Fiber breakage positioning method for phi-OTDR distributed optical fiber sensing system

Abstract

The invention discloses a fiber breakage positioning method for a phi-OTDR distributed optical fiber sensing system, which comprises the steps of acquiring sample data, and establishing a least squaremethod data model; taking the distance from a starting point to an end point when the optical fiber is not broken as a standard distance, and acquiring signal intensities inside and outside the standard distance in the sensing system as process data and process quality data respectively; calculating according to the process quality data to obtain a fiber breakage judgment threshold; obtaining a fiber breakage judgment variance according to the process data in a window at the tail end of the standard distance; when the fiber breakage judgment variance is less than the fiber breakage judgment threshold, sliding the window forwards to obtain a current window, and solving a positioning variance according to the process data in the window; when the positioning variance is greater than the fiber breakage judgment threshold TH, searching first process data greater than the maximum value of the process quality data from the tail end of the window in an inverted order, and taking a position point corresponding to the process data as a fiber breakage position point, and otherwise, continuing to slide the window. According to the invention, the fiber breakage position point can be accuratelyand rapidly found.

Description

Technical field [0001] The invention relates to the technical field of distributed optical fiber sensing, in particular to a fiber breakage positioning method of a φ-OTDR distributed optical fiber sensing system. Background technique [0002] The distributed optical fiber sensing system uses optical fiber as the detection carrier and laser as the detection signal. Due to the continuity of the detection signal and the optical fiber, it can obtain information about the spatial and temporal changes of the measured parameters over the entire fiber length. Distributed optical fiber The sensing system can realize long-distance monitoring, with mature technology and wide application, and has a very important position in the field of optical fiber sensing monitoring; the distributed optical fiber sensing system based on phase sensitive optical time domain reflectometer (Φ-OTDR) has The advantages of high positioning accuracy and multi-point detection, simple system structure, system sta...

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Problems solved by technology

[0003] At present, there are mainly two ways to locate fiber breaks: (1) find the access port of the broken fiber line through the detection of engineering maintenance personnel; (2) perform multiple average calculations based on the signal strength within one optical pulse cycle and calculate the average value multiple times Comparing with the preset threshold value to get the fiber break position of the system; the first method is time-consuming and labor-intensive, the work is cumbersome and inefficient; A method capable of solving such problems

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