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

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.