Microwave Imaging of 3D Dielectric Structures by Means of a Newton-CG Method in lp Spaces

Abstract

An increasing number of practical applications of three-dimensional microwave imaging require accurate and efficient inversion techniques. In this context, a full-wave 3D inverse-scattering method, aimed at characterizing dielectric targets, is described in this paper. In particular, the inversion approach has a Newton-based structure, in which the internal linear solver is a conjugate gradient-like algorithm in lp spaces. The presented results, which include the inversion of both numerical and experimental scattered-field data obtained in the presence of homogeneous and inhomogeneous targets, validate the reconstruction capabilities of the proposed technique.

An Overview of Microwave Imaging for Breast Tumor Detection

“…Here the vectorial nature of the fields has to be tackled. 3D forward models and inversion methods implemented within the contrast source inversion framework have been reported in 2019 like Multi-Task Bayesian Compressive Sensing (MT-BCS) [95], Twofold Subspace-based Optimization Method (TSOM) [96], 3D Electrical-Property Tomography (3D-EPT) [97], Newton-CG Method in l p Spaces [98], etc. Development of direct 3D models helps in more accurate modeling and imaging.…”

Application of Whale Optimization Algorithm to Inverse Scattering of an Imperfect Conductor with Corners

“…In equation (10), η 0 is the intrinsic impedance, H (2) 0 (•) is the zero-order Hankel function of the second kind and J S (•) is the z-directed surface current density. Note that the notation "prime" indicates the source.…”

“…Inverse scattering means to reconstruct the shape or the electrical parameter distribution of an unknown scatterer by using the scattering data or the wave propagation model [1]. Basically, the reconstruction of a target's information is associated with the solution of an inverse problem, which is nonlinear and typically ill-posed [2]. e inverse scattering plays a very important role in different branches of science such as medical tomography, nondestructive testing, object detection, geophysics, ground penetrating radars, remote sensing, atmospheric science, and optics.…”

An Experimental Ultrasound System for Qualitative Tomographic Imaging

“…Thus, these approaches, known as full wave inversion methods, allow quantitative recoveries but are characterized by a higher computational cost than diffraction tomography. Most of these latter inverse scattering techniques are iterative and include the method of alternating variables (also known as iterative Born method, [ 50 ]), the Newton-type methods (or distorted Born iterative method, [ 51 , 52 , 53 ]) and conjugate gradient methods [ 54 , 55 , 56 , 57 , 58 ], among which the contrast source inversion is a notable example [ 49 ]. Nevertheless, other iterative algebraic methods can be adopted, such as Kaczmarz’s method, which successively refines the current estimate by performing orthogonal projections on hyperplanes related to a matrix operator [ 59 ], or eigenfunction methods, which rely on the eigenfunctions of the far-field operator relating an incident plane wave from a certain angle to the far-field scattering behaviour observed at another angle [ 60 ].…”