Research on the GPS signal scattering and propagation in the tropospheric ducts

In this paper, the method of moment (MoM) is used to investigate the characteristics of the GPS (Global Positioning System) signal scattering from the rough sea surface under low grazing incidence, and then on the basis of the results, the GPS signal could be received as the initial field by the improved Discrete Mixed Fourier Transform algorithm (DMFT) method to study the propagation characteristics in the tropo-spheric ducts. The advantages of MoM are shown the validity in computing the EM scattering at low grazing incident angle and also shown by the comparison of the Bistatic Scattering Coefficient (BSC) with MoM and Kirchhoff Approximation (KA). Finally, the propagation properties of GPS scattering signal in the evaporation ducts with different evaporation duct heights and elevation angles of GPS are discussed by the improved discrete mixed Fourier transform with taking into account the sea surface roughness.