Method and apparatus for acoustic examination using time reversal
US5428999A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1993 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Sep 24, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K2200/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for acoustic examination of a medium and detection of reflective targets includes a preliminary step of injecting a divergent sound beam into the medium from at least one transducer. Then the echo signals reflected by the medium and received by several transducers in an array are picked up. A time gate is used to select echoes coming from a particular zone of the medium. The echoes are stored, time-reversed and re-emitted. The signals newly reflected by the medium are stored and the time-reversal operation is repeated. After a final time reversal of rank 2n+1 (where n is a positive non-zero integer) over the full depth of the measurement time gate, the characteristics of the wavefront passing closest to the maxima of the signals are determined, advantageously in the form of a time distribution of the maxima. The characteristics can often be approximated with a polynomial law. An apparatus is disclosed for implementing the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.