Modelling of the propagation of GPS signals over the horizon

The propagation of GPS signals over the horizon is considered in this paper. Parabolic equation for the electromagnetic wave propagation with initial fields, absorbing boundary and polarization parameters are used in the modeling. Finite difference method is used to solve the equation with an improved new Hanning window function absorbing boundary model. The simulation results under the environments of sea surface based duct and evaporation duct are presented, and the calculated methods and results are elaborated.