The Application Of P-OTDR In Power Cable And The Railway In The Security Perimeter

With the development of society,the demand of security is getting higher and higher, and there is a significant increase in the research of intrusion detection and sensing system in the whole world. The communication department needs real-time intrusion monitoring and fault diagnosis for its own communication building and communication optical cable. The departments of transportation in order to increase the protection of passengers, assets and infrastructure, the train station, railway perimeter,tunnel and so on. Oil and gas industry monitor the state of the transport pipeline, to preventing the pipeline from damaged. Even the national borde-line is equipped with an intrusion detection system to prevent illegal elements from entering the country. In the above circumstances, the intrusion detection system can avoid sacrifice, protect the property from theft or destruction.Traditional intrusion detection techniques such as human guard, impulse type electronic fence, microwave sensor, ultrasonic sensor alarm, string sensor, active infrared alarm and so on,have some deficiencies or environmental restrictions.Distributed fiber vibration sensing technology uses the transmission characteristics of the fiber, every point on the fiber as a sensor unit and then achieve the purpose of full distributed monitoring. The optical fiber is the sensing unit and the signal transmission medium, which has the advantages of simple structure, easy deployment and anti electromagnetic interference, and can be continuous monitoring of the space. Therefore,distributed optical fiber sensing technology has a good prospect in long-distance perimeter security, transmission cable, submarine cable and other safety monitoring.The main work of this paper includes the following aspects:Fiber as a sensor unit, as well as a signal transmission medium, simple structure,easy to deploy, anti-electromagnetic interference, and can be continuous monitoring of space in the long-range perimeter security, transmission cables, submarine cable and other safety monitoring very good application prospects.First, study the distributed fiber vibration sensing mechanism. (The mechanism of the interaction between vibration and fiber, the Rayleigh scattering phenomenon and its principle, and the Rayleigh scattering effect based on the optical time domain reflection sensor system analysis).Second, we designed and implemented the perimeter security monitoring system based on P-OTDR(polarization optical time domain reflectometer), and the parameters of the system calculated by combining theory and experiment.Third, multi-channel perimeter security monitoring system and application in the safety monitoring of power communication cable, based on Visual C ++ to achieve disturbance monitoring system alarm software and RFID pipeline positioning technology and SMS cat to achieve the line inspection and real-time SMS alarm function.Last, study on Application of Perimeter Security Monitoring System in Railway Perimeter Security Monitoring. Based Visual C ++ to achieve disturbance monitoring system alarm software, and linkage video surveillance and SMS cat wireless communication and other functional modules. To achieve comprehensive, visual integrated monitoring.