Positioning method and system of Sagnac fiber distributed vibrating sensor

Abstract

The invention discloses a positioning method and system of a fiber distributed vibrating sensor based on a Sagnac interference theory. The system comprises a wavelength or frequency tunable laser, a Sagnac ring composed of optical fibers, a detector and a signal processing module. The method comprises the following steps that: the Sagnac interference ring composed of the optical fibers is arranged close to a to-be-detected point as a sensing element to perform real-time monitoring; when vibration happens, the light emitted by the tunable laser is injected into the Sagnac ring by a coupler; two beams of lights which have different frequencies and carry vibrating position information transmit clockwise and anticlockwise respectively in the Sagnac ring simultaneously and meet at the detector end; the interference output electrical signal is received by the detector and vibration positioning is performed according to the relation between the output signal and the vibration position. The single light supplier, the single optical fiber and the single detector are adopted to replace the complex structure of multiple light suppliers, multiple optical fibers and multiple detectors of the traditional positioning systems, thus the system is simpler and easier to realize. The system is applicable to safety early-warning for long-distance and large-area important safety territory.

Description

technical field [0001] The invention relates to the field of optical fiber vibration sensing, in particular to a distributed optical fiber vibration sensor positioning method and system capable of locating vibration points. Background technique [0002] With the progress of human society, the number of important security areas such as airports, prisons, oil depots, power stations, long-distance oil and gas pipelines, and high-voltage transmission lines is increasing, and the number of illegal intrusion incidents is also increasing sharply. Preventing illegal intrusion has become an important issue of national and social concern. These fields have the characteristics of large area and long distance. When an intrusion occurs, it is the focus of security monitoring to locate the intrusion point and report to the police in time. [0003] The traditional security prevention methods that have been installed and used, such as access control, video surveillance, manual inspection, ...

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Problems solved by technology

However, it is precisely because of the addition of optical fibers, light sources or detectors that...

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