Détection et localisation de cible en guide d'onde : application au concept de barrière acoustique à l'échelle du laboratoire

Christian Marandet 1
1 Laboratoire de Géophysique Interne et Tectonophysique
LGIT - Laboratoire de géophysique interne et tectonophysique
Abstract : This thesis demonstrates experimentally at the laboratory scale the detection and localization, in transmission, of a wavelength-sized target in a shallow ultrasonic waveguide between two source-receiver arrays in the framework of the acoustic barrier problem. Two coplanar arrays record in the time-domain the transfer matrix of the waveguide between each pair of source-receiver transducers. Invoking the reciprocity principle, a time-domain double-beam-forming algorithm is simultaneously performed on the source and receiver arrays. This array processing projects the multireverberated acoustic echoes into an equivalent set of eigenray, which are defined by their launch and arrival angles. Comparison is made between the amplitude of each eigenray without and with a target for detection in the waveguide. Localization is performed though inversion problem using all of the eigenrays extracted from double beamforming. The use of the diffraction-based sensitivity kernel for each eigenray provides both the localization and the signature of the target. Experimental results are shown in the presence of surface waves. The use of the acoustical feedback in frame of the acoustic barrier problem is also considered, for its extreme sensibility to medium variation.
Document type :
Theses
Earth Sciences. Université de Grenoble, 2011. French. <NNT : 2011GRENU032>


https://tel.archives-ouvertes.fr/tel-00680103
Contributor : ABES STAR <>
Submitted on : Saturday, March 17, 2012 - 4:28:18 PM
Last modification on : Wednesday, October 29, 2014 - 1:25:05 PM

File

manuscrit_marandet_christian_f...
fileSource_public_star

Identifiers

  • HAL Id : tel-00680103, version 1

Collections

STAR | OSUG | LGIT | IRD | INSU | UGA | IFSTTAR

Citation

Christian Marandet. Détection et localisation de cible en guide d'onde : application au concept de barrière acoustique à l'échelle du laboratoire. Earth Sciences. Université de Grenoble, 2011. French. <NNT : 2011GRENU032>. <tel-00680103>

Export

Share

Metrics

Consultation de
la notice

455

Téléchargement du document

49