MUSIC electromagnetic imaging with enhanced resolution for small inclusions

Abstract

This paper investigates the influence of the test dipole on the resolution of the multiple signal classification (MUSIC) imaging method applied to the electromagnetic inverse scattering problem of determining the locations of a collection of small objects embedded in a known background medium. Based on the analysis of the induced electric dipoles in eigenstates, an algorithm is proposed to determine the test dipole that generates a pseudo-spectrum with enhanced resolution. The amplitudes in three directions of the optimal test dipole are not necessarily in phase, i.e., the optimal test dipole may not correspond to a physical direction in the real three-dimensional space. In addition, the proposed test-dipole-searching algorithm is able to deal with some special scenarios, due to the shapes and materials of objects, to which the standard MUSIC does not apply.

Interpretation of linear sampling method in terms of induced multipoles

“…This enhancement in the reconstruction is similar to[15], where the enhancement in resolution has been demonstrated for MUSIC.IV. DISCUSSION: DIPOLE RADIATION AS THE IMAGING FUNCTION (INSTEAD OF MONOPOLE)…”

A Novel Study on Direct Sampling Method for Imaging Multiple Targets

“…Motivated from this, non-iterative techniques for retrieving the location of such inhomogeneities have been investigated. Those include the MUltiple SIgnal Classification (MUSIC) algorithm [5,6,7], the linear sampling method [8,9,10], and Kirchhoff and subspace migrations [11,12,13]. Although these techniques are confirmed to be fast, stable, and effective, they still require observations from a significant number of directions of the incident and scattered field or far-field data to obtain an acceptable result.…”

Appearance of inaccurate results in the MUSIC algorithm with inappropriate wavenumber

“…Among them, MUltiple SIgnal Classification (MUSIC)-type algorithm is applied to the problem for detecting small inhomogeneities or crack-like defects, refer to [1,[3][4][5]8,14,16,17,21] and references therein. However, for obtaining a good result, the value of applied wavenumber must be known.…”