A novel FBG-based security fence enabling to detect extremely weak intrusion signals from nonequivalent sensor nodes

An intrusion detection method is proposed based on the autocorrelation characteristics of the signal with and without disturbances in an FBG-based fiber-optic fence. This technique is very effective to detect the extremely weak intrusion signal while it need not critical equivalent noise power or the same sensitivity or performance for all of sensor nodes in a large sensing network. And it can be easily used for a long perimeter with several fences of different materials and structures or a large security system inspecting multiple remote separated areas. The experimental results show the probability of detection (PD) of the fiber fence using this method for the single and multiple event detection can be both higher than 99.5%.