HORIZONTAL PARABOLIC EQUATION SOLUTION OF RADIOWAVE PROPAGATION PROBLEMS ON LARGE DOMAINS

The modeling of radiowave propagation in the troposphere often involve s field-strength calculations in very large domains, for which the usu al parabolic equation techniques become prohibitively expensive. The h orizontal parabolic equation method (HPE) provides a rigorous and effi cient full-wave solution for this type of problem, taking advantage of the fact that refractive index perturbations in the troposphere are u sually confined to a limited portion of the integration domain. Above the height where the medium becomes standard, Fourier and Laplace tran sform techniques are used to compute the field on a given horizontal, with convolution kernels based on exponential or Airy functions. The f ield on the initial horizontal may be obtained by any available method . The environment below the initial height may be range-dependent and include terrain variations. Substantial computing gains in both memory requirements and execution time are obtained. The method has been val idated by comparison to the standard vertical PE.