The Study Of Spatial Match Filter By Time Reversal Mirror

Ocean is underwater acoustic channel propagate signal from source to receiver. It is important for signal processor to know how to compensate for aberrations caused by inhomogeneity in the propagation medium. Time reversal (TR) is a unique self-adaptive focusing technique developed from phase conjugation using in nonlinear optics and ultrasonic fields. It can avoid imaging aberration of inhomogeneous media in acoustic and realize self-adaptive focusing without the prior knowledge of the media and the transducer.In this paper, we reviewed development of TRM technique. The focusing or the resolution of a TRM can be analyzed by theory and simulation. In the end, we introduce several main applications of a time reversal mirror and some new methods with TRM.Time resolution and spatial resolution of TRM relate to many parameters, such as waveguide geometry, sound-speed profiles, reflectivity and attenuation in the ocean, shape of probe signal, frequency of probe signal, duration of probe signal, integration time for time-reversal signal.Area for the application of a time reversal mirror is very extensive. There are the destruction of kidney and gallbladder stones in the human body, detection of cracks and defects within materials of various shapes, long-range communication and looking for mines.