Link self-diagnosis long-distance distributed fiber vibration monitoring system

Abstract

The invention relates to a link self-diagnosis long-distance distributed fiber vibration monitoring system. The monitoring system comprises a first light source module, a second light source module, a wave combiner module, an optical circulator, a wave division module, a light amplification module, a photovoltaic conversion and amplification filtering module, a data acquisition and processing module, an upper computer control and display module, an upper computer and a fiber to be measured. The first light source module and the second light source module are connected with the waver combiner module; the waver combiner module is connected with the optical circulator; the optical circulator is connected with the fiber to be measured and the wave division module; one output end of the wave division module is connected with the photovoltaic conversion and amplification filtering module, and the other output end is connected with the photovoltaic conversion and amplification filtering module through the light amplification module; and the photovoltaic conversion and amplification filtering module, the data acquisition and processing module, the upper computer control and display module and the upper computer are connected in sequence. The monitoring system can realize vibration event monitoring and accurate judgment and is long in detection distance, high in sensitivity and low in false alarm rate.

Description

technical field [0001] The invention relates to the technical field of optical fiber security, in particular to a link self-diagnosis long-distance distributed optical fiber sensing system for judging and locating optical fiber link attenuation and vibration events. Background technique [0002] On June 26, 2000, a serious case of oil drilling and theft occurred in the Daxing section of the Qinjing pipeline, losing 950,000 yuan worth of crude oil, and the leakage caused a direct economic loss of 3 million yuan and an indirect economic loss of 12.8 million yuan to the country; [0003] On July 21, 2003, the oil pipeline was artificially drilled near Exit No. 30 of the Jingjintang Expressway of the Qinjing Pipeline, causing a large amount of crude oil leakage, and the Qinjing Pipeline was suspended for 10 hours; [0004] On October 20, 2003, the Tieqin Oil Pipeline was destroyed by oil thieves near Sijiazi Village, Xinchengzi Township, Xinchengzi District, Shenyang, and a crud...

AI Technical Summary

Problems solved by technology

[0012] The existing oil and gas pipeline safety monitoring methods mainly include oil and gas pressure detection method, oil and gas flow detection method, negative pressure wave detection method, distributed optical fiber vibration measurement method based on coherent OTDR, etc. The first three monitoring methods can only reduce and control Losses caused by leakage cannot prevent man-made damage to pipelines

In addition, the existing short-distance distributed optical fiber vibration monitoring system can no longer meet the needs of early warning monitoring of tap water transmission pipelines, power transmission cables, and optical fiber communication backbone networks, as well as intrusion security monitoring of long-distance border lines and large-scale open perimeters.

[0013] Distributed optical fiber vibration measurement based on coherent OTDR has the advantages of being free from electromagnetic interference, corrosion resistance, and accurate alarm positioning, but it also has disadvantages such as short monitoring distance, inaccurate pattern recognition, high rate of false alarms and false alarms, and insufficient sensitivity. It can monitor some event points, such as breakpoint, loss, attenuation, etc., but because the backscattering curve of the monitoring vibration event introduces a modulation signal, it is impossible to perform multiple average processing when judging the event point, otherwise the vibration event point will be generated. False positives and false negatives

And it is impossible to accurately judge the event points such as loss, attenuation, breakpoint or twist of the optical fiber link

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