ANALYSIS OF IONOSPHERIC ELECTRON-DENSITY DISTRIBUTION FROM GPS MET OCCULTATIONS/

In this paper, we present results from analysis of GPS/MET occultation data obtained from the University Corporation for Atmospheric Researc h database, We have used high-rate occultation data to study the perfo rmance of an earlier 4D ionospheric electron content model-obtained to mographically with the use of the GPS constellation-with satisfactory results. In addition,we have processed UCAR level-one medium-rate occu ltation data by using the GIPSY package to obtain aligned phases, Unde r the assumption of local spherical symmetry, this phase information h as been processed to yield ray-path bending angles through Doppler-shi ft analysis, which have then been used to yield profiles of electronic density via the Abel transform, These profiles give important informa tion for preparing future tomographic work, although the limitations i mposed by the working assumptions in this approach cannot be ignored.