Bispectral Passive Holographic Imaging System

  • Takuso Sato
  • Kimio Sasaki
  • Yoichi Nakamura
  • Masaharu Nonaka

Abstract

A new ultrasonic and/or acoustical imaging system, which uses non-Gaussian random signals and cross- and auto-bispectral analysis is presented in this paper. It consists of a fixed point receiver on a hologram plane and a scanning receiver on the same plane. The non-Gaussian signals radiated from the object and detected by these receivers are analyzed. By calculating their cross- and autobispectra and taking the ratio between them the holographic information, that is the distribution of the amplitudes and phases of a certain wave length is derived from these results over the plane. The following points will be presented; i) principle, ii) theoretical developments, iii) computer simulations and the outline of a prototype of a practical system for the diagnosis of machine system at audio frequency region. Mechanical noises, such. as the noises from engines of a submarine, can be regarded as non-Gaussian signals and ambiguous noises surrounding circumstances, such as the ocean tide, may be regarded as Gaussian noises, so this method is especially effective when it is used under fairly large additive Gaussian noises. Because bispectrum of Gaussian noises vanishes completely they do not disturb the hologram when it is obtained by the bispectral analysis. Although the fundamental parts of this method have been submitted in various journals (Refs. 1, and 2), comprehensive discussions will be given in this article.

Keywords

Ocean Tide Random Signal Power Spectral Analysis Point Noise Bispectral Analysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Sato and K. Sasaki, “Bispectral Holography”, J. Acoust. Soc. (accepted for publication).Google Scholar
  2. 2.
    K. Sasaki, T. Sato and Y. Nakamura, “Holographic Passive Sonar’ IEEE Trans.. Sonics and Ultrasonics (accepted for publication).Google Scholar
  3. 3.
    V. H. MacDonald and P. 34. Shuliheis, J. Acoust. Soc. Am. 46, Part 1, 37 (1968).Google Scholar
  4. 4.
    P. Heimdal and F. Bryn, in Signal Processing, J. W. R. Griffiths and P. L. Stocklin Eds. ( Academic Press, New York, 1973 ) P. 261.Google Scholar
  5. 5.
    W. S. Liggett, Jr, ibid., P. 327Google Scholar
  6. 6.
    W. R. Hahn and S. A. Tretter, IEEE Trans. Inf, Theory IT-19, 608 (1973).Google Scholar
  7. 7.
    W. R. Hann, J. Acoust. Soc. Am. 58, 201 (1975)Google Scholar
  8. 8.
    S. Ueha, M. Fujinami, K. Umesawa and J. Tsujiuchi, Appt. Opt. 14, 1478 (1975).ADSCrossRefGoogle Scholar
  9. 9.
    D. R. Brillinger and M. Rosenblatt, in Advanced Seminar on Spectral Analysis of Time Series, B. Harris Ed. (wiley, New York, 1967) P.`153.Google Scholar
  10. 10.
    A. Blanc-Lapiere and R. Fortet, Theory of Random Functions (Gordon and Breach, New York, 1965 ) Vol. IL, 8.’Google Scholar
  11. 11.
    B. P. Hildebrand and R. B. Brenden, An Introduction to Acoustical Holography (Plenum, New York, 1972 ) Chap. 4.Google Scholar
  12. 12.
    K. Kiriyama and T. Sato, Bull. of Tokyo Institute of Technology 112, 9 (1972).Google Scholar
  13. 13.
    K. ‘Sasaki, T. Sato and Y. Yamashita,,J. Sound Vib. 40 (1), 139 (1975).ADSCrossRefMATHGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • Takuso Sato
    • 1
  • Kimio Sasaki
    • 1
  • Yoichi Nakamura
    • 1
  • Masaharu Nonaka
    • 1
  1. 1.Faculty of Science and EngineeringTokyo Institute of TechnologyNagatsuda, Midori-Ku, Yokohama 227Japan

Personalised recommendations