Ionospheric Tomography with GPS Data from CHAMP and SAC-C

Abel inversion offers a straightforward way to obtain the vertical distribution of electron density with low computational load. Nevertheless the treatment of the electron density above the LEO orbit must not be neglected, specially for satellites with very low orbit such as CHAMP. This work extends previous results obtained by inverting real GPS data from LEO data, coming from satellites such as CHAMP or SAC-C. In this work, the topside ionosphere is modelled using positive elevation data. To overcome the spherical symmetry assumption, occultations are processed with the aid of Vertical Total Electron Content, estimated from ground GPS data or models. The resulting electron density profiles are compared with external real data consisting basically on basic parameters or true-height vertical profiles obtained from ionosonde measurements.