Effect of irregular terrain on the ground wave field at 10 mhz

The propagation of the ground wave field over a smooth geometrically irregular terrain is considered. The calculations of the modulus of the ground wave field attenuation function over model and real radio paths are presented. The field strength measurements over irregular terrain at a frequency of 10 MHz are performed. The attenuation function calculations on a relief path are performed using the Hufford’s integral equation. The numerical solution of the integral equation is applicable to relief paths with elevation differences commensurate with the wavelength. Comparison of the calculations with measurements on a real mountainous path at a frequency of 10 MHz showed satisfactory agreement of the results. It is shown that the applicability of the integral equation method for calculating the attenuation function is due to the location of the geometric inhomogeneity from the transmitter at a distance of no closer than five integration steps.