DAS系统中微分交叉相乘与反正切解调算法研究

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中图分类号：TP212 文献标志码：A 文章编号：1002-4026（2025）06-0107-08

开放科学（资源服务）标志码（OSID）

Research on differential cross-multiplying and arctangent

demodulation algorithms in DAS systems

ZHANG Feng'，JIANG Yu1 ，SUI Xiang²，QIAO Xiaohan²，SHANG Ying²， ZHAO Wen'an²，LU Jingsheng²，WANG Chen² *

（1.China Olfield Services Limited，Sanhe 065201， China;2.Laser Research Institute，Qilu Universityof Technology （Shandong Academy of Sciences），Jinan ，China）

Abstract ： Distributed acoustic sensing（DAS） systems based on coherent optical time-domain reflectometry（COTDR） canobtainvibration informationalong thefiber lengthbydemodulating thephaseinformation fromthe backscattred Rayleigh signal inopticalfibers.Thephase demodulationalgorithmisa key technologyforphase extraction in DAS systems，and diferent algorithmsexert varying efects onthedemodulationresults.Thisstudyinvestigates the impactsof twoin-phasequadrature（IQ）demodulationalgorithms，i.e.，diferentialcross-multiplying（DCM）andarctangent （Arctan），onthedemodulation results.First，atheoretical analysis and numerical simulations basedon DCMandArctan are conducted.Subsequently，a COTDR-based DAS system is constructed to colect data，which are processd and analyzedusing both algorithms.Experimental results indicatethat the peak valuesof thedemodulated signals obtained usingthetwo algorithms difer by0.04rad，withanobserved phaseshiftof0.01rad.Inadition，basedonthediferent characteristics of the two algorithms，recommendations for their application scenarios are provided.

Keywords ：opticalfiber sensor；distributed opticalfiber sensing；distributed acoustic sensing；coherent optical time domain reflectometry；phase demodulation；vibration sensing

基于相干光时域反射计（coherent optical time-domain reflectometry，COTDR）的光纤分布式声波传感（distributed acoustic sensing，DAS）系统使用光纤作为传感器和信号传输媒介，集“传”与“感”于一体，不仅自身作为传输媒介天然完成组网，还可以测量传感光纤上任意位置的声波信息，实现全分布式的测量[1]。（剩余6248字）