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Resolution estimation for time reversal and imaging in random media

Special Events

Speaker: Chrysoula Tsogka, Stanford University
Location: 693 Kerr
Start time: Wed, Jan 21 2004, 4:10PM

An array of transducers receives the signals emitted by a localized source in a scattering acoustic medium. The received signals can be used, either in a time-reversal (TR) process in order to refocus acoustic energy back onto the source, or in an imaging (IM) process in order to localize the source position. In (TR) the signals are time-reversed and emitted into the physical medium whereas in (IM) the time-reversed signals are emitted in a fictitious homogeneous medium. We study the resolution obtained by these two processes and we show that multiple-scattering enhances the resolution in (TR) while it impedes the identification of the source location in (IM). A robust procedure for estimating the resolution gain and loss in (TR) and (IM) respectively will be presented.