Terrain-based propagation model for rural area-an integral equation approach

A terrain-based propagation model for vertically polarized radio waves is described, based on the field integral equation for a smooth surface. The model is simplified from a 3D integral equation model to a one-dimensional integral equation by assuming that the surface is magnetically perfectly conducting (a soft surface) with no transverse variations. By assuming no back scattering, the integral equation is turned into a simple integral. The method is tested numerically with known solutions. The integral equation model is also applied to actual terrain profiles at four frequencies (144, 435, 970, 1900 MHz), and the results are compared with results from the Hata model and measurements. The standard deviation (STD) of the error is a growing function of frequency, from 3 to 9 dB.>