Non-spherical Symmetric Of Ionospheric Occultation Inversion

A constellation of six satellites, called COSMIC, was launched on 15 April 2006 from Vandenberg Air Force Base, California. And lots of ionospheric occultation data were provided from the COSMIC satellites. In the Earth's ionosphere, radio wave propagation prone happen reflection, scattering, refraction and absorption. Ionospheric disturbances and irregularities can affect short-wave communications, satellite communications and satellite navigation. Therefore, there is very important to search the ionosphere.This thesis discusses the traditional inversion of ionospheric occultation and other inversion methods. The main works can be summarized as following:1. This thesis briefly describes the development of the Ionospheric Radio Occultation (IRO) technique, the structure and the current situation of the ionospheric.2. The relative total electron content TEC is obtained through the combination of COSMIC radio occultation ionosphreic measurements L1 and L2 phase; The TEC data are then calibrated by non-occultation observation data on the auxiliary side to remove portion of TEC above the LEO orbit altitude; The electron density profile can be retrieved from TEC by Abel integral transformation, with a spherically symmetric assumption of electron density and an approximation of signal straight-line propagation.3. The Abel inversion based on a spherical symmetry of the ionospheric electron density distribution is a traditional method for inversion of ionospheric occultation. However, the real ionosphere is not strictly spherical symmetry, which can cause error in inversion process of ionospheric occultation data. To reduce the error, this thesis discusses the other inversion methods, focusing on the feasibility of these methods.4. This thesis introduces the ourselves researching software of the inversion of ionospheric occultation, including input files and out files.5. Make a brief summary of the results.