INVERSION OF GPS OCCULTATION MEASUREMENTS USING FRESNEL DIFFRACTION THEORY

Occultation data from the GPS/MET experiment are inverted to temperatu re profiles of the neutral atmosphere of the Earth using the Fresnel i nversion technique. The technique is not limited in resolution by diff raction effects thus a good vertical resolution is achieved. In the de rivation a thin screen approximation is used. The influence of this ap proximation on the results is discussed. The results obtained using th e Fresnel inversion is compared to results obtained using the traditio nal geometrical optics inversion approach and to numerical weather pre diction data.