Acoustical time-reversal signal processing : new developments and applications

Abstract

This dissertation focuses on new developments and applications of timereversal

(TR) signal processing techniques for acoustic waves in the case of multiple

input channels. It is well known that the acoustic wave equation in a non-dissipative

medium contains a second-order time-derivative operator, which in turn is invariant

under a TR operation. Therefore, the TR is a novel technique that can employ backpropagation

of the wave to focus energy onto a specific location in space and time.

This is because back-propagated waves can retrace all of the complex paths such as

reflection, refraction and multiple scattering that they underwent during the forward

propagation. Thus, it results in highly focusing onto the initial source location. Based

on this property, there has been a strong interest in the application of TR techniques

in a broader topic of the acoustic field. Thus, the motivation of our dissertation is to

develop new algorithms based on the TR technique for applying in some important

topics of the acoustic field, including acoustic focusing, acoustic detection and

localization, acoustic inverse scattering as well as stereophonic acoustic echo

cancellation.