Surface reflection at low-angle propagation

A new derivation of the ground-reflection coefficient based on rough-surface scattering theory is proposed to predict surface mechanism effects on both overwater and overland microwave line-of-sight links. A detailed model of diffused scattering is constructed which agrees in part with available experimental data and monostatic radar measurements. The model allows one to take into account the effects of antenna directivity, refraction by superrefractive layers, and various types of vegetation cover. Using this model, it is shown that atmospheric and surface mechanisms cannot be dissociated in estimating the ground reflection coefficient and that, on terrestrial links, it is necessary to introduce any forests as part of the terrain profile to estimate as accurately as possible the specular and the scattering reflection coefficients