随机数编码融合长脉冲级联调制提升Φ-OTDR定位性能  

Random coding method fused with long-pulse cascade modulation forΦ-OTDR localization performance improvement

作　　者：苏玉文 王宇 樊迎瑞 白清 刘昕 靳宝全 SU Yuwen;WANG Yu;FAN Yingrui;BAI Qing;LIU Xin;JIN Baoquan(Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Transportation Technology Research&Development Company Limited,Taiyuan 030024,China)

机构地区：[1]太原理工大学新型传感器与智能控制教育部重点实验室,山西太原030024 [2]山西省交通科技研发有限公司,山西太原030024

出　　处：《光学技术》2024年第3期354-360,384,共8页Optical Technique

基　　金：山西省重点研发计划项目(202102130501021);中央引导地方科技发展资金项目(YDZJSX20231B004);山西省科技创新团队项目(201805D131003)。

摘　　要：为解决随机数编码造成相位敏感光时域反射系统振动定位差的问题,设计了一种随机数编码融合长脉冲的级联调制方法,分别利用声光调制器和半导体光放大器实现随机数编码和长脉冲的融合调制,提升消光比。使用自相关的随机数编码生成脉冲序列,设计数字正交解调算法获得拍频信号幅值与相位信息。实验结果表明,在4km长度传感光纤上,脉冲宽度为40ns时,方案可将消光比提升13.7dB;当振动信号频率为200Hz时,振动信号定位均方根误差为2.1m,最大绝对误差为3.8m,提升了振动信号定位精度,为编码相位敏感光时域反射系统定位性能提升提供了新方法。In order to solve the problem of poor vibrational localization of phase-sensitive optical time-domain reflectometer(Φ-OTDR)system caused by random coding method,a cascade modulation method of random code fused with long pulse is proposed.The acousto-optic modulator and semiconductor optical amplifier are used to realize the fusion modulation of random code and the long pulse,respectively,to improve the extinction ratio.The autocorrelation random code is used to generate the pulse train,and the digital quadrature demodulation algorithm is designed to obtain the beat frequency signal amplitude and phase information.The experimental results show that the scheme can improve the extinction ratio by 13.7dB with 40 ns-width pulse and 4 km-length sensing fiber.When the vibration signal frequency is 200Hz,the root-mean-square error of the vibration signal localization is 2.lm,and the maximal absolute error is 3.8m,which improves the vibration signal localization accuracy.The research provides a new method for the localization performance enhancement of the coded Φ-OTDR system.

关 键 词：光纤传感 相位敏感光时域反射仪 随机数编码融合长脉冲 消光比 振动信号定位 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]