| Presentation | 2008-08-29 A Basic Study of Focusing Characteristics of Acoustic Aplanatic Lens for Ambient Noise Imaging Kazuyoshi MORI, Hanako OGASAWARA, Toshiaki NAKAMURA, Yuji SATO, Takenobu TSUCHIYA, Tetsuo ANADA, Nobuyuki Endoh, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Much attention has been paid to the new idea of detecting objects by using ocean ambient noise. This concept is called ambient noise imaging (ANI). To design an ANI system, the authors analyzed the sound field focused by an acoustic lens system constructed with a single spherical biconcave lens using the Finite Difference Time Domain (FDTD) method and the reduced scale trial of one-fifth space in a water tank. These results showed that the lens with an aperture size of 2.0m has sufficient resolution for realizing the ANI system; for example, the beam width is 1 deg at 60kHz. In this study, we apply an aplanatic lens correcting spherical and comma aberrations to ANI system. The dependences of aperture size, source range and refraction index are surveyed by 2-D FDTD method. And the results of plane wave incidence are also analyzed by 3-D FDTD method. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Ambient Noise Imaging / Acoustic Lens / FDTD Method / Directional Resolution / Aplanatic Lens |
| Paper # | US2008-28 |
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| Committee | US |
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| Conference Date | 2008/8/22(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Ultrasonics (US) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Basic Study of Focusing Characteristics of Acoustic Aplanatic Lens for Ambient Noise Imaging |
| Sub Title (in English) | |
| Keyword(1) | Ambient Noise Imaging |
| Keyword(2) | Acoustic Lens |
| Keyword(3) | FDTD Method |
| Keyword(4) | Directional Resolution |
| Keyword(5) | Aplanatic Lens |
| 1st Author's Name | Kazuyoshi MORI |
| 1st Author's Affiliation | Department of Earth and Ocean Sciences, National Defense Academy() |
| 2nd Author's Name | Hanako OGASAWARA |
| 2nd Author's Affiliation | Department of Earth and Ocean Sciences, National Defense Academy |
| 3rd Author's Name | Toshiaki NAKAMURA |
| 3rd Author's Affiliation | Department of Earth and Ocean Sciences, National Defense Academy |
| 4th Author's Name | Yuji SATO |
| 4th Author's Affiliation | Graduate School of Systems and Information Engineering, University of Tsukuba |
| 5th Author's Name | Takenobu TSUCHIYA |
| 5th Author's Affiliation | Department of Electronics and Informatics Frontiers, Kanagawa University |
| 6th Author's Name | Tetsuo ANADA |
| 6th Author's Affiliation | Department of Electronics and Informatics Frontiers, Kanagawa University |
| 7th Author's Name | Nobuyuki Endoh |
| 7th Author's Affiliation | Department of Electronics and Informatics Frontiers, Kanagawa University |
| Date | 2008-08-29 |
| Paper # | US2008-28 |
| Volume (vol) | vol.108 |
| Number (no) | 196 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |