Opt Lett. 2020 Oct 15;45(20):5672-5675. doi: 10.1364/OL.404736.
Distributed fiber acoustic sensing (DAS) can detect almost all disturbances along the sensing fiber and is widely applied. However, the signals from multiple adjacent disturbance sources are superimposed, according to the sensing principle. A directionally coherent enhancement technology is demonstrated for DAS to suppress multi-source aliasing in air. In preliminary works, two situations are considered for feasibility verification. The submerged weak target signal is effectively extracted from strong broadband noise, and two different same-frequency signals from two sources are separately rebuilt with the same detected signal. As far as we know, this is the first time that the directionally coherent enhancement is proposed for DAS and the multi-source aliasing is suppressed. This technique will help DAS find new important foreground in acoustic detection of large-scale plants with many similar noisy devices, including discharge detection in high voltage substations and acoustic emission flaw detection in mechanical factories.
分布式光纤声传感（DAS）可检测沿传感光纤的几乎所有干扰，应用广泛。然而，根据传感原理，多个相邻干扰源的信号会叠加。本文提出了一种针对 DAS 的方向相干增强技术，以抑制空气中的多源混叠。在初步工作中，考虑了两种情况来验证可行性。从强宽带噪声中有效地提取出淹没的弱目标信号，并利用相同的检测信号分别重建来自两个源的两个不同的同频信号。据我们所知，这是首次将方向相干增强技术应用于 DAS 并抑制多源混叠。该技术将有助于 DAS 在具有许多类似噪声设备的大型工厂的声学检测中找到新的重要应用前景，包括高压变电站中的放电检测和机械工厂中的声发射缺陷检测。
