基于布里渊增益谱二维图像小波阈值降噪的BOTDR测量精度提升研究  

Research on BOTDR measurement accuracy improvement based on two-dimensional image wavelet threshold denoising of brillouin gain spectrum

作　　者：王杨涛 白清 姚志玺[1,2] 王璇 王宇 靳宝全[1,2] WANG Yangtao;BAI Qing;YAO Zhixi;WANG Xuan;WANG Yu;JIN Baoquan(Key Laboratory of Advanced Transducers and Inteligent Control System of Ministry of Education and sanxi Province,Taiyuan University of technology,Taiyuan 030024,China;College of Electronic Information and Optical Engineering,Taiyuan University of technology,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与山西省重点实验室,山西太原030024 [2]太原理工大学电子信息与光学工程学院,山西太原030024

出　　处：《光学技术》2024年第5期619-625,共7页Optical Technique

基　　金：国家自然科学基金青年项目(62005190);山西省重点研发计划项目(202202130501004,202102130501021);山西省基础研究计划资助项目(202303021221032);中央引导地方科技发展资金项目(YDZJSX20231B004)。

摘　　要：针对布里渊光时域反射仪(BOTDR)信号弱,噪声干扰造成的测量精度降低问题,提出基于布里渊增益谱二维图像小波阈值降噪方法实现BOTDR系统测量精度提升。分析了微波扫频法BOTDR测量原理及二维布里渊增益谱图像特征,设计了二维图像小波阈值降噪算法流程,搭建了微波扫频法BOTDR实验装置进行降噪性能验证,基于降噪性能对比确定了二维小波基函数、分解层数、阈值规则及阈值函数最优参数匹配方案。实验结果证明,使用二维图像小波阈值降噪算法,在累加平均500次条件下,降噪前后10km传感光纤末端变温区布里渊频移波动范围由±4.61MHz降至±2.59MHz,均方根误差由2.24MHz降至0.99MHz;降噪前后50km传感光纤末端变温区布里渊频移波动范围由±41.25MHz降至±2.83MHz,均方根误差由33.59MHz降至1.69MHz。研究表明,使用该降噪方案可有效提升BOTDR测量精度。Aiming at the problem of weak signal and reduced measurement accuracy caused by noise interference in Brillouin Optical Time Domain Reflectometer(BOTDR), a wavelet threshold denoising method based on Brillouin gain spectrum two-dimensional image is proposed to improve the measurement accuracy of BOTDR system. Analyzed the principle of microwave frequency sweep BOTDR measurement and the characteristics of two-dimensional Brillouin gain spectrum image, designed a two-dimensional image wavelet threshold denoising algorithm flow, built a microwave scanning frequency BOTDR experimental device for denoising performance verification, and determined the optimal parameter matching scheme for two-dimensional wavelet function, degrade level, threshold regulation, and threshold function based on noise reduction performance comparison. The experimental results show that using the two-dimensional image wavelet threshold denoising algorithm, under the condition of accumulating an average of 500 times, the Brillouin frequency shift fluctuation range of the 10km sensing fiber end temperature range before and after denoising is reduced from ±4.61MHz to ±2.59MHz, and the root mean square error is reduced from 2.24MHz to 0.99MHz;Before and after noise reduction, the Brillouin frequency shift fluctuation range of the 50km sensing fiber end temperature range decreased from ±41.25MHz to ±2.83MHz, and the root mean square error decreased from 33.59MHz to 1.69MHz. Research has shown that using this noise reduction scheme can effectively improve the accuracy of BOTDR measurement.

关 键 词：分布式光纤传感 BOTDR 布里渊增益谱 布里渊频移 二维图像小波阈值降噪 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]