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Inverse scattering of Hz waves using local shape-function imaging: A T-matrix formulation

✍ Scribed by Gregory P. Otto; Weng Cho Chew


Publisher
John Wiley and Sons
Year
1994
Tongue
English
Weight
596 KB
Volume
5
Category
Article
ISSN
0899-9457

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✦ Synopsis


Inverse scattering algorithms for H, polarized waves are scarce, due to the added difficulties of polarization charges. Nevertheless, the polarization charges cannot be ignored for 3D problems, as well as for 2D H, problems. This work aims to reconstruct arbitrary inhomogeneous dielectric objects from H, scattering data using a new formulation that abandons the standard integral equation model for a T-matrix model. This new algorithm, called local shape-function (LSF) imaging, is modified for dielectric objects with H, incident fields, where previously the LSF algorithm was applied to metallic objects with €, incident fields. The advantage of the LSF algorithm is This paper solves the inverse scattering problem for H , waves impinging on two-dimensional dielectric objects. This solution abandons the standard integral equation model for a T-matrix model, called local shape-function (LSF) imaging. With this technique, larger objects or higher contrasts can be resolved compared to the Born-type iterative methods. The improvement arises because the model has a better approximation for the internal field. Specifically, the inverse mapping has a better internal depolarization model, which is more important for reconstructing large dielectric contrasts.

a more accurate modeling of the induced interfacial polarization charges. For comparison, the H7 distorted Born iterative method

11-BORN INVERSE SCATTERING METHOD

usins integral equations IS shown to be valid only for small contrasts, while the LSF algorithm converges for much larger dielectric con-traStS. @ 1994 John Wiley 8 Sons, Inc

We will consider the geometry of Fig. 1, consisting of an unknown arbitrary dielectric object E(X, Y ) , a TE incident field H I ( x , y ) , and receivers located in the far field of the object which can measure the scattered magnetic field H : ( x , , y , ) at several points i = 1,2;. . , M . For time har-