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Grenoble Images Parole Signal Automatique |
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Grenoble Images Parole Signal Automatique |
| HAL: hal-00678358, version 1 |
| DOI: 10.4236/oja.2012.21001 |
| Detailed view |  Export this paper |
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| Open Journal of Acoustics 2, 1 (2012) 1-11 |
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| Modelling of High-Frequency Roughness Scattering from Various Rough Surfaces through the Small Slope Approximation of First Order |
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| Virginie Jaud 1Cedric Gervaise 2 |
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| (2012-03-12) |
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| The first-order small slope approximation is applied to model the scattering strength from a rough surface in underwater acoustics to account for seafloor for high frequencies from 10 kHz to hundreds of kilohertz. Emphasis is placed on simulating the response from two-dimensional anisotropic rough surfaces. Several rough surfaces are described based on structure functions such as the particular sandy ripples shape. The scattering strength is predicted by the small slope approximation and is first compared to a well known bistatic method, interpolating the Kirchhoff approximation and the small perturbations model, assuming that the rough interface is isotropic. Results obtained from the two different mod-els are similar and show a higher level in the specular direction than in the other directions. For an isotropic surface, changing the propagation plane gives similar results. Then, SSA, which lets us adapt the structure function of the roughness straight away, is tested trough several anisotropic surfaces. In a longitudinal direction of ripples, the scatter-ing strength is mostly in the specular direction, whereas in the transversal direction of ripples, the scattering strength prediction shows high values for different angular directions. Thus the scattering strength is spread in a very different way strictly related to the particular features of the ripples. Combine our results, indicates the importance of taking into account the anisotropy of a surface in a scattering prediction process, taking into account the positions of the emitter and of the receiver which are naturally significant when predicting scattering strength. |
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| 1: | Pôle STIC [Brest] (STIC) |
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ENSTA Bretagne |
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| 2: | Grenoble Images Parole Signal Automatique (GIPSA-lab) |
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CNRS : UMR5216 – Université Joseph Fourier - Grenoble I – Université Pierre-Mendès-France - Grenoble II – Université Stendhal - Grenoble III – Institut Polytechnique de Grenoble - Grenoble Institute of Technology |
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| 3: | Service Hydrographique et Océanographique de la Marine (SHOM) |
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Ministère de la Défense |
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| 4: | Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC) |
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CNRS : UMR3192 – Université de Bretagne Occidentale [UBO] – Université de Bretagne Sud – Institut Mines-Télécom – Télécom Bretagne – PRES Université Européenne de Bretagne [UEB] – Institut Supérieur des Sciences et Technologies de Brest (ISSTB) |
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| AP SIGMAPHY Lab-STICC_ENSTAB_MOM_PIM REMS |
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| Subject | : | Engineering Sciences/Acoustics Physics/Mechanics/Acoustics |
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| Anisotropy – Roughness – Scattering – Small Slope Approximation |
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| hal-00678358, version 1 | |
| http://hal-ensta-bretagne.archives-ouvertes.fr/hal-00678358 | |
| oai:hal-ensta-bretagne.archives-ouvertes.fr:hal-00678358 | |
| From: Annick Billon-Coat | |
| Submitted on: Monday, 12 March 2012 15:37:27 | |
| Updated on: Wednesday, 3 April 2013 19:36:31 | |
