Electromagnetic imaging based on the characteristic properties of the Rayleigh coefficient


  • S. K. Chaudhuri


In this paper, characteristic parameters of low-frequency scattered signal are analyzed for their dependence on the object's geometry, and specifically the Rayleigh coefficient is identified as a suitable quantity for the imaging and identification applications involving volume and size estimations. In order to recover the Rayleigh coefficient from the backscattered signals, an inverse scattering model is presented here, which is based on the time domain concepts of electromagnetic theory. Using the first five moment condition integrals, the returned pulse response is processed to recover the Rayleigh coefficient, and the next higher order nonzero coefficient of the power series expansion in k (wave number) of the object backscattering response. The Rayleigh coefficients thus recovered are related to the volume, elongation factor (eccentricity), and orientation of an equivalent spheroid by use of a nonlinear optimization algorithm. Numerical simulation of the scheme of this paper has been tested on different scatterers. The results of these simulations are presented.