Method for identifying and detecting disturbance signals of phase-sensitive optical time domain reflectometer

Abstract

The invention discloses a method for identifying and detecting disturbance signals of a phase-sensitive optical time domain reflectometer. The method mainly aims at improving detection and intelligent identification ability of the phase-sensitive optical time domain reflectometer to external disturbance, and reducing a misstatement rate and a false alarm rate of a system in a practical complicated noise environment. The method comprises the steps that longitudinal time sequence signals of various spatial points serve as processing objects; fractal characteristics of the longitudinal time sequence signals are extracted for disturbance detection and positioning; multi-scale decomposition is conducted on the time sequence signals by wavelet transformation; the energy characteristics of detail signal components under different scales are extracted by utilizing distribution differences of the different-type disturbance signals of time-varying interference signals such as fluctuating background noises and sound waves, real intrusion signals and the like on a multi-scale time frequency shaft; multi-scale time frequency distribution characteristic vectors of the signals are formed; and specific attributes of the disturbance signals are identified and classified by combining a back-propagation (BP) neural network identification method. The method is applicable to application fields of perimeter security and protection, long-distance pipeline security, large-scale structure health monitoring and the like.

Description

technical field [0001] The invention relates to the fields of perimeter security, long-distance pipelines and large-scale structure safety monitoring, in particular to a method for detecting and identifying disturbance signals of a phase-sensitive optical time domain reflectometer. Background technique [0002] Phase-sensitive optical time domain reflectometry (Phase-sensitive optical time domain reflectometry, Φ-OTDR) is a typical fully distributed optical fiber sensing technology with high sensitivity, passive throughout, and can continuously sense dynamic parameters such as strain and vibration on the transmission path The spatial distribution and time change information of the system, because the detection distance and multi-point simultaneous positioning ability are significantly better than other interference technologies, it is often used as the first choice for long-distance fence technology applications, in perimeter security, long-distance oil and gas pipeline safet...

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Problems solved by technology

[0004] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a phase-sensitive optical time-domain reflectometer disturbance signal detection and identification method, which solves the problem that the existing system is sensitive to various interferences from the external environment and has a high false alarm rate. question

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