한국음향학회지 (The Journal of the Acoustical Society of Korea)

  • 제38권4호
  • /
  • Pages.378-386
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  • 2019
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  • 1225-4428(pISSN)
  • /
  • 2287-3775(eISSN)
한국음향학회 (The Acoustical Society of Korea)
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동해 연안에서 관측된 풍속자료를 이용한 바람소음준위 추정 연구

A study on the estimation of wind noise level using the measured wind-speed data in the coastal area of the East Sea

  • 박지성 (한국해양과학기술원 해양방위.안전연구센터) ;
  • 강돈혁 (한국해양과학기술원 해양방위.안전연구센터) ;
  • 김미라 (한국해양과학기술원 해양방위.안전연구센터) ;
  • 조성호 (한국해양과학기술원 해양방위.안전연구센터)
  • 투고 : 2019.03.14
  • 심사 : 2019.04.18
  • 발행 : 2019.07.31
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초록

항해하는 선박으로부터 방사되는 선박소음과 달리 바람소음은 바람과 해수면의 상호작용으로 생성된 쇄파에 의해 발생한다. 본 논문에서는 바람의 소음원을 쇄파로 인해 발생되는 기포운으로 설정하여 바람소음준위를 모델링하였다. 모델링에서 바람소음의 음원준위는 동해 연안에서 운영되는 기상부이로부터 측정된 풍속 자료를 이용하여 계산하였다. 풍속을 측정함과 동시에 기상부이의 주변에 계류된 자가기록식 수중청음기를 이용하여 소음준위를 연속적으로 측정하였다. 측정된 수중소음에서 선박소음을 제거한 소음준위와 풍속에 따라 모델링된 바람소음준위를 저주파대역에서 비교하였다. 모델링된 바람소음준위와 측정된 소음준위의 전반적인 경향이 서로 유사하였다. 이에 따라 바람에 의해 발생된 소음원인 기포운의 음원준위 및 분포 수심을 고려하여 천해역에서 바람소음준위를 모델링하는 것이 가능함을 확인하였다.

Unlike ship noise that radiates from moving ships, wind noise is caused by breaking waves as a result of the interaction between the wind and the sea surface. In this paper, WNL (Wind Noise Level) was modeled by considering the noise source of the wind as the bubble cloud generated by the breaking waves. In the modeling, SL( Source Level) of the wind noise was calculated using the wind-speed data measured from the weather buoy operated in the coastal area of the East Sea. At the same time as observing the wind speed, NL (Noise Level) was continuously measured using a self-recording hydrophone deployed near the weather buoy. The modeled WNL according to the wind speed and the measured NL removing the shipping noise from the acoustic raw data were compared in the low-frequency band. The overall trends between the modeled WNL and the measured NL were similar to each other. Therefore, it was confirmed that it is possible to model the WNL in the shallow water considering the SL and distribution depth of bubble cloud caused by the wind.

키워드

GOHHBH_2019_v38n4_378_f0001.png 이미지

Fig. 1. (a) Topography of the study area using the ETOPO1,[14] and (b) schematic diagram for mooring the SM3M.

GOHHBH_2019_v38n4_378_f0002.png 이미지

Fig. 3. Power spectrogram of noise: (a) ship noise, (b) underwater noise when the ship is not around the hydrophone (the unit of color bar is dB re 1 μPa2/Hz).

GOHHBH_2019_v38n4_378_f0003.png 이미지

Fig. 4. Weather data measured using the weather buoy: (a) wind speed, and (b) wind direction. Here, black dot: wind speed > 2 m/s, red dot: wind speed ≤ 2 m/s.

GOHHBH_2019_v38n4_378_f0004.png 이미지

Fig. 5. Sound speed according to water depth provided by KODC (Korea Oceanographic Data Center).

GOHHBH_2019_v38n4_378_f0005.png 이미지

Fig. 6. Transmission loss for the region (water depth: 3 m) within 100 km from the location where the hydrophone is deployed (water depth: 70 m). Here, the unit of the color bar is dB.

GOHHBH_2019_v38n4_378_f0006.png 이미지

Fig. 7. Comparison between the modeled wind noise level (blue solid line) and the measured wind noise level (red dot) at: (a) 500 Hz, (b) 630 Hz, (c) 800 Hz, and (d) 1 kHz.

