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 Sub-Meter Spatial Resolution Phase-Sensitive Optical Time-Domain Reflectometry System Using Double Interferometers

2018 ◽  
Vol 8 (10) ◽  
pp. 1899 ◽  
Author(s):  
Shengwen Feng ◽  
Tuanwei Xu ◽  
Jianfen Huang ◽  
Yang Yang ◽  
Lilong Ma ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Bilateral Filtering ◽  
Rayleigh Backscattering ◽  
Detection Frequency ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Optical Time ◽  
Phase Generated Carrier

An improved phase-sensitive optical time-domain reflectometry (φ-OTDR) system with sub-meter spatial resolution is demonstrated. Two Michelson interferometers (MIs) with different path length differences are used in the proposed system. One is 10 m, the other is 9.2 m. Two Rayleigh backscattering phase traces with different spatial resolution are obtained by a phase generated carrier (PGC) algorithm at adjacent times. After using differencing and adaptive 2-D bilateral filtering algorithms, a 0.8-m spatial resolution over 2 km is achieved. Experimental results indicate that the system shows an extraordinary linearity as high as 99.94% with amplitude-modulation and acquires a detection frequency from 5 to 500 Hz.

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 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 Time-expanded phase-sensitive optical time-domain reflectometry

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Miguel Soriano-Amat ◽  
Hugo F. Martins ◽  
Vicente Durán ◽  
Luis Costa ◽  
Sonia Martin-Lopez ◽  
...  
Keyword(s):  
Time Domain ◽  
Signal To Noise Ratio ◽  
Random Phase ◽  
Environmental Variable ◽  
Time Domain Reflectometry ◽  
Trade Offs ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Spatio Temporal ◽  
Optical Time

AbstractPhase-sensitive optical time-domain reflectometry (ΦOTDR) is a well-established technique that provides spatio-temporal measurements of an environmental variable in real time. This unique capability is being leveraged in an ever-increasing number of applications, from energy transportation or civil security to seismology. To date, a wide number of different approaches have been implemented, providing a plethora of options in terms of performance (resolution, acquisition bandwidth, sensitivity or range). However, to achieve high spatial resolutions, detection bandwidths in the GHz range are typically required, substantially increasing the system cost and complexity. Here, we present a novel ΦOTDR approach that allows a customized time expansion of the received optical traces. Hence, the presented technique reaches cm-scale spatial resolutions over 1 km while requiring a remarkably low detection bandwidth in the MHz regime. This approach relies on the use of dual-comb spectrometry to interrogate the fibre and sample the backscattered light. Random phase-spectral coding is applied to the employed combs to maximize the signal-to-noise ratio of the sensing scheme. A comparison of the proposed method with alternative approaches aimed at similar operation features is provided, along with a thorough analysis of the new trade-offs. Our results demonstrate a radically novel high-resolution ΦOTDR scheme, which could promote new applications in metrology, borehole monitoring or aerospace.

scholarly journals Влияние дрейфа частоты лазера в фазочувствительной рефлектометрии

2019 ◽  
Vol 127 (10) ◽  
pp. 603
Author(s):  
А.А. Жирнов ◽  
К.В. Степанов ◽  
А.О. Чернуцкий ◽  
А.К. Федоров ◽  
Е.Т. Нестеров ◽  
...  
Keyword(s):  
Time Domain ◽  
Signal To Noise Ratio ◽  
Frequency Instability ◽  
Laser Frequency ◽  
Time Domain Reflectometry ◽  
Laser Source ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Optical Time ◽  
Theoretical Results

AbstractThe influence of the laser frequency drift on the operation of phase-sensitive optical time domain reflectometry (φ-OTDR) systems is considered. Theoretical results based on a new numerical φ-OTDR model demonstrating the influence of the laser frequency instability on a signal are reported. This model is verified based on experimental data. It has been used to calculate the signal-to-noise ratio (SNR) of the system for different parameters of the laser source stability. As a result, quantitative requirements for lasers used in φ-OTDR systems are formulated.

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