The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Mid-high frequency ocean surface-generated ambient noise model and its applications

중고주파 해수면 생성 배경소음 모델과 응용

  • Lee, Keunhwa ;
  • Seong, Woojae (Department of Naval Architecture and Ocean Engineering/RIMSE (Research Institute of Marine Systems Engineering), Seoul National University)
  • 이근화 (세종대학교 국방시스템공학과) ;
  • 성우제 (서울대학교 조선해양공학과/해양시스템공학연구소)
  • Received : 2016.06.07
  • Accepted : 2016.08.01
  • Published : 2016.09.30
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Abstract

Ray-based model for the calculation of the ocean surface-generated ambient noise coherence function has the form of double integral with respect to a range and a bearing angle. While the theoretical consideration about its numerical implementations was partly given in the past work of authors, the numerical results on the ocean environment have not been presented yet. In this paper, we perform numerical experiments for shallow and deep water environments. It is shown that the coherence function depends on the ocean sediment sound speed, and is more sensitive to the ocean sediment sound speed in the shallow water than in the deep water. Similar trend is also observed for varying the orientation of hydrophone pair. In addition, a post-processing technique is proposed in order to plot the noise intensity for the noise receiving angle. This procedure will supplement the weakness of the ray-based model about the output data type compared to the semi-analytic model of Harrison.

해수면 생성 배경소음에 대한 코히런스함수를 계산하기 위한 음선 기반 모델은 거리와 방위각에 대한 이중적분의 형태를 띤다. 이를 수치적으로 계산하기 위한 이론적인 고려사항은 본 저자들의 과거의 연구에서 부분적으로 설명되었으나, 해양 환경에서의 수치 해석은 수행된 적이 없다. 본 연구에서는 천해와 심해 환경에서 수치실험을 수행하였고, 이를 통해 코히런스함수는 해저 퇴적층음속에 의존하며, 심해보다는 천해에서 해저 퇴적층음속에 민감하다는 것을 보였다. 비슷한 경향이 수신기 쌍의 자세가 변하는 경우에도 관찰된다. 추가적으로 소음수신각에 대한 소음인텐서티를 표현하기 위한 후처리 기술이 제안되었다. 이 기술은 Harrison의 준해석적 모델과 비교할 때, 출력 자료의 형식에 대한 음선 기반 모델의 단점을 보완할 수 있을 것이다.

Keywords

References

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