相敏型光时域反射系统信噪比提升  

Improvement of signal-to-noise ratio for phase-sensitive optical time-domain reflecting system

作　　者：王子豪 刘志凯 冯玉祥 张成龙 吕立冬 WANG Zi-hao;LIU Zhi-kai;FENG Yu-xiang;ZHANG Cheng-long;LV Li-dong(School of Electrical and Information Engineering,Anhui University of Technology,Maanshan 243002,China)

机构地区：[1]安徽工业大学电气与信息工程学院,安徽马鞍山243002

出　　处：《中国光学(中英文)》2025年第2期287-296,共10页Chinese Optics

基　　金：国家自然科学基金项目(No.51977001)。

摘　　要：相位敏感型光时域反射系统(Φ-OTDR)的灵敏度受激光器的相位噪声、掺铒光纤放大器的自发辐射噪声、光电探测器的散粒噪声及热噪声等系统固有噪声和环境随机噪声的制约,因此,本文研究光时域反射数据的降噪算法,在不降低系统频率响应范围的条件下提高系统的信噪比。本文提出Savitzky-Golay平滑算法,选择固定长度的滑动窗口,对窗口内的光时域反射数据进行降噪处理,同时保持数据的采样频率,并搭建实验系统进行验证。实验结果显示:采用Savitzky-Golay平滑算法,系统的信噪比相对于原始信号逐差法的信噪比提高了5.41 dB,与常用的累加平均算法、滑动平均算法相比信噪比分别提升3.39 dB和5.05 dB。结果表明:Savitzky-Golay平滑算法可提高Φ-OTDR系统的灵敏度和准确度,使其能够精准地感知微小振动事件,以降低系统误报率。The sensitivity of the phase-sensitive optical time-domain reflecting(Φ-OTDR)system is limited by the system’s intrinsic noise,such as the laser’s phase noise,the erbium-doped fiber amplifier’s spontaneous emission noise,and the photodetector’s shot and thermal noise,as well as random environment of noise.Therefore,we investigate the noise reduction algorithm based on the optical time-domain reflecting data to improve the system’s signal-to-noise ratio(SNR)without degrading its frequency response range.Furthermore,we propose a Savitzky-Golay smoothing algorithm by selecting a slidable fixed-length window to process OTDR data for the SNR improvement while maintaining the system sampling frequency.Then,we built the experimental system to demonstrate the results.The experimental results show that by using the Savitzky-Golay smoothing algorithm,the SNR of the system is improved by 5.41 dB relative to the difference method with the original data,and the SNR is improved by 3.39 dB and 5.05 dB,compared to the commonly used cumulative averaging method and sliding averaging method,respectively.It is demonstrated that the Savitzky Golay smoothing algorithm can improve the sensitivity and accuracy of theΦ-OTDR system,which helps to sense weak vibration events accurately and reduce false alarm rates.

关 键 词：相位敏感光时域反射仪 Savitzky-Golay平滑算法 信噪比 阈值定位 

分 类 号：TP212.9[自动化与计算机技术—检测技术与自动化装置] TN212[自动化与计算机技术—控制科学与工程]