Ф-OTDR非平稳信号的连续时频域分析  

Continuous Time Frequency Domain Analysis ofФ-OTDR Nonstationary Signals

作　　者：徐涛 李黎[2] XU Tao;LI Li(Guangzhou Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Guangzhou 510000,China;School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430073,China)

机构地区：[1]广东电网有限责任公司广州供电局,广州510000 [2]华中科技大学电气与电子工程学院,武汉430073

出　　处：《哈尔滨理工大学学报》2021年第4期146-152,共7页Journal of Harbin University of Science and Technology

基　　金：国家自然科学基金(51777082).

摘　　要：多数自然振动为平稳信号,且受光纤分布式振动传感系统的干涉光信号调制。作为事件识别关键参量之一的幅值信息无法采用传统信号分析方法准确获得。本文基于分数阶傅里叶变换在统一的幅、时、频域内更准确地提取Phase-sensitive optical time domain reflectometry(Ф-OTDR)信号的幅值信息。在分析Ф-OTDR非平稳信号形成原因的基础上,进一步讨论分数阶傅里叶变换的适用条件,最后在实际地下电气管廊第三方破坏中检测分数阶傅里叶变换提取Ф-OTDR信号的幅值信息的有效性。分数阶傅里叶变换在连续的幅、时、频域分析中,更准确地提取非平稳振动信号的幅值信息,有助于Ф-OTDR事件探测与类型分析。Most of the natural vibration signals are stationary and modulated by the interference light signal of the distributed optical fiber vibration sensing system.As one of the key parameters of event recognition,amplitude information cannot be accurately obtained by traditional signal analysis methods.This paper used the fractional Fourier transform(FRFT)method to analyze the nonstationary vibration signal ofФ-OTDR.In the unified amplitude,time and frequency domain,the amplitude of nonstationary signal can be extracted more accurately than the conventional method.Based on analyzing the causes of the non-stationary signal ofФ-OTDR,the applicable conditions of FRFT are further discussed.The effectiveness of extracting the amplitude ofФ-OTDR signal by FRFT is validated by the actual third-party damage of urban electric pipe gallery.In the continuous amplitude,time and frequency domain analysis,the fractional Fourier transform can extract the amplitude information of non-stationary vibration signal more accurately,which is helpful to improve the accuracyФ-OTDR event detection and type analysis.

关 键 词：Ф-OTDR 分数阶傅里叶变换 非平稳信号 振动事件识别 

分 类 号：O439[机械工程—光学工程] TP212[理学—光学]