GOHHBH_2019_v38n4_378_f0007.png 이미지

Fig. 8. Standard deviation of the measured wind noise level according to the wind speed.

GOHHBH_2019_v38n4_378_f0008.png 이미지

Fig. 2. Underwater noise measured using the hydrophone: (a) power spectrogram (the unit of color bar is dB re 1 μPa2/Hz), and (b) power spectral density at 500 Hz.

참고문헌

  1. W. M. Carey and R. B. Evens, Ocean Ambient Noise (Springer, New York, 2011), Chap. 5.
  2. M. D. Anguelova and P. Huq, "Effects of salinity on bubble cloud characteristics," J. Mar. Sci. Eng. 6, 1-17 (2018). https://doi.org/10.3390/jmse6010001
  3. J. H. Steele, S. A. Thorpe, and K. K. Turekian, Encyclopedia of Ocean Sciences, 2Ed. (Academic Press, Massachusetts, 2009), pp. 352-357.
  4. M. D. Anguelova and P. Huq, "Characteristics of bubble clouds at various wind speeds," J. Geophysical Research 117, C03036 (2012).
  5. J. L. Hanson, "Winds, Waves, and Bubbles at the Air-sea Boundary," Johns Hopkins APL Technical Digest 14, 200-208 (1993).
  6. G. M. Wenz, "Acoustic Ambient Noise in the Ocean: Spectra and Sources," J. Acoust. Soc. Am. 34, 1936-1956 (1962). https://doi.org/10.1121/1.1909155
  7. A. S. Burgess and D. J. Kewley, "Wind-generated surface noise source levels in deep water east of Australia," J. Acoust. Soc. Am. 73, 201-210 (1983). https://doi.org/10.1121/1.388840
  8. W. A. Kuperman and M. C. Ferla, "A shallow water experiment to determine the source spectrum level of wind-generated noise," J. Acoust. Soc. Am. 77, 2067-2073 (1985). https://doi.org/10.1121/1.391781
  9. H. Schmidt and W. A. Kuperman, "Estimation of surface noise source level from low-frequency seismoacoustic ambient noise measurements," J. Acoust. Soc. Am. 84, 2153-2162 (1988). https://doi.org/10.1121/1.397061
  10. A. Prosperetti and N. Q. Lu, "Cavitation and bubble bursting as sources of oceanic ambient noise," J. Acoust. Soc. Am. 84, 1037-1041 (1988). https://doi.org/10.1121/1.396739
  11. D. J. Kewley, D. G. Browning, and W. M. Carey, "Low-frequency wind-generated ambient noise source levels," J. Acoust. Soc. Am. 88, 1894-1902 (1990). https://doi.org/10.1121/1.400212
  12. Ocean Acoustics Library, KRAKEN normal-mode acoustic propagation model, http://oalib.hlsresearch.com
  13. R. J. Urick, Principles of Underwater Sound, 3Ed. (McGraw-Hill, New York, 1983), Chap. 7.
  14. NOAA, ETOPO1 Global Relief Model, http://www.ngdc.noaa.gov/mgg/global
  15. M. F. McKenna, D. Ross, S. M. Wiggins, and J. A. Hildebrand, "Underwater radiated noise from modern commercial ships," J. Acoust. Soc. Am. 131, 92-103 (2012). https://doi.org/10.1121/1.3664100
  16. Y. L. Gall and J. Bonnel, "Separation of moving ship striation patterns using physics-based filtering," Proc. Mtgs. Acoust. 19, 070073 (2013).
  17. Korea Oceanographic Data Center, Sound speed profile, http://www.nifs.go.kr
  18. D. R. Jackson, "APL-UW high-frequency ocean environmental acoustic models handbook," APL-UW, Tech. Rep., 1994.
  19. A. Prosperetti, "Bubble-related ambient noise in the ocean," J. Acoust. Soc. Am. 84, 1042-1054 (1988). https://doi.org/10.1121/1.396740
  20. H. Medwin and M. M. Beaky, "Bubble sources of the Knudsen sea noise spectra," J. Acoust. Soc. Am. 86, 1124-1130 (1989). https://doi.org/10.1121/1.398104
  21. S. Cho and J. W. Choi, "Measurements of Breaking Wave Noise in the Sea-Cliff Zone," Jpn. J. Appl. Phys. 49, 07HG05 (2010).