Aircraft Detection Using Phase-Sensitive Optical-Fiber OTDR

Aircraft detection plays a vital role in aviation management and safe operation in the aviation system. Phase-Sensitive Optical Time Domain Reflectometry (Φ-OTDR) technology is a prevailing sensing method in geophysics research, structure inspection, transportation detection, etc. Compared with existing video- or radio-based detection methods, Φ-OTDR is cost-effective, suitable for long-distance detection, and resistant to severe weather conditions. We present a detection system using Φ-OTDR technology and analyze the character of the acoustic signal of aircraft. Instead of runway monitoring in the airport or noise detection in the air, this study focuses on the detection of seismic vibration signal excited by the sound of aircraft. The Chebyshev filter is adopted to eliminate the impact of background noise and random noise from the original vibration signal; the short-time Fourier transform is used for time-frequency analysis. The experimental results showed that the seismic vibration signal excited by the aircraft sound is mainly low-frequency, which is under 5 Hz. Time delay of aircraft vibration signal in different locations of the optic fiber is recorded by the sensing system. The Doppler effect is also revealed by the time-domain analysis: the frequency increases when the aircraft is approaching and decreases when the aircraft moves away.

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Research and Software Design of an Φ-OTDR-Based Optical Fiber Vibration Recognition Algorithm

Journal of Electrical and Computer Engineering ◽

10.1155/2020/5720695 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Bernard Marie Tabi Fouda ◽

Dezhi Han ◽

Bowen An ◽

Xiangzhi Chen

Keyword(s):

Optical Fiber ◽

Monitoring System ◽

Time Domain ◽

Signal Transmission ◽

Vibration Signal ◽

Recognition Algorithm ◽

Time Domain Reflectometry ◽

Experimental Simulation ◽

Time Frequency ◽

Security Monitoring System

Distributed optical fiber vibration signal plays a significant role in the communication and safety of any perimeter security monitoring system. It uses light as an information carrier and optical fiber as a means of signal transmission and communication. Phase-sensitive optical time-domain reflectometry (Φ-OTDR) is used to detect the signals generated during events (intrusions or nonintrusion). This paper proposes the time-frequency characteristic (TFC) method for the recognition of the fiber vibration signal and designs and implements the corresponding software function module. The combination of time-domain features and time-frequency-domain features is called TFC; and it is based on the Hilbert transform and on the empirical mode decomposition (EMD) of time-frequency entropy and center-of-gravity frequency that is described. A feature vector is formed, and multiple types of probabilistic neural networks (PNNs) are performed on it to determine whether intrusion events occur. The experimental simulation results show that the monitoring system software can intelligently display the data collected in real time, which demonstrates that the proposed method is effective and reliable in identifying and classifying accurately the types of events. The data processing time is less than 2 s, and the accuracy of the system identification can reach 99%, which ensures the system’s validity.

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Long-distance distributed pressure sensing based on frequency-scanned phase-sensitive optical time-domain reflectometry

Optics Express ◽

10.1364/oe.425501 ◽

2021 ◽

Author(s):

Li Zhang ◽

Zhisheng Yang ◽

Lukasz Szostkiewicz ◽

Krzysztof Markiewicz ◽

Sergei Mikhailov ◽

...

Keyword(s):

Time Domain ◽

Time Domain Reflectometry ◽

Long Distance ◽

Pressure Sensing ◽

Optical Time Domain Reflectometry ◽

Phase Sensitive ◽

Optical Time ◽

Distributed Pressure

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Research Status of Distributed Optical Fiber Sensing System Based on Phase-sensitive Optical Time Domain Reflectometry

International Journal of Scientific and Research Publications (IJSRP) ◽

10.29322/ijsrp.9.05.2019.p89105 ◽

2019 ◽

Vol 9 (5) ◽

pp. p89105

Author(s):

Abdikarim Ahmed ◽

Zhihua Yu

Keyword(s):

Optical Fiber ◽

Time Domain ◽

Time Domain Reflectometry ◽

Fiber Sensing ◽

Sensing System ◽

Optical Time Domain Reflectometry ◽

Optical Fiber Sensing ◽

Phase Sensitive ◽

Optical Time ◽

Distributed Optical Fiber

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

Photonic Sensors ◽

10.1007/s13320-021-0619-4 ◽

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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Continuous Chirped-wave Phase-sensitive Optical Time-domain Reflectometry: Principles and Demonstrations

10.1109/icocn53177.2021.9563795 ◽

2021 ◽

Author(s):

Jialin Jiang ◽

Zinan Wang

Keyword(s):

Time Domain ◽

Time Domain Reflectometry ◽

Wave Phase ◽

Optical Time Domain Reflectometry ◽

Phase Sensitive ◽

Optical Time

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

Applied Sciences ◽

10.3390/app8101899 ◽

2018 ◽

Vol 8 (10) ◽

pp. 1899 ◽

Cited By ~ 3

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.

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