The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Measurement of Spatial Coherence of Active Acoustic Sensor Array Signal

능동 음향센서 배열신호의 공간 상관성 측정

  • Received : 2012.04.03
  • Accepted : 2012.05.02
  • Published : 2012.05.31
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Abstract

Active acoustic array signal was measured in the East Sea and the South sea and spatial coherence was analyzed. The measurement of ambient noise, target reflection signal, sea surface backscattering signals took place including environmental measurements of sea wind, and vertical temperature profiles. The spatial coherence of ambient noise was lower than that of target reflection signal in the South Sea. The spatial coherence of target reflection signal was above 0.5 over all array length. The spatial coherence of sea surface backscattering signal was higher in high incident angle. The maximum non-dimensional array length was 3.0 ($26^{\circ}$) and 3.5 ($32^{\circ}$) to have spatial coherence above 0.5 in the East Sea. To find a design criteria for array configuration and array performance, more measurements of temporal and spatial coherence will be needed continuously in the future.

동해와 남해에서 능동 음향센서 배열 신호를 측정하고, 신호의 공간 상관성을 분석하였다. 주변소음, 표적신호, 해수면과 후방산란 신호, 해상풍, 수직 수온을 25시간 동안 동시에 관측하였다. 남해 측정에서는 분석결과로 부터 주변소음의 공간 상관성이 표적신호 보다 매우 낮고, 표적신호는 전체 음향센서에서 0.5 이상의 상관성을 보였다. 동해 측정에서는 해수면 잔향 신호의 공간 상관성은 해수면 입사각이 클때 높고, 상관성이 0.5이상인 무차원화된 배열의 최대길이는 26도의 입사각에서 3.0, 32도의 입사각에서 3.5였다. 배열센서의 형상과 배열성능을 결정하는 기준이 되는 공간 상관성 파악을 위해서는 향후에 다양한 시공간 변동을 포함한 지속적인 관측이 필요하다.

Keywords

References

  1. R. O. Nielsen, Sonar Signal Processing, Artech House, Boston, pp. 51-94, 1991.
  2. T. C. Yang, "Measurements of Spatial Coherence, Beamforming Gain and Diversity Gain for Underwater Acoustic Communications," OCEANS, 2005.
  3. T. C. Yang, "Measurements of temporal coherence of sound transmissions through shallow water," J. Acoust. Soc. Am., vol. 120, no. 5, pp. 2595-2614, 2006. https://doi.org/10.1121/1.2345910
  4. P. Nielsen, M. Siderius, "Broadband acoustic signal variability in two typical shallow-water regions," Impact of Littoral Environmental Variability on Acoustic Prediction and Sonar Performance, Kluwer, pp. 237- 244, 2002.
  5. R. Headricket, J. Lynch, J. Kemp, A. Newhall, K. Heydt, J. Apel, M. Badiey, C. S. Chiu, S. Finette, M. Orr, B. Paswwark, A. Turgot, S. Wolf, and D. Tielbuerger, "Acoustic normal mode fluctuation statistics in the 1995 SWARM internal wave scattering experiment," J. Acoust. Soc. Am., vol. 107, pp. 201-220, 2000. https://doi.org/10.1121/1.428563
  6. J. S. Park, S. Kim, Y. N. Na, Y. G. Kim, T. Oh, and J. Na, "Measurement of Horizontal Coherence Using Line Array in Shallow Water," J. Acoust. Soc. Kor., vol. 22, no. 2E, pp. 78-86, 2003.
  7. W. Carey et al, "Mid-Frequency Measurements of Array Signal and Noise Characteristics," IEEE J. Oceanic Eng., vol. 22, no. 3, pp. 548-565, 1997. https://doi.org/10.1109/48.611147
  8. 박정수, 김형록, 나영남, 김영규, 최지웅, "중주파수 배열신호의 시간 상관성 측정," 한국음향학회 춘계학술발표대회, 2010.
  9. 박정수, 김형록, 나영남, 김영규, 최지웅, "중주파수 해수면 후방산란의 공간 상관성 측정," 한국음향학회 춘계학술발표대회, 2011.
  10. H. Kim, A Study on the internal waves off the East Coast of Korea, Doctoral dissertation, Seoul National University, 2001.
  11. Y. Na, M. Jurng, and T. Shim, "Interference of Acoustic Signals Due to Internal Waves in Shallow Water," J. Acoust. Soc. Kor., vol. 18, no. 3E, pp. 9-20, 1999.
  12. Y. Na, Y. Kim, J, Park, E. Kim, J, Choi, "Considering of environmental factors affecting the detection of underwater acoustic signals in the continental regions of the East Coast Sea of Korea," J. Acoust. Soc. Kor., vol. 20, no. 2E, pp. 30-45, 2001.
  13. R. J. Urick, Principles of Underwater Sound 3rd ed, McGraw-Hill, New York, pp. 262-271, 1983.
  14. R. P. Chapman, J. H. Harris, "Surface Backscattering strengths Measured with Explosive Sound Sources," J. Acoust. Soc. Am., vol. 34, no. 10E, pp. 1592, 1962. https://doi.org/10.1121/1.1909057

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