A TERRAIN PARABOLIC EQUATION MODEL FOR PROPAGATION IN THE TROPOSPHERE

A method to model tropospheric radiowave propagation over land in the presence of range-dependent refractivity is presented. The Terrain Parabolic Equation Model (TPEM), is based on the split-step Fourier algorithm to solve the parabolic wave equation, which has been shown to be numerically efficient. Comparisons between TPEM, other terrain models (SEKE, GTD, FDPEM), and experimental data show predominantly excellent agreement. TPEM is also compared to results from an experiment in the Arizona desert in which range-dependent refractive conditions were measured. Although horizontal polarization is used in the implementation of the model, vertical polarization is also discussed.