Research On Sensing Cable In Perimeter Intrusion Detection Sensor Based On BOTDR

Optical fiber sensing has great advantages over the traditional sensing techniques. Optical fiber sensing is researched by research institutes all over the world, as a result, more and more new applications are developed. In the 1990s, researchers applied fiber sensing technique into perimeter intrusion sensing and found fiber fence. Fiber fence system has overcome many drawbacks of the traditional perimeter intrusion sensor, such as short detection range, low sensitivity, easy affected by EMI, and realized long distance, distributed, high sensitivity, high location accuracy, low false alarm rate perimeter intrusion sensing. With the increasing demand of the perimeter security, fiber fence system will be widely applied.In this paper the properties of sensing cable in perimeter intrusion sensing system based on Brillouin Optical Time Doman Reflectometer(BOTDR) is researched.By building the theoretical model of sensing cables, this paper calculated the stress transfer capability of the sensing cable samples. After comparing the applicability of several types of sensing cable in the perimeter intrusion sensing system based on BOTDR, this paper chose the most suitable sensing cable, considering the application environment and the stress transfer capabilities. Meanwhile, by doing stress analysis of the cable on the fence combining the experimental data, this paper has established the best way to lay the sensing cable on the fence, including the laying position,.This paper analyzed the characteristics of both intrusion behaviors and non-intrusion behaviors, and distinguished the intrusion behaviors from non-intrusion behaviors by analyzing the testing data, which reduced the false alarm rate.This paper used the perimeter intrusion sensing system based on Brillouin Optical Time Doman Reflectometer to implement field test on a part of the railway fence and a part of residential area fence, the results showed this system can detect intrusion events correctly, it has high positioning accuracy, long detection range and short response time.