Parabolic equation modelling of propagation over irregular terrain

The author presents applications of a numerical solution of the wave equation for radiowave propagation over irregular terrain, based on the parabolic approximation to Maxwell´s equations. The novelty of the method resides in its ability to calculate signal strength when both the medium and the boundaries are allowed to have essentially arbitrary structures. It is a full-wave method which allows the modelling of wavefronts of arbitrary shapes, within the constraints of the PE approximation. The finite difference treatment of the air/ground boundary allows the representation of an arbitrary path profile as a sequence of linear segments. The method is valid at all ranges except in the near-field of the antenna, and there are no frequency constraints provided the propagation phenomena to be modelled take place within a few degrees of the horizontal