Imaging of Layer Inhomogeneity in Stratified Environment via a Tomographic Reconstruction

Abstract

This paper presents a tomographic reconstruction algorithm based on inverse of a set of integral equations relating to Fourier transform of backscattered field data with sought object function at each excitation frequency. Probed structure is a part of a multilayered material half-space containing, in one layer, a cylindrical object of arbitrary cross-section and electrical properties. Both the material and geometrical parameters of the half-space are known. The structure is irradiated by an incident plane wave (TM case). The backscattered field is measured at the probing line over the half-space. As a result, an N×N system of linear equations is derived for each integral equation. A regularized solution for the object function is obtained based on the assumption that the object function is a frequency independent value. This assumption allows coupling of the systems of linear equations at each frequency. We then address experimental results on microwave imaging of different objects for various probed structures.

Keywords:

• microwaves
• multilayer structure
• tomographic reconstruction
• regularization

Acknowledgment

The authors would like to thank members of ILHT, Viktor N. Stepanyuk, and Aysun Cevirme for their cooperation.