from refractivity profiles, to get temperature profile from CHAMP data which is more accordant with the result of GFZ, we need to constrain the temperature on the upper bound with different methods.