scholarly journals Recent Advancements in Rayleigh Scattering-Based Distributed Fiber Sensors

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xiaoyi Bao ◽  
Yuan Wang
Keyword(s):  
Rayleigh Scattering ◽  
Time Domain Reflectometry ◽  
Distributed Sensing ◽  
Dynamic Strain ◽  
Sound Waves ◽  
Fiber Sensors ◽  
Sensing Systems ◽  
Sensing Technology ◽  
Optical Time ◽  
Distributed Fiber Sensors

Recently, Rayleigh scattering-based distributed fiber sensors have been widely used for measurement of static and dynamic phenomena such as temperature change, dynamic strain, and sound waves. In this review paper, several sensing systems including traditional Rayleigh optical time domain reflectometry (OTDR), Φ-OTDR, chirped pulse Φ-OTDR, and optical frequency domain reflectometry (OFDR) are introduced for their working principles and recent progress with different instrumentations for various applications. Beyond the sensing technology and instrumentation, we also discuss new types of fiber sensors, such as ultraweak fiber Bragg gratings and random fiber gratings for distributed sensing and their interrogators. Ultimately, the limitations of Rayleigh-based distributed sensing systems are discussed.

scholarly journals Distributed Static and Dynamic Strain Measurements in Polymer Optical Fibers by Rayleigh Scattering

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5049
Author(s):  
Agnese Coscetta ◽  
Ester Catalano ◽  
Enis Cerri ◽  
Ricardo Oliveira ◽  
Lucia Bilro ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Time Domain ◽  
Rayleigh Scattering ◽  
Cost Effective ◽  
Time Domain Reflectometry ◽  
Dynamic Strain ◽  
Strain Measurements ◽  
Graded Index ◽  
Optical Time ◽  
Polymer Optical Fibers

We demonstrate the use of a graded-index perfluorinated optical fiber (GI-POF) for distributed static and dynamic strain measurements based on Rayleigh scattering. The system is based on an amplitude-based phase-sensitive Optical Time-Domain Reflectometry (ϕ-OTDR) configuration, operated at the unconventional wavelength of 850 nm. Static strain measurements have been carried out at a spatial resolution of 4 m and for a strain up to 3.5% by exploiting the increase of the backscatter Rayleigh coefficient consequent to the application of a tensile strain, while vibration/acoustic measurements have been demonstrated for a sampling frequency up to 833 Hz by exploiting the vibration-induced changes in the backscatter Rayleigh intensity time-domain traces arising from coherent interference within the pulse. The reported tests demonstrate that polymer optical fibers can be used for cost-effective multiparameter sensing.

scholarly journals Interferometric distributed sensing system with phase optical time-domain reflectometry

2016 ◽  
Vol 7 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Chen Wang ◽  
Ying Shang ◽  
Xiaohui Liu ◽  
Chang Wang ◽  
Hongzhong Wang ◽  
...  
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Distributed Sensing ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Optical Time

Greatly Extended Distance Pipeline Monitoring Using Fibre Optics

2005 ◽  
Author(s):  
M. Nikles ◽  
F. Briffod ◽  
R. Burke ◽  
G. Lyons
Keyword(s):  
Time Domain Reflectometry ◽  
Distributed Sensing ◽  
Fibre Optics ◽  
Distributed Temperature Sensor ◽  
Optical Time Domain Reflectometry ◽  
Pipeline Monitoring ◽  
Optical Time ◽  
Fibre Bragg Gratings ◽  
Active Flow ◽  
Single Instrument

Monitoring of the effects of hydrocarbon pipeline blockages such as may be caused by hydrates and waxes is receiving a higher level of consideration as the distributed sensing capability offered by the use of fibre optic technology matures. The extent of the hydrate or wax formation problem increases with pipeline length through the effects of cooling. The challenge is significantly greater when assuring flows in deep water and remote subsea locations. Commercially available strain and temperature sensing equipment such as discrete FBGs (Fibre Bragg Gratings) and fully distributed sensing techniques such as Raman DTS (distributed temperature sensor) and Brillouin OTDR (optical time domain reflectometry) typically offer sensing lengths of the order of 20–30km. Whilst this is in many instances a useful length, it is not sufficient to be able to monitor the whole of a pipeline which may be several hundreds of kilometres in length. The authors have developed and demonstrated a method for extending the reach of a Brillouin OTDR interrogating system such that sensing sections of conventional length (approximately 25km) can be successfully interrogated from distances well in excess of 100km without having to compromise on the performance. With a single instrument, more than 250km of sensing fibre can be monitored to within 1.5 metre resolution. By this means, temperature and strain profiles may be measured for the entire pipeline length which will enable active flow assurance measures to be taken including identifying the presence, nature and extent of blockages as they form. Consequently, any corrective action taken by the pipeline operators will be on an informed basis (such as the injection of an optimised quantity of inhibitor), and will incur a significantly lower level of risk than is currently possible. This paper describes the technology which has been developed to meet this requirement and provides results of simulated pipeline blockage effects which demonstrate this.

