摘要
针对分布式振动传感中温度、应力等缓变因素导致的低频相位漂移,提出了一种基于新型相位载波(PGC)调制解调技术的双M-Z干涉仪型FDDS,原始信号经窄带模拟低通滤波后,再通过A/D转换器转变为数字信号完成解调,解决了传统数字PGC调制解调技术中因高速A/D采集而引入的窄带数字低通滤波的设计难题,通过构造特殊解调项实现了高次谐波解调,同时补偿了因长距离传感光纤引起的相位延时,提高了信噪比,最终达到抑制低频相位漂移、减小定位误差、提高定位精度的目的.
It is found that the phase drift induced by slow time-varying fluctuation such as temperature variation causes the location errors of FDDS.A phase drift insensitive Mach-Zehnder interferometer（M-Z）based on fiber-optic distributed disturbance sensor（FDDS）incorporating a novel phase generation carrier（PGC）technique is proposed and investigated.By means of a novel PGC technique,a narrow band analog low pass filter is designed,it solved the problem of facilitating the digital narrow band low pass filter in high speed A/D acquisition.Meanwhile,a special demodulation signal was designed to demodulate higher-order harmonic,compensated the time delay of the long optical fiber and enhanced the SNR.Finally low-frequency phase drift can be inhibited,the location error be reduced and the location accuracy be enhanced.
出处
《测试技术学报》
2014年第3期237-242,共6页
Journal of Test and Measurement Technology
关键词
光纤传感器
振动传感
相位载波
相位漂移
定位误差
optical sensors
disturbance measurement
phase generation carrier
phase drift
location error
