Evaluating seismic beamforming capabilities of distributed acoustic sensing arrays
Evaluating seismic beamforming capabilities of distributed acoustic sensing arrays
复制标题
评估分布式声学传感阵列的地震波束形成能力
DOI：
10.5194/se-12-915-2021
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
J. Ampuero
中科院分区：
文献类型：
--
作者：
M. van den Ende;J. Ampuero
抽象。光纤分布式声学传感（DAS）技术的多功能性和成本效益有助于在以前仪器无法访问的环境中进行地球物理监测。此外，DAS所允许的时空数据密度自然地呼吁地震阵列处理技术，例如用于源定位的波束形成。然而，DAS的测量原理与传统地震仪的测量原理有本质的不同，它提供的是地面应变而不是地面运动的测量，因此传统地震学方法的适用性需要深入评估。在这项研究中，我们评估的DAS阵列的地震波束形成的任务中的性能，在一个共同定位的节点地震计阵列相比。我们发现，即使节点阵列在定位区域ML 4.3地震方面取得了优异的性能，DAS阵列表现出较差的波形相干性，从而产生不充分的波束形成结果，主要是由浅散射波的签名。我们证明，这种行为可能是固有的DAS测量原理，因此需要采取新的策略来调整阵列处理技术，这种新兴的测量技术。这里展示的一种策略是使用节点地震计记录作为参考，通过空间积分将DAS应变率转换为粒子速度，这大大提高了波形相干性和波束形成性能，并保证了将密集DAS阵列与稀疏地震计阵列相结合的新型“混合”阵列设计。
Abstract. The versatility and cost efficiency of fibre-optic distributed acoustic sensing (DAS) technologies facilitate geophysical monitoring in environments that were previously inaccessible for instrumentation. Moreover, the spatio-temporal data density permitted by DAS naturally appeals to seismic array processing techniques, such as beamforming for source location. However, the measurement principle of DAS is inherently different from that of conventional seismometers, providing measurements of ground strain rather than ground motion, and so the suitability of traditional seismological methods requires in-depth evaluation. In this study, we evaluate the performance of a DAS array in the task of seismic beamforming, in comparison with a co-located nodal seismometer array. We find that, even though the nodal array achieves excellent performance in localising a regional ML 4.3 earthquake, the DAS array exhibits poor waveform coherence and consequently produces inadequate beamforming results that are dominated by the signatures of shallow scattered waves. We demonstrate that this behaviour is likely inherent to the DAS measurement principle, and so new strategies need to be adopted to tailor array processing techniques to this emerging measurement technology. One strategy demonstrated here is to convert the DAS strain rates to particle velocities by spatial integration using the nodal seismometer recordings as a reference, which dramatically improves waveform coherence and beamforming performance and warrants new types of “hybrid” array design that combine dense DAS arrays with sparse seismometer arrays.
影响因子：
2.8
作者：
D. Zigone;Y. Ben‐Zion;M. Lehujeur;M. Campillo;G. Hillers;F. Vernon
通讯作者：
D. Zigone;Y. Ben‐Zion;M. Lehujeur;M. Campillo;G. Hillers;F. Vernon
从瑞利和 S 波断层扫描看阿拉斯加的上地幔地震结构
影响因子：
5.2
作者：
Jiang, Chengxin;Schmandt, Brandon;Ward, Kevin M.;Lin, Fan‐Chi;Worthington, Lindsay L.
通讯作者：
Worthington, Lindsay L.