φ-OTDR识别不同频率振动事件研究

摘要

In monitoring intrusion incidents based on phase-sensitive Optical Time Domain Reflectrometer(φ-OTDR),the method compositing the past records of a single point and the data of neighboring points distinguishes intrusion from noise by the data change in a period and in neighboring area, and the system can locate the intrusion point where the optical intensity will change for the reason of interference. Based on this method, this paper is about a research on three parts, they are the threshold processing based on self-adaption mean value, analysis and simulation on frequency responses, and classifying the frequency information consists in the intrusion incidents. A group of experiments in 25 different frequencies confirm that the threshold has a good adaptability, the frequency responses agree with analysis and simulation, and the algorithm can classify the frequency information accurately. Therefore,this research will contribute to applyingφ-OTDR to security system.%在相位敏感光时域反射计(φ-OTDR)识别入侵事件中，时间域单点振动判断和空间域相邻点振动判断算法是以一段时间和相邻区域内的数据变化幅度为依据，来检测由入侵者产生的光强差异，定位入侵位置。本文在这种算法的基础上，重点研究了三个方面的内容：即研究自适应均值去阈值的方法、分析了该算法可以识别的振动事件的频率响应范围、设计算法对振动事件所包含的频率信息分类，并通过25组不同频率的振动实验验证算法和分析。实验证实研究出的阈值处理方法适应性非常好，频率响应范围与理论分析一致，且设计的频率分类算法能够实现对振动事件所包含的频率信息正确分类，为φ-OTDR的实际工程应用提供参考。