SIGNAL-TO-NOISE RATIO AND AUTOCORRELATION FUNCTION OF THE IMAGE INTENSITY IN COHERENT SYSTEMS - SUB-RAYLEIGH AND SUPER-RAYLEIGH CONDITIONS

This paper is devoted to developing a scattering model for coherent im aging systems. It describes the statistical properties of the image in tensity due to the distribution of scatterers on a subresolution scale , The roughness of the scatterers' strength, the randomness of the spa tial architecture, and the birth-death process of the scattering cente rs are considered. Two parameters of the image intensity are examined for the characterization of the scattering medium: 1) the signal-to-no ise ratio (SNR), which permits the distinguishing of sub-Rayleigh (SNR < 1) from super-Rayleigh (SNR > 1) conditions and 2) the correlation coefficient, These parameters permit the estimation of the roughness a nd randomness degrees of the structure. The model is then extended to account for specular effects and applied to sea clutter. A quantitativ e treatment of the spatial and temporal correlation characteristics, b ased on a physical understanding of the underlying process, is derived , Experimental results are presented to validate the model.