双马赫-曾德尔分布式光纤扰动监测系统设计

为解决扰动监测系统定位精度低的问题, 基于对光纤马赫-曾德尔干涉的研究, 设计了改进型双马赫-曾德尔分布式光纤扰动监测系统。 利用双马赫-曾德尔光纤传感系统光程差定位原理, 通过互相关算法估算光程差导致的时间差确定扰动点。 淹没于高频噪声的扰动信号经自主设计的信号预处理电路, 采用低通巴特沃斯滤波器滤除 3. 3 kHz 以上高频噪声, 通过嵌入式采集与处理模块对得到的数据进行平滑滤波, 提高了扰动信号的相关性, 有效减小了定位误差。 通过多次重复测试和数据分析结果表明, 系统定位误差约为10 m, 可用于扰动实时监测。

Design of Disturbance Monitoring System Based on Dual Mach-Zehnder Distributed Optical Fiber Sensing

In order to solve the problem of low positioning accuracy in disturbance monitoring system, an improved dual Mach-Zehnder distributed optical fiber sensing system is designed for real-time monitoring of disturbances,which is based on the study of Mach-Zehnder fiber interferometer.The optical path difference in the dual Mach-Zehnder optical fiber sensing system leads to the time difference,and then the system uses cross-correlation algorithm to estimate the time difference, to ensure the perturbation point.The independently designed the signal preprocessing circuit and filtering algorithm are realized through the Butterworth low -pass filter filtering the high-frequency noise that above 3.3 kHz.And via the embedded acquisition and processing module the correlation is improved and positioning error is reduced.After repeated tests and data analysis,it is shown that the system can be used for real-time disturbance monitoring and the positioning error is about 5 meters.