Method for improving intrusion event identification accuracy based on phase-sensitive optical time domain reflectrometer (phi-OTDR)

Abstract

The invention discloses a method for improving intrusion event identification accuracy based on a phase-sensitive optical time domain reflectrometer (phi-OTDR). The method includes the steps of 1), data acquisition; 2), single-point historical judgment; 3), regional vibration group judgment. The method is characterized in that the single-point historical judgment and the regional vibration group judgment are combined, M-frame real-time data detected by a phi-OTDR data acquisition system before current time are taken as analyzing samples, two steps of judgment are performed, and the single-point historical judgment removes thresholds to extract first-step characteristic quantity through adaptive mean values from the angle of variation amplitude of the M-frame real-time data before the current time; the regional vibration group judgment further extracts vibration characteristic quantity, namely the final vibration characteristic quantity, on the basis of the first-step characteristic quantity. The method has the advantages that the vibration characteristic quantity is extracted from the angles of a time domain and a spatial domain, intrusion event identification accuracy can be greatly improved, and meanwhile, engineering application requirements on timeliness is met, simpleness in calculation is achieved, and positioning stability is good.

Description

technical field [0001] The invention relates to a method for identifying an intrusion event by a phase-sensitive optical time-domain reflectometer, in particular to a method for improving the accuracy of identifying an intrusion event by a phase-sensitive optical time-domain reflectometer. Background technique [0002] Optical fiber sensing technology is a new type of sensing technology, which has the advantages of high measurement accuracy, anti-electromagnetic interference, intrinsic safety, distributed measurement, etc. It can be used to monitor and protect borders, military bases, power plants, oil pipelines, nuclear facilities and Prisons and other important areas and places. The distributed optical fiber vibration sensing system is based on the phase-sensitive optical time domain reflectometer (phase-sensitive optical time domain reflectrometer, namely ) principle, can realize the detection and positioning of multiple vibration events in different positions, only nee...

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Problems solved by technology

[0005] 2. Wavelet denoising method (Zengguang Qin, Liang Chen, Xiaoyi Bao. Wavelet Denoising Method for Improving Detection Performance of Distributed Vibration Sensor [J]. IEEE PHOTONICS TECHNOLOGY LETTERS, 2012, 24(7): 542~544): yes Filter out background noise and system noise, but this method has limited accuracy in identifying intrusion events;

[0007] 4. Detection methods based on time series singular spectrum features (Li Xiaoyu, Wu Huijuan, Peng Zhengpu, etc. Based on time series singular spectrum features Disturbance detection method [J]. Acta Photonica Sinica, 2014, 43(4): 0428001-1~0428001-5): Only analyze the signal change characteristics from the time domain, and the algorithm is complex

[0011] (3) The complexity of the algorithm: Whether the algorithm is complex or not not only affects the difficulty of implementing the actual engineering application of the algorithm, but also affects the real-time performance of the algorithm;

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