Shen Zhichao, Wu Wenbo, Lin Ying-Tsong
Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA.
J Acoust Soc Am. 2024 Oct 1;156(4):2237-2249. doi: 10.1121/10.0030400.
Distributed acoustic sensing (DAS), converting fiber-optic cables into dense acoustic sensors, is a promising technology that offers a cost-effective and scalable solution for long-term, high-resolution studies in ocean acoustics. In this paper, the telecommunication cable of Martha's Vineyard Coastal Observatory (MVCO) is used to explore the feasibility of cable localization and shallow-water sound propagation with a mobile acoustic source. The MVCO DAS array records coherent, high-quality acoustic signals in the frequency band of 105-160 Hz, and a two-step inversion method is used to improve the location accuracy of DAS channels, reducing the location uncertainty to ∼2 m. The DAS array with refined channel positions enables the high-resolution observation of acoustic modal interference. Numerical simulations that reproduce the observed interference pattern suggest a compressional speed of 1750 m/s in the sediment, which is consistent with previous in situ geoacoustic measurements. These findings demonstrate the long-term potential of DAS for high-resolution ocean acoustic studies.
分布式声学传感（DAS）技术可将光纤电缆转变为密集的声学传感器，是一项很有前景的技术，为海洋声学的长期、高分辨率研究提供了经济高效且可扩展的解决方案。在本文中，玛莎葡萄园岛海岸观测站（MVCO）的通信电缆被用于探索利用移动声源进行电缆定位和浅海声传播的可行性。MVCO DAS阵列在105 - 160赫兹频段记录了相干、高质量的声学信号，并采用两步反演方法提高DAS通道的定位精度，将定位不确定性降低至约2米。具有精确通道位置的DAS阵列能够对声学模态干涉进行高分辨率观测。再现观测到的干涉图样的数值模拟表明，沉积物中的压缩波速度为1750米/秒，这与之前的现场地球声学测量结果一致。这些发现证明了DAS在高分辨率海洋声学研究中的长期潜力。