scholarly journals Note: Gaussian mixture model for event recognition in optical time-domain reflectometry based sensing systems

2016 ◽  
Vol 87 (3) ◽  
pp. 036107 ◽  
Author(s):  
A. K. Fedorov ◽  
M. N. Anufriev ◽  
A. A. Zhirnov ◽  
K. V. Stepanov ◽  
E. T. Nesterov ◽  
...  
Keyword(s):  
Gaussian Mixture Model ◽  
Mixture Model ◽  
Time Domain ◽  
Gaussian Mixture ◽  
Time Domain Reflectometry ◽  
Event Recognition ◽  
Sensing Systems ◽  
Optical Time Domain Reflectometry ◽  
Optical Time

Fiber-Optic Sensing Technology for Rail-Buckling Detection

1997 ◽  
Vol 1584 (1) ◽  
pp. 41-45 ◽  
Author(s):  
James M. Signore ◽  
Mohamed G. Abdel-Maksoud ◽  
Barry J. Dempsey
Keyword(s):  
Fiber Optic ◽  
Field Testing ◽  
Time Domain Reflectometry ◽  
Robust Solution ◽  
Sensing System ◽  
Sensing Technology ◽  
Optical Time Domain Reflectometry ◽  
Theoretical Predictions ◽  
Fiber Optic Sensing ◽  
Optical Time

Buckling and cracking of steel rails is a contributing factor in accidents on railroads today. Detection and notification of buckled track sections before a train reaches these locations will significantly increase rail safety. A fiber-optic-based sensing system, with the fiber affixed to a beam, was developed and evaluated to detect buckled regions. The purpose of this research is to evaluate the sensitivity of the fiber-optic sensing system to buckling of a long structural member. Numerous facets of fiber-optic sensing have been explored. Fiber-to-steel bonding techniques were examined and tested. Full-scale laboratory testing was conducted by elastically buckling a 24.4-m-long (80-ft) wide-flange section with hydraulic rams. Typical measurement accuracy within 10 percent of theoretical predictions was achieved by optical time domain reflectometry techniques. For field testing, however, a more robust solution is sought and is currently under development. It is suggested that a lower-cost fiber break or bend detector is a suitable option. The optical fiber will break or bend at the location of rail elongation in the buckled area, allowing the detection equipment to locate the buckled area.

scholarly journals Localization and Discrimination of the Perturbation Signals in Fiber Distributed Acoustic Sensing Systems Using Spatial Average Kurtosis

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2839 ◽  
Author(s):  
Fei Jiang ◽  
Honglang Li ◽  
Zhenhai Zhang ◽  
Yixin Zhang ◽  
Xuping Zhang
Keyword(s):  
False Alarm ◽  
Signal To Noise Ratio ◽  
Moving Average ◽  
Spatial Dimension ◽  
Time Domain Reflectometry ◽  
Spatial Average ◽  
Acoustic Sensing ◽  
Sensing Systems ◽  
Distributed Acoustic Sensing ◽  
Optical Time

Location error and false alarm are noticeable problems in fiber distributed acoustic sensing systems based on phase-sensitive optical time-domain reflectometry (Φ-OTDR). A novel method based on signal kurtosis is proposed to locate and discriminate perturbations in Φ-OTDR systems. The spatial kurtosis (SK) along the fiber is firstly obtained by calculating the kurtosis of acoustic signals at each position of the fiber in a short time period. After the moving average on the spatial dimension, the spatial average kurtosis (SAK) is then obtained, whose peak can accurately locate the center of the vibration segment. By comparing the SAK value with a certain threshold, we may to some degree discriminate the instantaneous destructive perturbations from the system noise and certain ambient environmental interferences. The experimental results show that, comparing with the average of the previous localization methods, the SAK method improves the pencil-break and digging locating signal-to-noise ratio (SNR) by 16.6 dB and 17.3 dB, respectively; and decreases the location standard deviation by 7.3 m and 9.1 m, respectively. For the instantaneous destructive perturbation (pencil-break and digging) detection, the false alarm rate can be as low as 1.02%, while the detection probability is maintained as high as 95.57%. In addition, the time consumption of the SAK method is adequate for a real-time Φ-OTDR system.

scholarly journals Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

2017 ◽  
Vol 398 ◽  
pp. 95-100 ◽  
Author(s):  
Mingjia Shangguan ◽  
Chong Wang ◽  
Haiyun Xia ◽  
Guoliang Shentu ◽  
Xiankang Dou ◽  
...  
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Dynamic Strain ◽  
Fast Detection ◽  
Double Edge ◽  
Optical Time Domain Reflectometry ◽  
Optical Time
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