Electromagnetic Time-Reversal Source Localization in Changing Media: Experiment and Analysis

Abstract

-An experimental study is performed on electromagnetic time reversal in highly scattering environments, with a particular focus on performance when environmental conditions change. In particular, we consider the case for which there is a mismatch between the Green's function used on the forward measurement and that used for time-reversal inversion. We examine the degradation in the time-reversal image with increasing media mismatch, and consider techniques that mitigate such degradation. The experimental results are also compared with theoretical predictions for time reversal in changing media, with good agreement observed.

Application of TRM in the Uwb Through Wall Radar

“…15(a) and (b) show the imaging results. It is clear that the observations are consistent with previous studies in [28,32]. A fair refocusing is observed at the target's location.…”

“…For concerning the image stability, we also investigate the TRM images for the case in which there is a mismatch between the walls associated with the forward and inverse phases of time reversal. The conclusions here are consistent with previous studies in [28,32]. This paper is organized as follows: we briefly provide in Section 2 the main principles of TRM technique.…”

“…Under some wave propagation mode (for instance, in the paraxial regime), refocusing in the high frequency is statistically stable, that is, independent of the realizations of the two media. Experimental studies of electromagnetic TRM [28] demonstrated a fair refocusing at the targets location in spite of media interchanging and a substantial deterioration of the TRM image as the media de-correlation increases.…”

“…Considering the features of the complex environment in TWR imaging, this communication induces the time reversal mirror (TRM) technique to TWR. The TRM has been demonstrated both theoretically and experimentally in an extensive set of ultrasonic and acoustic measurements [17][18][19][20][21][22][23], as well as in recent electromagnetic studies [24][25][26][27][28][29][30][31]. It can provide a high-resolution image in both spatial and temporal.…”

Evaluation of TRM in the Complex Through Wall Environment

“…TRM, which has been demonstrated both theoretically and experimentally in an extensive set of ultrasonic and acoustic literatures [14][15][16][17][18][19][20], as well as in recent electromagnetic studies [21][22][23][24][25][26][27][28], is widely regarded as a powerful tool for imaging, especially in the complex environment. [29] reported a preliminary application of TRM in UWB-TWRI.…”