Analysis of ionospheric electron density distribution from GPS/MET occultations

The authors present results from analysis of GPS/MET occultation data obtained from the University Corporation for Atmospheric Research database. They have used high-rate occultation data to study the performance of an earlier 4D ionospheric electron content model-obtained tomographically with the use of the GPS constellation-with satisfactory results. In addition, they have processed UCAR level-one medium-rate occultation data by using the GIPSY package to obtain aligned phases. Under the assumption of local spherical symmetry, this phase information has been processed to yield ray-path bending angles through Doppler-shift analysis, which have then been used to yield profiles of electronic density via the Abel transform. These profiles give important information for preparing future tomographic work, although the limitations imposed by the working assumptions in this approach cannot be ignored