Simultaneous inversion of permittivity and conductivity employing a nonperturbative a

摘要

We present a new inversion algorithm for the simultaneous reconstruction of permittivity and conductivity that recasts the nonlinear inversion as the solution of a coupled set of linear equations. The algorithm is iterative and proceeds through the minimization of two cost functions. At the initial step, the data is matched through the reconstruction of the radiating or minimum- norm scattering currents; subsequent steps refine the nonradiating scattering currents and the material properties inside the scatterer. We give recipes for constructing basis functions for the nonradiating components of the scattering currents. The method is illustrated through the reconstruction of a large contrast square cylinder from multiple-source measurements at a single frequency.