Parabolic Wave Equation Method Applied to the Tropospheric Ducting Propagation Problem: A Survey

A survey is made of one of the most widely used approximation methods in the wave propagation studies—the parabolic wave equation method—applied for the specific case of microwave propagation assessment under tropospheric ducting conditions. A brief review of the methods for tropospheric refractivity profiling, the average refractivity modeling, and the applicability of the often-assumed lateral homogeneity of the refractivity is given. The parabolic wave equation derivation and the numerical methods for solving it are summarized with special emphasis on transparent boundary conditions for the upper computational window boundary. Results are reported which illustrate the application of the finite element method and split-step Fourier-based solutions of parabolic wave equations for different cases of tropospheric ducts, concerning radar and communications links performance.