Space–Frequency Ultrawideband Time-Reversal Imaging

Abstract

We introduce time-reversal ultrawideband (UWB) imaging functionals based on the simultaneous utilization of spatial and UWB frequency data acquired by limited-aspect antenna arrays. The targets are discrete scatterers embedded in homogeneous or continuous random inhomogeneous media. Singular value decomposition is applied to space-frequency multistatic scattering data matrices indexed by sensor location and frequency data, and the resulting singular values and vectors are employed to construct time-domain excitation signals for UWB imaging of the embedded scatterer(s) via synthetic backpropagation (reverse migration). Spatial information needed for focusing on the embedded scatterer(s) is provided by either the left singular vectors or the eigenvectors of the space-space multistatic data matrices. The resulting UWB imaging functionals can yield statistical stability in random media. Index Terms-Decompositionof the time reversal (TR) operator (DORT), imaging, Multiple Signal Classification (MUSIC), TR.

Imaging and tracking of targets in clutter using differential time-reversal techniques

“…Time-reversal (TR) techniques [7][8][9][10][11][12][13] have shown to be very useful for applications in remote sensing and imaging utilizing either acoustic/elastic waves [8,11] or electromagnetic waves [9,10,12,13]. These techniques exploit the time invariance of the wave equation in lossless media under TR [14,15].…”

Interferometry by Deconvolution of Multicomponent Multioffset GPR Data

“…For an overview of the theory of "seismic interferometry" or "Green's function retrieval" and its applications to passive as well as controlledsource data, we refer to a reprint book [3], which contains a large number of papers on this subject. Similarly, time-reversal techniques are well known in several branches of science and technology, and they are still actively being researched [4]- [9]. Model-driven time-reversal imaging techniques can account for energy dissipation by not only correcting for travel time delay but also for amplitude effects [10].…”

Interferometric Time Reversal Music for Small Scatterer Localization

“…Such a MUSIC version resolves some problems affecting time domain time reversal scheme without the need of further processing to compensate the arbitrary and frequency dependent phases which characterizes MDM eigenvectors [28]. Moreover, because it combines reconstructions obtained at different frequencies it is shown that this method is statistically stable [20].…”