POTDR分布式光纤传感及其在安防监测中的应用

Distributed Fiber-optic Intrusion Sensor System Based on POTDR

提出了一种基于偏振光时域反射计分布式光纤传感技术的新型安防监测系统.该系统使用偏振分束器获取到具有正交偏振态的两路偏振光时域反射计信号,对比验证以确认是否出现了造成偏振态变化的扰动,提高了系统对扰动远程定位检测的准确度,大幅度减小了误判率和漏报率.同时在偏振光时域反射计系统的扰动探测中创造性的采用差值法和相对坐标相结合的方法,首次可以明显并且直观地检测和定位偏振光时域反射计系统中的扰动.最后采用Visual C++开发了一套实时的数据采集与处理软件.实验结果表明该系统具有较高的灵敏度,并在2km和14km处获取到具有较高信噪比的扰动信号.

A novel distributed optical fiber sensing system,based on a polarization optical time domain reflectometer （POTDR） technique setup,is demonstrated for detecting and locating intruders.The orthogonal polarizations of the backscattered light are monitored with a polarization beam splitter （PBS） and two identical receivers,and work together to detect the polarization perturbations of the returned light pulses.Such an approach can enhance the detection accuracy of perturbations and hence reduce the error rate simultaneously.The POTDR phenomenon is detecting obviously and easily by utilizing subtraction and relative coordinates,In the meanwhile,the data acquisition and analysis software for POTDR,is developed with the tool of Visual C＋＋.Experimental results show that a high SNR of the sensor signal at 2 km and 14 km along the fiber link achieved.