The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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A Study on the Characteristics of Underwater Sound Transmission by Short-term Variation of Sound Speed Profiles in Shallow-Water Channel with Thermocline

수온약층이 존재하는 천해역에서 단기간 음속구조 변화에 따른 음향 신호 전달 변동에 관한 연구

  • 정동영 (과학기술연합대학원대학교) ;
  • 김시문 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 변성훈 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 임용곤 (한국해양과학기술원 부설 선박해양플랜트연구소)
  • Received : 2014.09.15
  • Accepted : 2014.11.21
  • Published : 2015.01.31
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Abstract

Underwater acoustic channel impulse responses (CIR) are influenced by sound speed profile (SSP), and the variation of CIR has significant effects on the performance of underwater acoustic communication systems. A significant change of SSP can occur within a short period, which must be considered during the design of underwater acoustic modems. This paper statistically analyzes the effect of the variation of SSP on the long-range acoustic signal propagation in shallow-water with thermocline using numerical modeling based on the data acquired from JACE13 experiment near Jeju island. The analysis result shows that CIR changes variously according to the SSP and the depth of the transmitter and receiver. We also found that when the transmitter and receiver are deeper, the variation of sound wave propagation pattern is smaller and signal level becomes higher. All CIR obtained in this study show that a series of bottom reflections due to downward refraction and small bottom loss in the shallow water with thermocline can be very important factor for long-range signal transmission and the performance of underwater acoustic communication system in time varying ocean environment can be very sensitive to the variation of SSP even for a short period of time.

수중음향 전달채널의 임펄스 응답(Channel Impulse Response: CIR)은 음속구조(Sound Speed Profile: SSP)의 영향을 받으며, 채널 임펄스 응답의 변화는 수중음향통신 시스템의 성능에 중요한 영향을 미친다. 음속분포의 변화는 단기간 내에서도 나타날 수 있으며, 수중음향 모뎀 설계 시 반드시 고려되어야 한다. 이 논문은 2013년도에 제주도 동방해역에서 수행된 JACE13에서 취득된 데이터를 기반으로 음선전달 수치해석을 통해 단기간 동안 시간에 따라 변화하는 음속구조가 음향 신호 전달에 미치는 영향을 통계적으로 분석한 결과를 제시한다. 분석결과 송 수신기 수심별로 채널 임펄스 응답의 변화가 다양하게 나타나며, 송 수신기 수심이 깊을수록 음속구조의 변동에 따른 음향신호 전달 양상의 변화는 작아지고, 신호 준위가 높게 나타난다. 이 연구에서의 다양한 거리, 송, 수신기 수심에 따라 얻어진 채널 임펄스 응답 추정 결과는 수온약층에서의 하방굴절로 인한 연속된 해저면 반사와 작은 해저면 반사손실이 장거리 신호 전파에 중요한 요인이 될 수 있음을 보여주며, 시변동성을 갖는 해양환경에서의 수중 음향 통신은 시간에 따라서 성능이 충분히 달라질 수 있다는 것을 보여준다.

