Scattering of a diffracted field by turbulent pulsations of the refractive index of the troposphere

With reference to long-range tropospheric propagation, the single-scattering approximation is used to assess the intensity of a transhorizon signal determined by field scattering in a volume located in a region of geometric shadow relative to the source and receiver. The dependence of this intensity on wavelength, distance, and altitude of the antenna is investigated. The expressions obtained are in better qualitative agreement with experimental data than the Booker-Gordon theory. The absolute levels of a signal scattered in the shaded region of the troposphere are generally lower than those predicted by this theory; however, when highly directional antennas are used, these levels can be comparable to those predicted by the theory.