基于小波阈值降噪的长距离BOTDR测温系统研究  

Long-distance BOTDR temperature sensing system using wavelet threshold denoising

作　　者：于永胜 白清 蒋心雄 王宇 刘昕 靳宝全 YU Yongsheng;BAI Qing;JIANG Xinxiong;WANG Yu;LIU Xin;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;Shanxi Transportation Technology Research&Development Co.,Ltd.,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]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6期737-744,共8页Optical Technique

基　　金：国家自然科学基金(61975142,62005190);山西省重点研发计划项目(202102130501021);山西省科技创新人才团队专项(201805D131003);中国博士后科学基金资助项目(2021M691989)。

摘　　要：针对长距离布里渊光时域反射仪(BOTDR)存在的精度较低问题,提出基于探测光功率优化和小波阈值降噪的长距离BOTDR测温系统。通过分析光纤本征布里渊频移下时序曲线末端信噪比实现长距离BOTDR探测功率最优匹配,结合小波阈值降噪提高测温精度,在63km光纤上进行验证。实验结果表明,30m空间分辨率下,小波阈值结合探测功率优化使变温区布里渊频移波动从22MHz降至10MHz,重复性实验中光纤末端变温区温度波动为±5.3℃,温度波动均方根误差(RMSE)小于1.68℃,定位均方根误差(RMSE)小于1.78m。最后探索了不同空间分辨率下最优探测功率和光纤末端布里渊频移精度。研究表明,小波阈值降噪结合探测功率优化可有效提升长距离BOTDR系统的测温精度。To improving the accuracy of Brillouin Optical Time Domain Reflectometer(BOTDR)in long-distance temperature sensing,the detection optical power optimization and wavelet threshold denoising for long-distance BOTDR temperature sensing are proposed.By analyzing the SNRE at the end of the timing curve under the intrinsic Brillouin frequency shift,the detection optical power optimization of BOTDR is achieved,while combining wavelet threshold denoising algorithm to improve the temperature measurement accuracy.The experimental results demonstrate that the range of Brillouin frequency shift fluctuation is decreased from 22MHz to 10MHz in the temperature region by the wavelet threshold denoising.Moreover,the temperature fluctuation of end temperature region is between±5.3℃.In repeated measurement,the Root Mean Square Error(RMSE)of temperature fluctuation is less than 1.68℃ and the RMSE of localization is less than 1.78m.The detection optimal power and Brillouin frequency shift accuracy at the end of the fiber were explored under different spatial resolutions.This research results indicate that the accuracy of long-range BOTDR systems can be improved by wavelet threshold noise reduction combined with detection optical power optimization.

关 键 词：分布式光纤传感 BOTDR 小波阈值降噪 长距离温度解调 

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]