• Title/Summary/Keyword: ircle of appollonios

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Underwater Target Localization Using the Interference Pattern of Broadband Spectrogram Estimated by Three Sensors (3개 센서의 광대역 신호 스펙트로그램에 나타나는 간섭패턴을 이용한 수중 표적의 위치 추정)

  • Kim, Se-Young;Chun, Seung-Yong;Kim, Ki-Man
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.4
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    • pp.173-181
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    • 2007
  • In this paper, we propose a moving target localization algorithm using acoustic spectrograms. A time-versus-frequency spectrogram provide a information of trajectory of the moving target in underwater. For a source at sufficiently long range from a receiver, broadband striation patterns seen in spectrogram represents the mutual interference between modes which reflected by surface and bottom. The slope of the maximum intensity striation is influenced by waveguide invariant parameter ${\beta}$ and distance between target and sensor. When more than two sensors are applied to measure the moving ship-radited noise, the slope and frequency of the maximum intensity striation are depend on distance between target and receiver. We assumed two sensors to fixed point then form a circle of apollonios which set of all points whose distances from two fixed points are in a constant ratio. In case of three sensors are applied, two circle form an intersection point so coordinates of this point can be estimated as a position of target. To evaluates a performance of the proposed localization algorithm, simulation is performed using acoustic propagation program.