scholarly journals Distributed Fiber-Optic Sensor for Detection and Localization of Acoustic Vibrations

2015 ◽  
Vol 22 (1) ◽  
pp. 111-118 ◽  
Author(s):  
Radim Sifta ◽  
Petr Munster ◽  
Petr Sysel ◽  
Tomas Horvath ◽  
Vit Novotny ◽  
...  
Keyword(s):  
Time Domain Reflectometry ◽  
Fiber Optic Sensor ◽  
Mechanical Vibrations ◽  
Distributed Sensor ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Distributed Fiber Optic Sensor ◽  
Phase Sensitive ◽  
Optical Time ◽  
Detection And Localization

Abstract A sensing system utilizing a standard optical fiber as a distributed sensor for the detection and localization of mechanical vibrations is presented. Vibrations can be caused by various external factors, like moving people, cars, trains, and other objects producing mechanical vibrations that are sensed by a fiber. In our laboratory we have designed a sensing system based on the Φ-OTDR (phase sensitive Optical Time Domain Reflectometry) using an extremely narrow laser and EDFAs.

scholarly journals Recent Advances in Distributed Acoustic Sensing Based on Phase-Sensitive Optical Time Domain Reflectometry

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Yonas Muanenda
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Fiber Optic Sensor ◽  
Acoustic Sensing ◽  
Rayleigh Backscattering ◽  
Recent Advances ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Distributed Acoustic Sensing ◽  
Optical Time

Distributed acoustic sensing (DAS) using coherent Rayleigh backscattering in an optical fiber has become a ubiquitous technique for monitoring multiple dynamic events in real time. It has continued to constitute a steadily increasing share of the fiber-optic sensor market, thanks to its interesting applications in many safety, security, and integrity monitoring systems. In this contribution, an overview of the recent advances of research in DAS based on phase-sensitive optical time domain reflectometry (ϕ-OTDR) is provided. Some advanced techniques used to enhance the performance of ϕ-OTDR sensors for measuring backscattering intensity changes through reduction of measurement noise are presented, in addition to methods used to increase the dynamic measurement capacity of ϕ-OTDR schemes beyond conventional limits set by the sensing distance. Recent ϕ-OTDR configurations which significantly enhance the measurement spatial resolution, including those which decouple it from the probing pulse width, are also discussed. Finally, a review of recent advances in more precise quantitative measurement of an external impact based on frequency shift and phase demodulation methods using simple direct detection ϕ-OTDR schemes is given.

scholarly journals Performance Optimization for Phase-Sensitive OTDR Sensing System Based on Multi-Spatial Resolution Analysis

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 83 ◽  
Author(s):  
Yuanyuan Shan ◽  
Wenbin Ji ◽  
Qing Wang ◽  
Lu Cao ◽  
Feng Wang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Performance Optimization ◽  
Signal To Noise Ratio ◽  
Time Domain Reflectometry ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Resolution Analysis ◽  
Phase Sensitive ◽  
Optical Time ◽  
Qualitative Relationship

This paper proposes and demonstrates a phase-sensitive optical time domain reflectometry (Φ-OTDR) sensing system with multi-spatial resolution (MSR) analysis property. With both theoretical analysis and an experiment, the qualitative relationship between spatial resolution (SR), signal-to-noise ratio (SNR) and the length of the vibration region has been revealed, which indicates that choosing a suitable SR to analyze the vibration event can effectively enhance the SNR of a sensing system. The proposed MSR sensing scheme offers a promising solution for the performance optimization of Φ-OTDR sensing systems, which can restore vibration events of different disturbance range with optimum SNR in merely a single measurement while maintaining the same detectable frequency range.

scholarly journals Fiber Optic Based Distributed Mechanical Vibration Sensing

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4779
Author(s):  
Vít Novotný ◽  
Petr Sysel ◽  
Aleš Prokeš ◽  
Pavel Hanák ◽  
Karel Slavíček ◽  
...  
Keyword(s):  
Mechanical Vibration ◽  
Single Mode ◽  
Time Domain Reflectometry ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Measurement Results ◽  
Vibration Sensing ◽  
Phase Sensitive ◽  
Optical Time ◽  
Initial Measurement

The distributed long-range sensing system, using the standard telecommunication single-mode optical fiber for the distributed sensing of mechanical vibrations, is described. Various events generating vibrations, such as a walking or running person, moving car, train, and many other vibration sources, can be detected, localized, and classified. The sensor is based on phase-sensitive optical time-domain reflectometry (ϕ-OTDR). Related sensing system components were designed and constructed, and the system was tested both in the laboratory and in the real deployment, with an 88 km telecom optical link, and the results are presented in this paper. A two-fiber sensor unit, with a double-sensing range was also designed, and its scheme is described. The unit was constructed and the initial measurement results are presented.

scholarly journals Recent Advances in Phase-Sensitive Optical Time Domain Reflectometry (Ф-OTDR)

2021 ◽  
Vol 11 (1) ◽  
pp. 1-30
Author(s):  
Yunjiang Rao ◽  
Zinan Wang ◽  
Huijuan Wu ◽  
Zengling Ran ◽  
Bing Han
Keyword(s):  
Fiber Optics ◽  
Time Domain ◽  
Acoustic Waves ◽  
Rapid Development ◽  
Development Stage ◽  
Time Domain Reflectometry ◽  
Rayleigh Backscattering ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Optical Time

AbstractPhase-sensitive optical time domain reflectometry (Ф-OTDR) is an effective way to detect vibrations and acoustic waves with high sensitivity, by interrogating coherent Rayleigh backscattering light in sensing fiber. In particular, fiber-optic distributed acoustic sensing (DAS) based on the Ф-OTDR with phase demodulation has been extensively studied and widely used in intrusion detection, borehole seismic acquisition, structure health monitoring, etc., in recent years, with superior advantages such as long sensing range, fast response speed, wide sensing bandwidth, low operation cost and long service lifetime. Significant advances in research and development (R&D) of Ф-OTDR have been made since 2014. In this review, we present a historical review of Ф-OTDR and then summarize the recent progress of Ф-OTDR in the Fiber Optics Research Center (FORC) at University of Electronic Science and Technology of China (UESTC), which is the first group to carry out R&D of Ф-OTDR and invent ultra-sensitive DAS (uDAS) seismometer in China which is elected as one of the ten most significant technology advances of PetroChina in 2019. It can be seen that the Ф-OTDR/DAS technology is currently under its rapid development stage and would reach its climax in the next 5 years.

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