Distributed Optical Fiber Of ¦µ-otdr Security Systems Practical

Φ-OTDR (Phase-Sensitive Optical Time-domain Reflectometry) distributed optic-fiber sensing system is a kind of distributed sensing system using optic-fiber as the sensing medium, and carries on real-time remote security monitoring of the target within it.Φ-OTDR distributed optic-fiber sensing system not only has the features of electromagnetic immunity, anti-eroding and sensitivity, but also takes advantages of hardly being revealed, precise alarm locating, easily data prcessing and so on. Such a distributed sensing system is anticipated to be used widely in safety monitoring of military bases, national boarders, nuclear facilities, electrical power generation stations, jails, et al.Φ-OTDR technology is an emerging technology in the recent years, there have some productions in the theoretical studying. Based on these conditions, our works began with the theoretical researching, then analyzed and discussed the practical application on the distributed optical fiberΦ-OTDR Security Monitoring System. The main works can be divided into the following specific aspects:(1) Analysis of the feasibility of distributed optical fiber sensing system solutions as well as its advantages and disadvantages, discussed and analysed the distributed optical fiber sensing system research and development of this research status. It showed that the distributed optical fiber system based onΦ-OTDR technology had significant economic value and social value.(2) Proposed new type of composite materials, which used in the fiber optic cable fiber-optic sensor system. From the basic characteristics of FRP composite material fiber optic cable, it's stress sensitivity has been investigated. This composite materials optic cable can be used for replacing the general cable as a sensor in the system has been demonstrationed by the experiments.(3) Introduction of the system used in the EDFA work characteristics and basic parameters, and analysis the existing laboratory lasers several advantages and disadvantages. AΦ-OTDR distributed optic-fiber sensing system based on a DFB laser was proposed. This system can locate the intrusion point, within a distance range of 12km, with the best spatial resolution of 50m, signal to noise ratio to achieve 5dB.(4) Using the DFB laser as light source, a special FRP encapsulated fiber cable for sensing medium, the laboratory and the field tests simulation experimental testing was conducted. The laboratory experimental comparison of the interior FRP composite materials with the general fiber optic cable atΦ-OTDR fiber-optic sensing system of the experimental results; the field experiment will achieve a composite material FRP in the 6-10cm fiber optic cable buried in soil as a sensing medium. This system can achieve within a distance range of 6km, with the best spatial resolution of 25m of distributed optical fiber sensing systems. Based on this result, its improves and perfects the distributed optical fiber sensing system utility function.