基于光频域反射和互相关算法的分布式振动传感系统

Distributed Vibration Sensing System Based on Optical Frequency Domain Reflectometry and Cross-Correlation Algorithm

基于光纤中瑞利散射的特性,在光频域反射(optical frequency domain reflectometry, OFDR)系统中通过对信号进行互相关分析可以实现振动信号的分布式测量.在基于互相关算法的OFDR分布式光纤振动传感系统中,采用了重叠的移动窗对信号进行分段,并通过实验对比选取了合适的广义互相关算法的加权函数.实验表明,所提方法提高了系统的定位精度,降低了虚警率.系统的定位精度可达0.247 m,可测振动频率范围为5~50 kHz.

Based on characteristics of Rayleigh scattering light,one can achieve distributed measurements based on the correlation analysis of signals in the optical frequency domain reflectometry(OFDR)system.In this paper,we propose to apply overlapped sliding window in the subsections of signals and choose appropriate weighted function of generalized cross-correlation algorithm through experimental comparison in an OFDR distributed fiber-optic vibration sensing system based on cross-correlation algorithm.Experimental results show that by using the proposed technique,the OFDR performs with an improved positioning accuracy and a reduced false alarm rate.Furthermore,a distributed vibration sensor with the positioning accuracy of 0.247 m and the measurable vibration frequency ranging from 5 kHz to 50 kHz is demonstrated.