Acoustical Holography — A Comparison with Phased Array Sonar

  • P. N. Keating


The primary difference between phased-array sonar and acoustical holography lies only in the order in which the temporal and spatial processing operations are carried out. It is shown that this difference indirectly leads to an advantage for holography in terms of either signal-tonoise performance or reduced processing complexity in many types of application. The holographic approach has an important signal-to-noise advantage over scanned phasedarray systems because of parallel processing. Compared with multibeam sonar, the holographic spatial processing of data obtained from uniform arrays can be carried out with fewer operations than phased-array parallel beam-forming via adders and tapped shift registers because of the CooleyTukey algorithm. A significant reduction in processing operations due to data reduction in holography, especially for active systems, is also possible.


Spatial Processing DIMUS System Uniform Array Object Field Holographic System 
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.


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  1. 1.
    See, for example, H. G. Frey, “High Resolutions Sonar Technology,” Vol. II, p. 43, Classified Report No. 69-R-NRC:MAC:2027.Google Scholar
  2. 2.
    See, for example, H. R. Farrah, E. Marom, and R. K. Mueller, p. 173, Acoustical Holography, Vol. 2, Ed. by A. F. Metherell and L. Larmore (Springer Science+Business Media New York, 1970); R. K. Mueller, Proc. IEEE, 59, 1319 (1971).Google Scholar
  3. 3.
    For the purposes of this discussion, we define phasedarray systems as those in which the spatial processing (e.g., beam-forming) is carried out before the temporal processing, and holographic systems as those in which the reverse is true, the reconstruction being carried out last.Google Scholar
  4. 4.
    See, for example, P. N. Keating, R. F. Koppelmann, R. K. Mueller, and R. F. Steinberg (to be published).Google Scholar
  5. 5.
    M. O. Fein and E. S. Eby, Naval Underwater Sound Laboratory Technical Memo No. 2242–173–69 (July 1969).Google Scholar
  6. 6.
    V. C. Anderson, J. Acoust. Soc. Am., 32, 867 (1960).ADSCrossRefGoogle Scholar
  7. 7.
    P. Rudnick, J. Acoust. Soc. Am., 32, 871 (1960).ADSCrossRefGoogle Scholar
  8. 8.
    In actual fact, the original DIMUS approach used only one-bit words whereas current holographic systems use 8–12 bits for each word. However, one-bit words can be used for holography [see, for example, W. J. Dallas and A. W. Lohmann, Acoustical Holography, Vol. 4, p. 463, Ed., G. Wade (Springer Science+Business Media New York, 1972)] with the same drop in performance as in DIMUS. Alternatively, a comparison with current holographic systems should involve an “improved” DIMUS with 8–12 bit digitization and the corresponding reduction in quantization “noise”.Google Scholar
  9. 9.
    J. W. Cooley and J. W. Tukey, Math. Comput., 19, 297 (1965).MathSciNetzbMATHCrossRefGoogle Scholar
  10. 10.
    B. Gold and C. M. Rader, Digital Processing of Signals (McGraw-Hill, New York, 1969).zbMATHGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1974

Authors and Affiliations

  • P. N. Keating
    • 1
  1. 1.Bendix Research LaboratoriesSouthfieldUSA

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