基于双谱边际谱的Φ-OTDR临近双振源定位方法  

Localization method ofΦ-OTDR near double sources based on bispectrum marginal spectrum

作　　者：施羿 王原野 赵雷[1] SHI Yi;WANG Yuanye;ZHAO Lei(Guangdong Provincial Key Laboratory of Digital Signal and Image Processing,Shantou University,Shantou Guangdong 515063,China)

机构地区：[1]汕头大学广东省数字信号与图像处理技术重点实验室,广东汕头515063

出　　处：《光通信技术》2020年第1期14-19,共6页Optical Communication Technology

基　　金：国家自然科学青年基金(61801283)资助;汕头大学科研启动基金(NTF18007)资助。

摘　　要：针对相位敏感型光时域反射仪(Φ-OTDR)系统无法分别定位间距小于其脉冲宽度的临近双振源的问题,通过分析临近双振源条件下Φ-OTDR信号的高次谐波特征及其在空间中的分布特性,提出一种基于双谱边际谱的定位方法。该方法在不改变硬件器件的情况下,可提高Φ-OTDR系统对临近双振源的分辨能力。实验测试表明:在200 ns脉冲宽度下(对应20 m空间分辨率),无论双振源以不同频率还是以相同频率振动,该方法均能分辨并分别定位相距5 m的2个振源。该研究工作将促进Φ-OTDR在管道安全监测以及结构健康监测中的应用。Aiming at the problem that the phase sensitiveΦ-optical time domain reflectometer(Φ-OTDR)system can't locate the two adjacent sources whose spacing is less than its pulse width,this paper analyzes the high-order harmonic characteristics ofΦ-OTDR signal and its spatial distribution characteristics under the condition of two adjacent sources,and proposes a location method based on the bispectrum marginal spectrum.This method can improve the locating ability ofΦ-OTDR without any additional hardware.The experiments show that this method can separately locate two vibration sources with 5 m interval under 200 ns probe pulse(means 20 m spatial resolution)and it can work no matter the same or different frequencies the two vibration sources are.This work will help the application ofΦ-OTDR system in pipeline safety monitoring and structural health monitoring.

关 键 词：相位敏感型光时域反射仪 双谱 高次谐波 空间分辨率 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]