Theory of iterative time reversal acoustic mirrors.

Numerical Simulation of Acoustic Time Reversal Mirrors

We study the time reversal phenomenon in a homogeneous and non-dissipative medium containing sound-hard obstacles. We propose two mathematical models of time reversal mirrors in the frequency domain. The first one takes into account the interactions between the mirror and the obstacles. The second one provides an approximation of these interactions. We prove, in both cases, that the time revers...

Selective Acoustic Focusing Using Time-Harmonic Reversal Mirrors

A mathematical study of the focusing properties of acoustic fields obtained by a time-reversal process is presented. The case of time-harmonic waves propagating in a nondissipative medium containing sound-soft obstacles is considered. In this context, the so-called D.O.R.T. method (decomposition of the time-reversal operator in French) was recently proposed to achieve selective focusing by comp...

Ultrasonic Time Reversal Mirrors

For more than ten years, time reversal techniques have been developed in many different fields of applications including detection of defects in solids, underwater acoustics, room acoustics and also ultrasound medical imaging and therapy. The essential property that makes time reversed acoustics possible is that the underlying physical process of wave propagation would be unchanged if time were...

Time - reversal mirrors

On time reversal mirrors

The concept of time reversal (TR) of scalar wave is reexamined from basic principles. Five different time reversal mirrors (TRM) are introduced and their relations are analyzed. For the boundary behavior, it is shown that for paraxial wave only the monopole TR scheme satisfies the exact boundary condition while for the spherical wave only the MD-mode TR scheme satisfies the exact boundary condi...