ROUGH-SURFACE SCATTERING RESULTS BASED ON BANDPASS AUTOCORRELATION FORMS

Surface height autocorrelation forms such as Gaussian and exponential are often used in studies of near-normal incidence rough surface scattering. Such models require the existence of a constant, or dc, value in the spectrum. This investigation examines the consequences of autocorrelation forms which correspond to spectral processes that are essentially bandpass in nature. One such process is that of ocean wind waves; that is, the spectral components do not extend down to zero frequency. The physical optics backscatter theory is reexamined relative to such autocorrelation functions. Experimental results obtained from a wavetank are compared to the autocorrelation model used in the analysis. This analysis indicates that “Gaussian correlation length” or mean-square slope is not an appropriate parameter for narrow-band conditions, and that significant slope is a more relevant parameter. Inherent in the deep-phase assumption is some form of slope dependency. The analysis given, and variants thereof, can be used to provide insight into the physical effects of separate spectral components and of spectral directionality. © 1990, IEEE.