Distributed Fiber Vibration Sensing Network Based Perimeter Security System

Intelligent perimeter security system is an important application of Internet of Things in the security field. Multi-defending area detection, large monitoring range, long detection distance, high sensitivity, low false alarming rate, high anti-jamming capacity, high cost performance, easy to operate, manage and maintain are new demands of current security field to intelligent perimeter security systems. Because of the advantages of excellent electrical insulation, anti-electromagnetic interference, corrosion resistance, stable chemical property, compact size, light weight, variable geometric figure, low transmission loss, large transmission capacity, wide measuring range and so on, fiber sensors are especially suitable to be applied in the intelligent perimeter security systemPerimeter security technique based on distributed fiber vibration sensing network is studied in this dissertation and its application value is also discussed. The main research achievements are described as follows:(1) The concept of HSPON(Hybrid Sensing Passive Optical Network)is presented. Based on this concept, distributed fiber vibration sensing network based perimeter security system is constructed and perimeter monitoring with large capacity, long distance and wide range is achieved. Network based structure is in favor of the centralized monitoring, management and maintenance. Passive sensing unit improve the reliability and stablity of the system.(2) An unsymmetrical Mach-Zehnder/Sagnac interference sensing unit suitable for HSPON is represented. The new type of sensing unit avoids the insensitivity in the center of symmetry of normal Sagnac interferometer and stringent requirement to laser linewidth of normal Mach-Zehnder interferometer, improve the sensitivity of the perimeter management system.(3) The pulse modulated multi-wavelength light source of HSPON is based on the splitting of high performance wide spectrum light source and the amplifying of the seed light source. Due to its wavelength stability, high modulation frequency, high output power and stable comprehensive performance, it is particularly suited for HSPON.(4) Using PIN-FET array, the receiving and acquiring of multi-channel signals is achieved. The software designed for data processing and user management has complete fuctions including data acquisition, analysis processing and alert output.(5) Through practical experiments of HSPON, the main parameters of the system are analized and the experiment results show that the desired effect has been reached.HSPON based perimeter security system presented in this dissertation has wide application prospects in many domains such as national defense, mines and factories, community security, and has the ability to replace traditional techniques and become the mainstream in the development of perimeter management in intelligent communities.