An integral equation approach to UHF coverage estimation

The boundary value integral equation with moment method solution is a well known method for the study of electromagnetic problems. This elegant and simple method is often referred to as a low frequency technique due to its excessive use of computer resources for problems whose dimensions are large compared to that of the wavelength of the radiation source. In this paper we propose a method for calculating the field strength above undulating terrain by means of an approximation to the electric field integral equation (EFIE) such that the amount of memory needed is O(n) and the numerical complexity is O(n log n), where n is the number of integration points along the scatterer. The approximation involves describing the Green´s function as a perturbation series with respect to the arclength variable