| abstract |
Method for ultrasonic characterization of a medium comprising a step of generating a series of incident ultrasonic waves, a step of generating an experimental reflection matrix R ui (t) defined between the emission base ( i ) in input and a reception base ( u ) at the output, a step of determining a focused reflection matrix RFoc(r in , r out , δt) of the medium between a virtual input transducer (TV in ) calculated from 'an input focus of the experimental reflection matrix and an output virtual transducer (TV out ) calculated from an output focus of the experimental reflection matrix, the responses of the output virtual transducer (TV out ) being taken at a time instant shifted by an additional delay δt with respect to a time instant of the responses of the virtual input transducer (TV in ). |