CHARACTERIZATION OF A WEAKLY SCATTERING MEDIUM FROM ITS SIMULATED SCATTERING PATTERN

摘要

Characterization of a scattering medium from its scattering pattern will be of interest in microwave remote sensing. In this paper, an approach has been outlined for simulating the scattering from a weakly scattering random medium and then using this simulated pattern to carry out a characterization of the medium. The scattering medium under consideration is an ensemble of sparsely distributed randomly oriented dielectric discs. The method of moments is applied to compute the bistatic scattering pattern of the ensemble. In this method an integral equation is formulated in terms of the induced current distribution. From this integral equation the impedance matrix is obtained by expanding the volume current distribution in terms of a subdomain basis function. From the obtained current distribution, the scattered field from the particular disc can be found by applying the far field approximation. Using this as a basis, the bistatic scattering pattern of the medium can be found by vector addition of the fields from all discs. Using the bistatic power pattern the spatial domain Fourier transform is found. It has been shown that this spatial Fourier transform is indicative of the autocorrelation of the equivalent planar current distribution in the scattering layer. The peak to peak separation in this autocorrelation function gives an estimate of the effective separation between adjacent discs in the scattering layer.