A Fast Early Warning Method Based on Phase Sensitive Optical Time Domain Reflectometer

Abstract

A rapid early-warning system based on a phase-sensitive optical time-domain reflectometer includes a disturbance monitoring and positioning module, and a disturbance signal identifying module. The disturbance monitoring and positioning module: a disturbance monitoring part performs difference on the beat signal intensity of a phase-sensitive optical time-domain reflectometer, the rapid early-warning system based on the phase-sensitive optical time-domain reflectometer can monitor the difference of the beat signal intensity all the time, and once the difference of the beat signal intensity changes, it means that a disturbance signal generated by disturbance occurs; and a positioning module can determine position information of a disturbance point through the time difference of an optical time-domain reflectometer echo. The disturbance signal identifying module includes a pre-treatment module, a feature extraction module, a template training module, a pattern classification module, and a post-treatment module; template training means that templates of a plurality of types of signals can be constructed according to features of a series of different types of disturbance signals; the features of the disturbance signals and preset templates of the plurality of types of signals are matched, and the types of the signals can be determined according the matching degrees; and a warning measure or a no-warning measure can be preformed according to a result of pattern classification.

Description

technical field [0001] The invention relates to the field of perimeter security optical fiber phase-sensitive optical time-domain reflectometer, in particular to a rapid early warning based on the phase-sensitive optical time-domain reflectometer. Background technique [0002] Phase-sensitive optical time domain reflectometer (Φ-OTDR) is a new type of distributed optical fiber sensor, which can monitor the vibration signal in a certain range along the optical fiber remotely and in real time. At the same time, the proposed phase demodulation method makes Φ-OTDR OTDR realizes quantitative measurement. The phase demodulation accuracy is as high as 0.1rad, which ensures the accuracy of subsequent pattern recognition. In Φ-OTDR, a series of pulsed probe light is injected into the sensing fiber, and its echoes are coherently detected and demodulated. The position of the disturbance point is determined by the return time of the echo; the disturbance information is reflected in th...

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Problems solved by technology

[0009] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to propose a fast warning system and method based on phase-sensitive optical time-domain reflectometer, in order to break through the development of current phase-sensitive optical time-domain reflectometer in the fields of intrusion detection and early warning. Faced with key problems such as time-consuming calculation, complex technology, and many requirements for training templates

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