Intrusion detection and location method of distributed fiber optic fence based on φ-otdr

A distributed optical fiber, -OTDR technology, applied in the direction of instruments, anti-theft alarms, alarms, etc., can solve the problems of low signal-to-noise ratio of monitoring signals, large self-fluctuation, unstable optical system, etc., and achieve a wide range of monitoring distances , save system cost, cost-effective effect
CN102280001AInactive Publication Date: 2011-12-14UNIV OF ELECTRONICS SCI & TECH OF CHINA
3 Cites 20 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
UNIV OF ELECTRONICS SCI & TECH OF CHINA
Publication Date
2011-12-14
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a distributed optical fiber fence intrusion detection and location method based on a phi-OTDR (Optical Time Domain Reflectometer), and the method comprises the following steps of: firstly, subtracting an acquired ith signal by an acquired (i-1)th signal to obtain a preprocessing monitoring signal; secondly, carrying out at least four-layer wavelet decomposition on the preprocessing monitoring signal by adopting a plurality of wavelet functions; thirdly, judging whether actual intrusion exists according to the consistency of distribution positions of maximum-wavelet mode maximums in all scale signals; fourthly, judging that the actual intrusion exists if the distribution positions of the maximum-wavelet mode maximums in at least three scale signals are consistent; fifthly, corresponding multiplying the scale signals in which the intrusion exists and the distribution positions of the maximum-wavelet mode maximums are consistent to obtain a composite signal of which pseudo maximums are inhibited and mode maximums at a catastrophe point are enhanced, using a position corresponding to the maximum-mode maximum in the composite signal as a position of the determined intrusion point, determining the intrusion generation and the intrusion position by combining various composite signal judgment results of wavelet multi-scale analysis according to the majority voting criterion.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the field of perimeter security and distributed optical fiber sensing signal processing, in particular to a method for intrusion detection and positioning of distributed optical fiber fences based on Φ-OTDR. Background technique

[0002] Phase sensitive optical time domain reflectometer (Φ-OTDR) is a new type of distributed optical fiber sensing technology. The same as the conventional optical time domain reflectometer (OTDR), the optical pulse is injected from one end of the optical fiber, and after being detected by the detector, it scatters the light to Rayleigh to judge the disturbance and fault location; the difference is that the Φ-OTDR system injects a strong For coherent light, what is detected is the result of the interference of Rayleigh scattered light in the pulse width range. The position of the interference point can be judged by measuring the time delay between the input pulse and the received interference signal...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More