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Published on: February 12, 2014
The time-reversal operator with virtual transducers: application to far-field aberration correction
Jean-Luc Robert1, Mathias Fink
1Philips Research North America, Briarcliff Manor, New York 10510, USA.
The Journal of the Acoustical Society of America
|February 12, 2009
Summary
The focused decomposition of the time-reversal operator (FDORT) method offers a new perspective on wave propagation by using virtual transducers. This technique simplifies aberration correction by repositioning virtual transducers.
Area of Science:
- Acoustics
- Wave physics
- Signal processing
Background:
- The decomposition of the time-reversal operator (DORT) is a detection and focusing technique utilizing transmit-receive transducer arrays.
- DORT enables the extraction of Green's functions for scatterers within a medium.
Purpose of the Study:
- To interpret the focused decomposition of the time-reversal operator (FDORT) method.
- To demonstrate FDORT's capability to provide different perspectives of scatterers by repositioning virtual transducers.
- To explore FDORT's application in aberration measurement and correction.
Main Methods:
- Interpreting FDORT as a time-reversal operator decomposition between physical and virtual transducer arrays.
- Analyzing transmit and receive singular vectors in relation to Green's functions.
- Investigating the impact of virtual transducer positioning on problem simplification.
Main Results:
- FDORT can be viewed as a decomposition between physical and virtual transducer arrays located at focal points.
- Receive singular vectors represent scatterer Green's functions in the physical array; transmit singular vectors represent them in the virtual array.
- Repositioning virtual transducers offers variable viewpoints and can simplify complex wave propagation problems.
Conclusions:
- The FDORT method provides a flexible framework for analyzing wave phenomena by introducing virtual transducer arrays.
- FDORT simplifies aberration correction, particularly in phase screen models, by transforming far-field problems into near-field ones through strategic virtual transducer placement.
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