S.Y. Belonogov, V.G. Gavrilenko, M.V. Kotelnikova, V.A. Yashnov

The multiple scattering of incoherent waves on a rough surface with a smooth large scale in comparison with wavelength gentle irregularities is considered. The problem is solved by numerical statistical simulation by the Monte-Carlo method, modified to account for scattering and diffraction of surface irregularities. In the case where the effects of shadowing and diffraction is weak, the results are consistent with the well-known from the publications. Emphasis is placed on the occasion of the grazing wave propagation. It is shown that shadowing leads to a significant decrease in the average energy density at the observation point. Found that the diffraction of waves has a significant impact, it leads to the significant increases the energy density with increasing wavelength due to diffraction wave penetration into the geometric shadow region. This gives rise to a qualitatively new dependence of energy on the distance between the source and observation point. The developed algorithm makes it possible to calculate also the angular distribution of received power in the horizontal plane. It is shown that the attenuation of waves due to shading leads to a drastic narrowing of the angular distribution.