Estimation of surficial sediment thickness using mid-frequency ocean acoustic bottom reflected signals measured in shallow water off Geoje island

Hyuckjong  Kwon; Jee Woong  Choi; Su-Uk  Lee; Sungho Cho; Jooyoung Hahn; Joung-Soo  Park; Kyeongju  Park

doi:10.7776/ASK.2016.35.6.419

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Estimation of surficial sediment thickness using mid-frequency ocean acoustic bottom reflected signals measured in shallow water off Geoje island 거제 인근해역에서 측정된 중주파수 음향 해저면 반사 신호를 이용한 표층 해저면 두께 추정

30 November 2016. pp. 419-426

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Abstract

Measurements of bottom loss as a function of grazing angle (in range of 9~14°) at a frequency range of 4~8 kHz were conducted on an experimental site off Geoje island in October 2015. Geoacoustic inversion of the surficial sediment thickness is performed using the arrival time difference between the surficial layer and the sub-bottom layer reflected signal. To invert the thickness of surficial sediment, we used the grain size of 8~10 ϕ obtained by KIGAM (Korea Institute of Geoscience and Mineral Resources). The thickness of the surficial sediment was estimated to be 4~7 m. Finally, this inversion result was compared with the geoacoustic observation conducted by the KIOST (Korea Institute of Ocean Science & Technology) using sub-bottom profiler.

Keywords

Geoacoustic inversion

Bottom reflection

Arrival time difference

천해 환경에서 수평입사각에 따른 음향반사 신호 측정 실험을 2015년 10월 거제 인근 해역에서 실시하였다. 본 논문에서는 수평입사각 9~14° 범위에서 측정된 중주파수 4 ~ 8 kHz의 표층 해저면 반사 신호와 하부 퇴적층 반사 신호의 도달시간 차이를 이용하여 표층 퇴적층의 두께를 역으로 추정하였다. 실험 해역의 지질 정보는 한국지질자원연구원에서 제공한 실험 해역의 평균입도범위인 8 ~ 10 ϕ를 사용하였다. 두 다중경로의 도달시간 차이를 이용하여 추정한 표층 퇴적층의 두께는 4 ~ 7 m이며, 한국해양과학기술원이 제공한 실험 해역 인근의 천부지층탐사기를 이용한 하부 퇴적층 분석 결과와 비교하였다.

키워드

지음향 역산

해저면 반사

도달시간 차이

References

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Information

Publisher :The Acoustical Society of Korea
Publisher(Ko) :한국음향학회
Journal Title :The Journal of the Acoustical Society of Korea
Journal Title(Ko) :한국음향학회지
Volume : 35
No :6
Pages :419-426
Received Date : 2016-09-20
Revised Date : 2016-10-14
Accepted Date : 2016-11-25
DOI :https://doi.org/10.7776/ASK.2016.35.6.419

The Journal of the Acoustical Society of KoreaISSN:1225-4428(Print) 2287-3775(Online)한국음향학회

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