Keywords

References

  1. X, Lurton, An Introduction to Underwater Acoustics: Principles and Applications (Springer Praxis Publishing, London, 2002), pp. 2-3.
  2. A. C. Singer, J. K. Nelson, and S. S. Kozat, "Signal processing for underwater acoustic communications," in IEEE Communications Magazine, 90-96 (2009).
  3. M. Stojanovic and J. Preisig, "Underwater acoustic communication channels: propagation models and statistical characterization," IEEE Communications Magazine 47, 84-89 (2009).
  4. D. B. Kilfoyle and A. B. Baggeroer, "The state of the art in underwater acoustic telemetry," IEEE 25, 4-27 (2000).
  5. A. C. Singer, J. K. Nelson, and S. S. Kozat, "Signal processing for underwater acoustic communications," in IEEE Communications Magazine, 90-96 (2009).
  6. M. Stojanovic, J. A. Catipovic, and J. G. Proakis, "Phasecoherent digital communications for underwater acoustic channels," IEEE J. Ocean. Eng. 19, 100-111 (1994). https://doi.org/10.1109/48.289455
  7. H. S. Kim, D. H. Choi, J. P. Seo, J. H. Chung, and S. Kim, "The experimental verification of adaptive equalizers with phase estimator in the East Sea" (in Korean), J. Acoust. Soc. Kr. 29, 229-236 (2010).
  8. G. F. Edelmann, T. Akal, W. S. Hodgkiss, S. Kim, W. A. Kuperman, and H. C. Song, "An initial demonstration of underwater acoustic communication using time reversal," IEEE J. Ocean. Eng. 27, 602-609 (2002). https://doi.org/10.1109/JOE.2002.1040942
  9. H. C. Song, W. S. Hodkiss, W. A. Kuperman, W. J. Higley, K. Raghukumar, T. Akal, and M. Stevenson, "Spatial diversity in passive time reversal communications," J. Acoust. Soc. Am. 120, 2067-2076 (2006). https://doi.org/10.1121/1.2338286
  10. S. M. Kim, S. H. Byun, S. G. Kim, S. J. Kim, D. J. Kim, and Y. K. Lim, "Analysis of underwater acoustic channel around jeju island using 6kHz and 12kHz signals" (in Korean), J. Acoust. Soc. Kr. Suppl. 1(s) 33, 132-134 (2014).
  11. M. Siderius, M. B. Porter, P. Hursky, V. McDonald, and t. K. Group, "Effects of ocean thermocline variability on noncoherent underwater acoustic communications," J. Acoust. Soc. Am. 121, 1895-1908 (2007). https://doi.org/10.1121/1.2436630
  12. Y. N. Na and T. B. Shim, "The effects of the variations of oceanographic environments on propagation loss in the east coast sea off pohang, korea" (in Korean), J. Acoust. Soc. Kr. 9, 62-73 (1990).
  13. Y. N. Na, T. B. Shim, and S. I. Kim, "Propagation loss variability due to hourly variations of underwater sound speed profiles in the korea strait," J. Acoust. Soc. Am. 14, 5-13 (1995).
  14. B. C. Kim, B. K. Choi, "A study on seasonal variation of propagation loss in the yellow sea using broadband source of low frequency,"J. Acoust. Soc. Am. 21, 213-220 (2002).
  15. M. B. Porter. The bellhop manual and user's guide: preliminary draft, Heat, Light, and Sound Research, Inc, 2011.
  16. T. C. Yang, "Properties of underwater acoustic communication channels in shallow water," J. Acoust. Soc. Am. 131, 129-145 (2012). https://doi.org/10.1121/1.3664053
  17. J. M. Joo, Adaptive use of geoacoustic data In shallow water (in Korean), (M.S. thesis,University of Hanyang, 2007).
  18. S. H. Byun, S. M. Kim, and Y. K. Lim,"A study on longrange sound transmission in shallow-water channel with thermocline" (in Korean), J. Acoust. Soc. Kr. 33, 273-281 (2014). https://doi.org/10.7776/ASK.2014.33.5.273
  19. E. Y. T. Kuo, "Sea surface scattering and propagation loss: review, update and new predictions," IEEE J. Oceanic Eng. 13, 229-234 (1988). https://doi.org/10.1109/48.9235
  20. A. D. Jones, A. J. Duncan, D. W. Bartel, A. Zinoviev, and A. Maggi, "Recent developments in modelling acoustic reflection loss at the rough ocean surface," in Proc. ACOUSTICS 2011, 1-8 (2011).
  21. H. W. Marsh, M. Schulkin, and S. G. Kneale, "Scattering of underwater sound by the sea surface," J. Acoust. Soc. Am. 33, 334-340 (1961). https://doi.org/10.1121/1.1908656
  22. P. Beckmann and A. Spizzichino, The Scattering of Electromagnetic waves from Rough Surfaces (Pergamon Press, Oxford, 1963), pp. 398-417.
  23. R. B. Lauer, "The Acoustic model evaluation committee (AMEC) reports," NORDA Rep. 36, 1982.
  24. R. W. McGirr, "An analysis of surface-duct propagation loss modeling in SHARPS," NORDA Rep. 209, 1990.
  25. M. A. Ainslie, "Effect of wind-generated bubbles on fixed range acoustic attenuation in shallow water at 1 - 4 kHz," J. Acoust. Soc. Am. 118, 3513-3523 (2005). https://doi.org/10.1121/1.2114527
  26. A. D. Jones, J.Sendt, A.J. Duncan, P.A. Clarke, and A. Maggi, "Modelling the acoustic reflection loss at the rough ocean surface," in Proc. ACOUSTICS 2009, Adelaide, Australia (2009).
  27. H. Medwin and C. S. Clay, Acoustical Oceanography : Principles and Applications (John Wiley & Sons, New York, 1997), pp. 258-261.
  28. R. D. Stoll and T. K. Kan, "Reflection of acoustic waves at a water-sediment interface," J. Acoust. Soc. Am. 70, 149-156 (1981). https://doi.org/10.1121/1.386692
  29. P. D. Mourad and D. R. Jackson, "High frequency sonar equation models for bottom backscatter and forward loss," Proc. OCEAN'89, New York, 1168-1175 (1989).
  30. S. S. Park, K. S. Yoon, J. W. Choi, and J. Y. Na, " Frequency dependence of high-frequency bottom reflection loss measurements" (in Korean), J. Acoust. Soc. Kr. 22, 652-659 (2003).
  31. N. G. Pace, F. B. Jensen, Impact of Littoral Environmental Variability on Acoustic Predictions and Sonar Performance (Kluwer Academic Publishers, Dordrecht, 2002), pp. 195-202.
  32. M. J. Isakson, N. P. Chotiros, R. A. Yarbrough, and J. N. Piper, "Bottom loss modeling for sonar performance prediction," in Proc. Underwater Technology (UT), 2011 IEEE Symposium on and 2011 Workshop on Scientific Use of Submarine Cables and Related Technologies (SSC), 44-47 (2011).