设计了一种基于弱光纤布拉格光栅阵列的增强相位敏感光时域反射仪(-OTDR)振动传感系统，以反射率较大的弱光纤光栅反射信号代替-OTDR中的瑞利散射信号，利用相邻弱光纤光栅反射信号间干涉信号的强度变化来判断光纤线路上振动事件的情况，并采用时分复用技术对振动点进行精确定位。结果表明，该系统在面向振动信号的检测与解调方面比-OTDR更为简便，同时能实现分布式测量，并能解调出频率范围为10～500 Hz的任意振动信号，在周界安防领域具有实际应用价值。

An enhanced phase sensitive optical time-domain reflectometer (-OTDR) vibration sensing system based on weak fiber Bragg grating arrays is designed. A weak reflection signal from the fiber Bragg grating (FBG) with a relatively large reflectivity is used instead of the Rayleigh scattering signal in the -OTDR system. The perturbation behaviors in the optical fiber lines are determined based on the intensity variation of the interference signal between the adjacent weak FBG reflection signals and the time division multiplexing technique is used to locate external vibration points precisely. The results show that, by this system, the detection and demodulation of the vibration signal are simpler than those by -OTDR, the distributed measurement is simultaneously fulfilled, and any vibration signals in the frequency range of 10-500 Hz can be demodulated. The system has the practical application value in perimeter surveillance systems.