Algorithms of inversion of Microlab-1 satellite data including effects of multipath propagation

The first results of the GPS/MET programme of sounding the Earth's atmosphere by means of a Low Earth Orbit satellite implemented with a Global Positioning System (GPS) receiver indicated that in the lower troposphere, the phase and amplitude of the signal received undergo strong oscillations. This effect is a consequence of multipath propagation resulting from the complicated structure of the atmospheric refractivity in the tropical regions. In this paper, we propose a method of processing of the phase measurements based on the theory of diffraction. The method was tested in processing GPS/MET radio soundings. Comparison of the reconstructed profiles of the temperature and humidity with those derived from radio soundings and extracted from the NMC Global Atmospheric Circulation Model indicates validity of the method proposed.