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university of Provence - Aix-Marseille I |  |
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university of Provence - Aix-Marseille I | |
| HAL: hal-00177246, version 1 |
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| Ultrasonics Symposium, Honolulu : United States (1990) |
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| Characterization of elastic shells by the use of the wavelet transform |
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| Ginette Saracco 1, 2, 3Philippe Guillemain 1 |
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| For the GDR 820 Ondelettes collaboration(s) |
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| (1990-12) |
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| This paper concerns the characterization of elastic targets immersed in a fluid and submitted to an acoustic impulse. Time-frequency methods have already been used in the case of scatterers of simple geometric shape. We have chosen the wavelet transform for its particular properties, such as linearity aand local analysis at Df/f=Cst. We have developped an algorithm based on the behavior of the phase of the transform, which enables us to extract modulation laws (related to the dispersion law of the phase velocity), even for close echoes. In the case of spherical elastic shells, we have applied this method on both experimental and computer-generated signals and have pointed out the good relation between theoretical and experimental results. |
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| 1: | Laboratoire de Mécanique et d'Acoustique (LMA) |
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CNRS : UPR7051 |
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| 2: | Géosciences Rennes (GR) |
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CNRS : UMR6118 – INSU – Centre Armoricain de Recherches en Environnement – Université de Rennes 1 |
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| 3: | Centre européen de recherche et d'enseignement de géosciences de l'environnement (CEREGE) |
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CNRS : UMR6635 – Institut de recherche pour le développement [IRD] – INSU – Université de Provence - Aix-Marseille I – Université Paul Cézanne - Aix-Marseille III |
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| Subject | : | Physics/Mechanics/Acoustics Engineering Sciences/Acoustics |
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| Complex wavelet transform – ridge – skeleton – frequency modulation laws – amplitude modulation laws – asymptotic wavelet – spectral line – scattering – elastic shells – stationary phase – phase and group velocity |
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| Attached file list to this document: | |||||
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| hal-00177246, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00177246 | |
| oai:hal.archives-ouvertes.fr:hal-00177246 | |
| From: Ginette Saracco | |
| Submitted on: Wednesday, 9 January 2008 02:10:32 | |
| Updated on: Wednesday, 9 January 2008 09:17:39 | |
