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Recognition of a Phase-Sensitivity OTDR Sensing System Based on Morphologic Feature Extraction.

Sun Q, Feng H, Yan X, Zeng Z - Sensors (Basel) (2015)

Bottom Line: In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal.Feature vectors are obtained from morphologic features of time-space domain signals.A scatter matrix is calculated for the feature selection.

View Article: PubMed Central - PubMed

Affiliation: Tianjin University, State Key Laboratory of Precision Measurement Technology & Instruments, 92 Weijin Road, Nankai District, Tianjin 300072, China. sunqiansohu@126.com.

ABSTRACT
This paper proposes a novel feature extraction method for intrusion event recognition within a phase-sensitive optical time-domain reflectometer (Φ-OTDR) sensing system. Feature extraction of time domain signals in these systems is time-consuming and may lead to inaccuracies due to noise disturbances. The recognition accuracy and speed of current systems cannot meet the requirements of Φ-OTDR online vibration monitoring systems. In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal. Feature vectors are obtained from morphologic features of time-space domain signals. A scatter matrix is calculated for the feature selection. Experiments show that the feature extraction method proposed in this paper can greatly improve recognition accuracies, with a lower computation time than traditional methods, i.e., a recognition accuracy of 97.8% can be achieved with a recognition time of below 1 s, making it is very suitable for Φ-OTDR system online vibration monitoring.

No MeSH data available.


Simplified construction of a Φ-OTDR system.
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sensors-15-15179-f002: Simplified construction of a Φ-OTDR system.

Mentions: The Φ-OTDR system has unique signal characteristics compared with other optic fiber sensing systems. Rayleigh Scattering (RS) light traveling within a fiber is phase modulated by vibrations that are applied to the fiber to acquire a RS curve for the pulse duration. The time-space domain signal is acquired by clustering all RS curves. It can reflect the characteristics in the space and time domain simultaneously. The propagation distance of vibrations in the space domain reflects the energy of the intrusion signal and the signal characteristics in the time domain reflect the duration of the intrusion event. A simplified construction of an Φ-OTDR system is shown in Figure 2. It can be assumed that that ε(t) is the optical pulse and L is the length of optical fiber. The vibration occurs at position z0 and the optical phase is therefore modulated by the vibration, with variation Φ.


Recognition of a Phase-Sensitivity OTDR Sensing System Based on Morphologic Feature Extraction.

Sun Q, Feng H, Yan X, Zeng Z - Sensors (Basel) (2015)

Simplified construction of a Φ-OTDR system.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541826&req=5

sensors-15-15179-f002: Simplified construction of a Φ-OTDR system.
Mentions: The Φ-OTDR system has unique signal characteristics compared with other optic fiber sensing systems. Rayleigh Scattering (RS) light traveling within a fiber is phase modulated by vibrations that are applied to the fiber to acquire a RS curve for the pulse duration. The time-space domain signal is acquired by clustering all RS curves. It can reflect the characteristics in the space and time domain simultaneously. The propagation distance of vibrations in the space domain reflects the energy of the intrusion signal and the signal characteristics in the time domain reflect the duration of the intrusion event. A simplified construction of an Φ-OTDR system is shown in Figure 2. It can be assumed that that ε(t) is the optical pulse and L is the length of optical fiber. The vibration occurs at position z0 and the optical phase is therefore modulated by the vibration, with variation Φ.

Bottom Line: In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal.Feature vectors are obtained from morphologic features of time-space domain signals.A scatter matrix is calculated for the feature selection.

View Article: PubMed Central - PubMed

Affiliation: Tianjin University, State Key Laboratory of Precision Measurement Technology & Instruments, 92 Weijin Road, Nankai District, Tianjin 300072, China. sunqiansohu@126.com.

ABSTRACT
This paper proposes a novel feature extraction method for intrusion event recognition within a phase-sensitive optical time-domain reflectometer (Φ-OTDR) sensing system. Feature extraction of time domain signals in these systems is time-consuming and may lead to inaccuracies due to noise disturbances. The recognition accuracy and speed of current systems cannot meet the requirements of Φ-OTDR online vibration monitoring systems. In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal. Feature vectors are obtained from morphologic features of time-space domain signals. A scatter matrix is calculated for the feature selection. Experiments show that the feature extraction method proposed in this paper can greatly improve recognition accuracies, with a lower computation time than traditional methods, i.e., a recognition accuracy of 97.8% can be achieved with a recognition time of below 1 s, making it is very suitable for Φ-OTDR system online vibration monitoring.

No MeSH data available.