Quick Search: Journal  Author  Title/Abstract  Vol./Year 

Jpn. J. Appl. Phys. 43 (2004) pp. 3163-3168  |Previous Article| |Next Article|  |Table of Contents|
|Full Text PDF (170K)| |Buy This Article|

Sound Pressure Fields Focused Using Biconcave Acoustic Lens for Normal Incidence

Toshiaki Nakamura, Yuji Sato, Tomoo Kamakura1 and Tetsuo Anada2

Department of Earth and Ocean Sciences, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686, Japan
1Department of Electronic Engineering, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu 182-8585, Japan
2Department of Electrical Engineering, Kanagawa University, 3-27 Rokkakubashi, Yokohama 221-8686, Japan

(Received November 26, 2003; revised February 3, 2004; accepted February 5, 2004; published May 28, 2004)

The underwater imaging sonar system with an acoustic lens is again receiving considerable attention because it does not require a complex beam-forming circuit. The lens system used in this type of sonar was designed by the ray theory or by a hybrid method of the ray and wave theories. In this report, a basic analysis was performed by an analytical method using a wave theory and by a numerical method using the parabolic equation (PE) method, to determine the convergent characteristics of a biconcave lens. The pressure field focused by the biconcave lens was measured in a water tank. The biconcave lens used in the experiment is made of acrylic resin with a radius of 20 cm and a radius of curvature of 20 cm. Measurements was conducted in a water tank at a frequency of 500 kHz. Sound pressure fields around the focal region measured by the experiments agreed well with the calculated ones by the analytical and PE methods.

URL: http://jjap.jsap.jp/link?JJAP/43/3163/
DOI: 10.1143/JJAP.43.3163
KEYWORDS:acoustic lens, biconcave lens, wave theory, PE method, imaging sonar


|Full Text PDF (170K)| |Buy This Article| Citation:

References | Citing Articles (12)

  1. S. Tsukioka, T. Aoki, H. Ochi, T. Shimura, T. Sawa, T. Nakamura, T. Anada, I. Kaihou and H. Noda: Jpn. J. Appl. Phys. 41 (2002) 3970[JSAP].
  2. E. Belcher, W. Hanot and J. Burch: Proc. 2002 Int. Symp. Underwater Technology (IEEE Oceanic Engineering Society, Tokyo, 2002) p. 187.
  3. Y. Tannaka and T. Koshikawa: J. Acoust. Soc. Am. 53 (1973) 590[AIP Scitation].
  4. K. Katakura, Y. Tannaka, M. Kobayashi and T. Koshikawa: J. Acoust. Soc. Jpn. 31 (1975) 716 [in Japanese].
  5. T. Kikuchi, M. Okujima and S. Takahashi: J. Marine Acoust. Soc. Jpn. 12 (1985) 40 [in Japanese].
  6. D. L. Folds: Underwater Acoustics and Signal Processing, ed. L. Bjørnø (D. Reidel Publishing Co., Dordrecht, 1981) p. 263.
  7. K. Fink: Master Thesis of Science in Electrical Engineering, Univ. Washington (1994).
  8. T. Kamakura, K. Aoki, T. Nakamura and H. Adachi: J. Marine Acoust. Soc. Jpn. 30 (2003) 48 [in Japanese].
  9. T. Kamakura and T. Nakamura: Tech. Rep. IEICE US2002-40 (2002) 17.
  10. T. Tshuchiya, T. Anada, N. Endoh, T. Nakamura and I. Kaihou: Tech. Rep. IEICE US2001-33 (2001) 1.
  11. T. Anada, T. Tsuchiya, N. Endoh, I. Kaihou, T. Nakamura. T. Tsukioka, T. Aoki and I. Kaiho: Jpn. J. Appl. Phys. 41 (2002) 3509[JSAP].
  12. T. Kamakura, T. Ishiwata and K. Matsuda: J. Acoust. Soc. Am. 107 (2000) 3035[AIP Scitation].
  13. T. Kamakura, K. Aoki and T. Ishiwata: ACUSTICA Acta Acustica 86 (2000) 446.
  14. T. Kamakura, T. Ishiwata and K. Matsuda: J. Acoust. Soc. Am. 105 (1999) 3083[AIP Scitation].
  15. D. W. Peacman and H. H. Rachford: J. Soc. Ind. Appl. Math. 3 (1955) 28.
  16. D. Lee and M. H. Schultz: Numerical Ocean Acoustic Propagation in Three Dimensions (World Scientific Publishing, Singapore, 1995) p. 58.
|TOP|  |Previous Article| |Next Article|  |Table of Contents| |JJAP Home|
Copyright © 2013 The Japan Society of Applied Physics
Contact Information