Microwave Imaging for Highly-Anisotropic Objects Based on Gauss-Newton Minimization Method

Abstract

Highly-anisotropic objects are reconstructed by microwave imaging in the integral equation approach. The volume integral equations (VIEs) are used to describe the interaction between the microwave and objects and inverse scattering VIEs (ISVIEs) and forward scattering VIEs (FSVIEs) are alternatively and iteratively solved based on the distorted Born iterative method (DBIM) until the solution converges. The convergent solution of permittivity or permeability in the imaging domain can reveal the imaging of unknown objects. The FSVIEs are solved by a Nyström method which is more suitable for solving inverse problem than the popular method of moments (MoM) due to its unique merits. Since the objects are highly anisotropic, the Gauss-Newton minimization method (GNMM) with a multiplicative regularization scheme (MRS) is employed to solve the ISVIEs so that the numerical experiments can be minimized for determining the regularization parameter. A numerical example is provided to illustrate the proposed approach and its good performance has been proved.