SURFACE REFLECTION AT LOW-ANGLE PROPAGATION

A new derivation of the ground-reflection coefficient based on rough-s urface scattering theory is proposed to predict surface mechanism effe cts on both overwater and overland microwave line-of-sight links. A de tailed model of diffused scattering is constructed which agrees in par t with available experimental data and monostatic radar measurements. The model allows one to take into account the effects of antenna direc tivity, refraction by superrefractive layers, and various types of veg etation cover, Using this model, it is shown that atmospheric and surf ace mechanisms cannot be dissociated in estimating the ground refectio n coefficient and that, on terrestrial links, it is necessary to intro duce any forests as part of the terrain profile to estimate as accurat ely as possible the specular and the scattering reflection coefficient s.