Study on algorithm of non-spherical symmetry inversion of ionospheric occultation data

The Abel inversion method, which is the traditional inversion of ionospheric occultation data, is based on a spherical symmetry of the ionospheric electron density distribution. However, the real ionosphere is not strictly spherical symmetry, which can cause errors in inversion process of ionospheric occultation data. To reduce the errors, we developed a new occultation inversion method, which used gradient information of IRI three dimensional ionospheric model, and combined the correct TEC (Total Electron Content) with the traditional inversion to reconstruct ionospheric electron density profile. In this paper, we introduce the new method and discuss the feasibility of the new method. The inversion results retrieved from the measurements data of COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) ionospheric occultation was compared with ionosonde data, and it shows that the new method was well coincident the ionospheric electron density profile.