Time-reversal methods for acousto-elastic equations and applications

Time reversal (TR) is a subject of very active research. The principle is to take advantage of the reversibility of wave propagation phenomena, for example in acous- tics, elastic or electromagnetism in an unknown medium, to back-propagate signals to the sources that emitted them. In a previous paper [1], we introduced a time-reversed method for acoustic equation. In this paper, our aim is to extend this approach to elastodynam- ics equations. As the application we have in mind are concerned with ultrasound-based elasticity imaging methods, we consider both elastic and acousto-elastic systems of equa- tions. We stress that our method does not rely on any a priori knowledge of the physical properties of the inclusion