The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
권호 표지

Measurements of High-frequency Sea Surface Backscattering Signals

고주파 해수면 후방산란 신호 측정

  • 최지웅 (한양대학교 지구해양과학과 해양음향연구실) ;
  • 나정열 (한양대학교 지구해양과학과 해양음향연구실) ;
  • 박경주 (한양대학교 지구해양과학과 해양음향연구실) ;
  • 윤관섭 (한양대학교 지구해양과학과 해양음향연구실) ;
  • 박정수 (국방과학연구소) ;
  • 나영남 (국방과학연구소)
  • Published : 2002.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

Sea surface backscattering signal measurements were conducted in the shallow waters off the east coast of Korea to study the acoustic wave scattering from the sea surface. The grazing angles of wave range from 20° to 40° with a frequency of 60 kHz. The wind speed and surface roughness of the experiment area were 3 m/os and below 1 m, respectively. The measured acoustic backscattering strengths greatly exceed the composite roughness predictions at low grazing angles. To account for this discrepancy, the scattering strengths due to a near-surface bubble layer were considered. The prediction with bubble contribution was found to be in good agreement with the experimental measurement.

해수면에서의 음파산란 특성을 파악하기 위한 해수면 후방산란실험을 2000년 11월 동해시 연안에서 수행하였다. 평면입사각의 범위는 20°∼40°였고 주파수는 60 kHz였다. 실험해역의 풍속은 3 m/s, 해수면 거칠기는 1 m이하로 관측되었다. 분석된 해수면 후방산란강도는 경계면 산란강도 예측 모델에 비해서 높게 나타났으며 이러한 차이는 작은 평면입사각에서 더욱 크게 나타났다. 이러한 차이를 설명하기 위하여 해수면 부근의 공기방울층에 의한 산란 효과를 고려한 결과 실측치와 모델이 잘 일치하였다.

Keywords

References

  1. 한국음향학회지 v.19 no.2 내만에서의 해수면 후방산란신호 특성 최지웅;나정열;조운현
  2. 한국음향학회지 v.20 no.4 양상태 해수면 음파산란 측정 최지웅;나정열;나영남
  3. J. Geophys. Res. v.87 no.C6 Acoustic and radar sea surface backscatter S. T. McDaniel;A. D. Gorman https://doi.org/10.1029/JC087iC06p04127
  4. J. Acoust. Soc. Am. v.94 no.4 Sea surface reverberation: A review S. T. McDaniel https://doi.org/10.1121/1.407514
  5. J. Acoust. Soc. Am. v.100 On the spatial coherence and angular spreading of sound forward scattered from the sea surface; Measurements and interpretive model P. H. Dahl https://doi.org/10.1121/1.416237
  6. J. Acoust. Soc. Am. v.101 no.5 Simultaneous acoustic and microwave backscattering from the sea surface P. H. Dahl;W. J. Plant;B. Nutzel;A. Schmidt;E. A. Terray https://doi.org/10.1121/1.418500
  7. J. Acoust. Soc. Am. v.105 no.4 On bistatic sea surface scattering; Field measurements and modeling P. H. Dahl https://doi.org/10.1121/1.426820
  8. J. Acoust. Soc. Am. v.34 Surface backscattering strengths measured with explosive charges R. P. Chapman;J. H. Harris https://doi.org/10.1121/1.1909057
  9. J. Acoust. Soc. Am. v.36 Surface backscattering strengths measured over an extended range of frequencies and grazing angles R. P. Chapman;H. D. Scott https://doi.org/10.1121/1.1919274
  10. Sov. Phys. Acoust. v.8 The scattering of sound waves at a rough surface with two types of irregularity B. F. Kur'ynov
  11. Cavitation and Inhomogeneities in Underwater Acoustics Acoustic scattering from near-surface bubble layers P. A. Crowther;W. Lauterborn(ed.)
  12. J. Acoust. Soc. Am. v.89 Echoes from vertically striated subresonant bubble clouds;a model for ocean surface reverberation B. E. McDonald https://doi.org/10.1121/1.400386
  13. J. Acoust. Soc. Am. v.90 Acoustic scattering from ocean microbubble plumes in the 100Hz to 2kHz region F. S. Henyey https://doi.org/10.1121/1.401264
  14. Fundamentals of Ocean Acoustics(2nd ed) L. M. Brekhovskikh;Yu. P. Lysanov
  15. Philos. Trans. R. Soc. London Ser. A v.315 Directional spectra of wind generated waves M. A. Donelan;J. Hamilton;W. H. Hui https://doi.org/10.1098/rsta.1985.0054
  16. NASA Contract Rep. CR-2646 The theory and applications of ocean wave measuring systems at and below the sea surface, on the land, and from aircraft and spacecraft W. J. Pierson
  17. J. Fluids Eng. v.110 Comparison of holographic and Coulter Counter measurements of cavitation nuclei in the ocean T. J. O'Hern(et al.) https://doi.org/10.1115/1.3243535
  18. J. Acoust. Soc. Am. v.31 Survey of thermal, radiation, and viscous damping of pulsating air bubbles in water Jr. C. Devin
  19. Fundamentals of Acoustical Oceanography H. Medwin;C. S. Clay
  20. J. Geophys. Res. v.86 Bubble populations and spectra in near-surface ocean;Summary and review of field measurements J. Wu https://doi.org/10.1029/JC086iC01p00457
  21. J. Acoust. Soc. Am. v.74 Spectral spread of sea-surface reverberation S. T. McDaniel;A. D. Gorman https://doi.org/10.1121/1.389716
  22. J. Geophys. Res. v.84 Bubble populations and spectra in coastal waters;a photographic approach B. D. Johnson;R. C. Cooke https://doi.org/10.1029/JC084iC07p03761
  23. Principles of Underwater Sound R. J. Urick
  24. J. Acoust. Soc. Am. v.72 no.3 Sound absorption based on ocean measurements: PartⅠ: Pure water and magnesium sulfate contributions R. E. Francois;G. R. Garrison https://doi.org/10.1121/1.388170
  25. J. Acoust. Soc. Am. v.72 no.6 Sound absorption based on ocean measurements: Part Ⅱ: Boric acid contribution and equation for total absorption R. E. Francois;G. R. Garrison https://doi.org/10.1121/1.388673
  26. Naval Underwater Syst. Ctr., Tech. Doc. v.5971A Generic Sonar Model H. Weinberg
  27. Proc. OCEAN'89 High frequency sonar equation models for bottom backscatter and forward loss P. D. Mourad;D. R. Jackson
  28. APL-UW High-Frequency Ocean Environmental Acoustic Models Handbook
  29. Underwater Acoustic System Analysis W. S. Burdic