The technique of bistatic RCS estimate is proposed for sea and terrain clutter with application of monostatic RCS measured data for small grazing angles that can be applied in centimeter and millimeter bands of radio waves. The models of bistatic scattering are analyzed including the model of small perturbations, facet model and theorem of equivalence; the limitations of these models are discussed. The features of bistatic scattering near the specular points (the forward scattering) are analyzed and estimates are carried out the RCS values for different terrain types.
In directions differing from quasi-specular one, the normalized bistatic RCS dependences on grazing angles and bistatic angle are obtained for different types of terrain and for sea at frequencies of 10.0 and 35.0 GHz. These data are founded at results of RCS measurements carried out by author for monostatic regime. The comparison of calculated results with experimental data available for bistatic radar was carried out. It is shown the good coincidence of these results. Thus, the proposed technique permits to evaluate the bistatic RCS using the data of monostatic measurements for small grazing angles at wide band of frequencies up to 95 GHz.