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Multi-Frequency Φ-OTDR DAS Using Timely-Updated Vector-Based Phase Averaging
DOI:10.1109/JLT.2024.3460829.png)
摘要
En 中文
Distributed acoustic sensing (DAS) using optical fiber cables, widely deployed for communications, can capture various information on the surrounding environment. Phase-sensitive optical time-domain reflectometry (Phi-OTDR) DAS is suitable for sensing deployed cables because Phi-OTDR has long measurement distances. However, a simple Phi-OTDR setup suffers from interference fading, in which sensitivity degradation occurs at many points. Multi-frequency Phi-OTDR is a practical solution that can remove the sensitivity degradation points effectively by averaging the signals of multi-frequency pulses. The method used to average multi-frequency signals affects the total measurement performance, including the sensitivity and the measurable vibration amplitude range. While vector-based averaging on the IQ plane is a powerful method in terms of sensitivity, calculating accurate vibration waveforms becomes difficult when vibrations become strong (> sub-mu epsilon). Consequently, large-scale vibration patterns are not accurately visualized, limiting potential applications. In this work, we develop a vector-based averaging method that can resolve this issue. We clarify that the known problem of the difference in phase response to strain change between multiplexed frequencies is the key matter causing the issue. To address this discrepancy, we propose a dynamically updated vector-based averaging method, enabling us to monitor strong vibrations. In the proposed method, parameters used in vector-based averaging-rotation angles and reference frequencies-that are fixed in the conventional method are updated over time in accordance with the fiber state. We demonstrate the effectiveness of the proposed method in both laboratory and field environments. We successfully visualize patterns of large-scale vibrations experienced by field-deployed communication cables, such as those caused by vehicle movements and wind blowing.
Keyword:
Vibrations
Vectors
Sensitivity
Optical fibers
Vibration measurement
Optical fiber networks
Optical fiber sensors
Communication fiber network
distributed acoustic sensing
distributed fiber-optic sensing
phase-sensitive optical time-domain reflectometry
期刊
IF:
4.8
论文数:
1.7W
被引数:
3.8W
机构
暂无机构信息
引用论文
Deployment Condition Visualization of Aerial Optical Fiber Cable By Distributed Vibration Sensing Based On Optical Frequency Domain Reflectometry基于光频域反射的分布式振动传感空中光缆部署状态可视化
Phase-detection distributed fiber-optic vibration sensor without fading-noise based on time-gated digital OFDR
OPTICS EXPRESS
IF3.3
Performance analysis of distributed optical fiber acoustic sensors based on φ-OTDR
OPTICS EXPRESS
IF3.3
Dynamic strain determination using fibre-optic cables allows imaging of seismological and structural features
NATURE COMMUNICATIONS
IF15.7

