Propagation of centimeter and millimeter radio waves at small grazing angles: The model of multiple screen diffraction

Specific features of the microwave propagation over a disturbed sea surface at small grazing angles are studied numerically in the approximation of multiple Fresnel diffraction by semiplanes. We consider two cases: 1) the case of very small grazing angles and low altitudes of the observation points over the sea surface and 2) the case of moderately small grazing angles where the asymptotic approximation of the Fresnel integral is applicable. It is shown that such a model permits one to explain, in particular, the high field-intensity levels and fluctuation characteristics observed at observation-point altitudes comparable with the sea-wave height. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 8, pp. 700–710, August 2008.