Abstract: After emission of an acoustic pulse, having a first duration, from a given location, acoustic signals coming from the location are gathered through a multi-scattering medium on an array of transducers and recorded, for a second duration greater by at least one order of magnitude than the first duration. Return signals obtained by temporal inversion and amplification of the signals gathered during the second duration are emitted back from said transducers toward the multiscattering medium in order to focus acoustic energy to the location while providing temporal compression of the focussed acoustic energy.
Type:
Grant
Filed:
December 13, 2000
Date of Patent:
December 20, 2005
Assignee:
Societe pour les Applications du Retournement Temporel
Abstract: After emission of an acoustic pulse, having a first duration, from a given location, acoustic signals coming from the location are gathered through a multi-scattering medium on an array of transducers and recorded, for a second duration greater by at least one order of magnitude than the first duration. Return signals obtained by temporal inversion and amplification of the signals gathered during the second duration are emitted back from said transducers toward the multiscattering medium in order to focus acoustic energy to the location while providing temporal compression of the focussed acoustic energy.
Type:
Application
Filed:
December 13, 2000
Publication date:
May 24, 2001
Applicant:
SOCIETE POUR LES APPLICATIONS DU RETOURNEMENT TEMPOREL
Abstract: Public announcements are made in a space using n speakers after having determined the impulse response hij(t) between a plurality of calibration points j belonging to the space and each speaker i. To transmit an information-bearing acoustic signal S(t) through at least one target area in the space in which announcements are to be made, each speaker i is made to transmit a signal (a), where j is an index representing calibration points in the target area.
Type:
Grant
Filed:
January 9, 1998
Date of Patent:
March 6, 2001
Assignee:
Societe pour les Applications du Retournement Temporel