|Development of Time-Reversal Method for Detecting Multiple Moving Targets Behind the Wall
Takeshi Nanri (Kyushu University)
|There are many imaging systems in the world for see-through the wall or cancer detection such as MRI for medical imaging. However the current technologies are not cheap nor not available everywhere. One of the cheap alternatives to such expensive systems is microwave imaging using the Time Reversal (TR) method which was first introduced in acoustics. TR has found applications in various disciplines ranging from non-destructive testing, underwater communications and medicine. TR has also been studied for Ground Penetrating Radar (GPR) as well as Through the Wall Imaging (TWI). The TR method with some super-resolution techniques such as Decomposition Of the Time-Reversal Operator (DORT in its French acronym) or MUltiple SIgnal Classification (MUSIC) requires more than 150 Fast Fourier Transform and more than 20000 singular value decomposition for a very small imaging system which consists of 13 antenna elements. Therefore the current approach is far from the real-time system due to the long computational time. Furthermore there is a high demand on the detection of multiple moving targets but the work in this field is scarce. The detection of multiple moving targets behind the wall is the one of the most challenging scenarios in through-the-wall microwave imaging. So far Fumie Costen at University of Manchester has developed the spatio-temporal windowing for the differential MDM (multi-static data matrix) for time reversal algorithm to detect multiple moving objects in a simple canonical case. This project will develop and verify an algorithm to detect the multiple moving targets with high computational efficiency.
|研究紹介ポスター ／ 最終報告書