单边噪声源环境下的格林函数提取

发布时间：2018-04-14 20:52

本文选题：噪声源 + 格林函数　；参考：《声学学报》2017年02期

【摘要】：对单边噪声源环境下空间中存在散射体时的格林函数到达时间结构提取展开了实验性研究。通过对位于沙滩上的传声器上记录的海浪噪声进行互相关处理,成功提取出两传声器间的格林函数到达时间结构。到达时间结构中观察到伪散射路径,并且伪散射路径在幅值上远高于散射路径。针对上述现象给出了理论及仿真解释:当传声器对受噪声源单边照射时,广义光学定理失效,伪散射路径将会出现;同时,由于伪散射路径由所有方向噪声源贡献,散射路径仅有稳相点附近声源贡献,因此伪散射路径在幅值上可能高于散射路径。结果表明,在单边噪声源环境下,基于互相关技术可以提取伪散射路径。伪散射路径的短时稳定提取可以为散射体无源成像提供更多信息,在海洋声学、地震学等领域具有潜在应用价值。
[Abstract]:An experimental study on the extraction of the time structure of arrival of Green's function in the presence of scatterers in the environment of unilateral noise sources is carried out.The time of arrival structure of Green's function between two microphones was extracted by cross-correlation of wave noise recorded on a microphone on the beach.The pseudo-scattering path is observed in the time of arrival structure, and the pseudo-scattering path is much higher than the scattering path in amplitude.In view of the above phenomena, the theoretical and simulation explanations are given: when the microphone is irradiated unilaterally by the noise source, the generalized optical theorem will fail and the pseudo-scattering path will appear. At the same time, the pseudo-scattering path will be contributed by all direction noise sources.The scattering path contributes only to the sound source near the stationary phase point, so the pseudo-scattering path may be higher in amplitude than the scattering path.The results show that pseudo-scattering paths can be extracted based on cross-correlation in single side noise source environment.Short-term stable extraction of pseudo-scattering paths can provide more information for passive imaging of scatterers and has potential applications in ocean acoustics seismology and other fields.
【作者单位】：中国海洋大学海洋技术系;国家海洋技术中心;青岛市海洋科技协同创新中心;
【基金】：国家自然科学基金项目(11374270,11374271)资助
【分类号】：TN641

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