Semi-rough surface scattering and its fading effects for active microwave sensors

Ground scattering to a microwave incident wave is usually considered as a non-coherent process when the ground surface is rough in terms of wavelength. However, situations do exist where the composed field at the receiving antenna aperture is coherent when the ground surface is smooth or rough but with a non-uniformly distributed random phase. In this paper, the authors have calculated the coherent phenomenon and shown the fading effects exist for both nadir and off-nadir looking situations. To distinguish from conventional considerations, they introduced the semi-rough surface concept for the uniformly distributed random phase situations