PROPAGATION OF ACOUSTIC WAVES THROUGH A SPATIALLY FLUCTUATING MEDIUM: THEORETICAL STUDY OF THE PHYSICAL PHENOMENA
| Autor: | Real, Gaultier, Cristol, Xavier, Sessarego, Jean-Pierre, Fattaccioli, Dominique |
|---|---|
| Přispěvatelé: | Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Thales Underwater Systems (Thalès) (TUS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre Technique des Systemes Navals (CTSN), DGA, Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), REAL, Gaultier |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph]
[SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph] De-coherence Fluctuations Dimensionless Analysis [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing Tank Experiments |
| Zdroj: | UACE2014, 2nd International Conference and Exhibition on Underwater Acoustics UACE2014, 2nd International Conference and Exhibition on Underwater Acoustics, Jun 2014, Rhodes, Greece |
| Popis: | International audience; The authors focus on the effects of phenomena, such as linear internal waves, that are responsible for fluctuations of the depth-dependent sound speed profile and, hence, induce distortions of the resulting acoustic pressure field and degradation of the associated sonar performances. The main goal of this study is to develop a scaled experiment configuration able to provide some results representative of this kind of distortions. To do so, a theoretical study of the phenomenon has first been carried out: we obtained an expression for the standard parabolic equation applied to the Fourier transform of the moments of order 2 and 4 in 3D medium. Various simulation programs were developed and used for the following purposes: validating or discarding some relationships given by Flatté through his classical dimensionless analysis (ΛΦ plane); tracing rays through an acoustic lens featuring a plane face and a randomly rough face and propagating an acoustic wave through the same object in order to anticipate for the shape of the distorted pressure field, including diffraction effects. We were able both theoretically and experimentally to induce acoustic scattering that mimics, at reduced scale and frequencies around 2MHz, the correlation properties and the corresponding array performance that would be observed at sea, after propagation through a linear internal wave field, or reflection on a rough sea surface. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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