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Robust variable range focusing with a virtual source array using the waveguide invariant in underwater

수중에서의 도파관 불변성을 이용한 가상 음원 배열 기반의 다양한 거리 방향으로의 강인한 집속

Gi Hoon Byun1
,
J. S. Kim2*
변 기훈1
,
김 재수2*
2Department of Engineering, Korea Maritime and Ocean University
1한국해양과학기술원-한국해양대학교 해양과학기술전문대학원
2한국해양대학교 해양공학과
*교신저자. *Corresponding Author. 
31 January 2017. pp. 23-29
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Abstract

A concept of a VSA (Virtual Source Array) is the method for an acoustic spatio-temporal focus at a selected location in the outbound direction with respect to the VSA without the need of a probe source as combines a TRP (Time-Reversal Processing) and time-delay and beam-steering. However, in TRP using the VSA concept, it is limited to the critical angle and the short distances relevant to the VSA. In this paper, the waveguide invariant theory is applied to the VSA concept to refocus the received field at ranges greater other than the critical angle and the short ranges by shifting the focused field. The suggested method is verified via numerical simulation, and the results show that the robust acoustic focusing is achieved on the selected location regardless of the limitation on the conventional VSA concept.

Keywords
Time-reversal processing
Virtual source array
Waveguide invariant
Time-delay and beam-steering

가상 음원 배열 개념은 시역전 처리에 시지연 빔조향 기법을 적용함으로써 가상 음원 배열로부터 나아가는 방향에 해당하는 선택된 위치에 음원 없이도 음파의 시·공간적 집속을 수행하는 방법이다. 하지만 가상 음원 배열 개념을 이용한 시역전 처리 방법은 가상 음원 배열에 해당하는 임계각 및 근거리를 벗어나는 범위로의 음파 집속이 불가능하다는 제약 조건이 따른다. 본 논문에서는 이러한 제약 조건을 해결하기 위해, 도파관 불변성 이론을 가상 음원 배열 개념에 적용하여 집속 음장의 수평 방향으로의 이동을 통해 임계각 및 근거리를 벗어나는 구간으로의 음파 집속 방법에 대한 연구를 수행하였다. 수치 실험의 결과를 통해 본 연구의 타당성을 검증하였으며, 기존의 가상 음원 배열 개념의 제약 조건에 관계없이 선택된 위치에서의 강인한 음파 집속 성능의 결과를 보였다.

키워드
시역전 처리
가상 음원 배열
도파관 불변성
시지연 빔조향
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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 : 36
  • No :1
  • Pages :23-29
  • Received Date : 2016-11-30
  • Accepted Date : 2017-01-25
  • DOI :https://doi.org/10.7776/ASK.2017.36.1.023
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