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ID:53762283
大小:1.11 MB
页数:9页
时间:2020-04-24
《基于广义谐波小波变换的布里渊光时域反射计的数字包络解调技术-论文.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第33卷第5期光学学报Vol_33,NO.52013年5月ACTA0PTICASINICAMay.2013基于广义谐波小波变换的布里渊光时域反射计的数字包络解调技术杨巍杨远洪(JK京航空航天大学仪器科学与光电工程学院光电工程系,北京100191)摘要分析了相干探测型布里渊光时域反射计(BOTDR)的信号特征及信号包络对其空间分辨率和布里渊频移测量精度等参数的影响,总结了幅度调制信号的数字包络解调算法模型和理想的数字包络解调算法的特性。根据广义谐波小波(GHW)的零相移理想带通滤波特性及通带参数可灵活设计的特点,提出了一种基于广义谐波小波变换(GHWT)的BOTDR的数字包络解调技术,设计了解
2、调方案并进行了参数优化和实验研究。结果表明,与现有BOTDR数字包络解调技术相比,所提出的新技术能够无失真地提取BOTDR的信号包络并具有较强的噪声抑制能力,从而在不影响BOTDR的空间分辨率的情况下提高布里渊频移测量精度。最后,还根据解调算法的频域特性对实验结果进行了分析。关键词传感器;光纤传感;布里渊光时域反射计;广义谐波小波变换;包络解调中图分类号TN247文献标识码Adoi:10.3788/AOS201333.0506004DigitalEnvelopeDetectionTechniqueforBrillouinOpticalTime.DomainReflectometryBased
3、onGeneralizedHarmonicWaveletTransformYangWeiYangYuanhong(DepartmentofOpto—ElectronicsEngineering,SchoolofInstrumentationScienceandOpto—ElectronicsEngineering,BeihangUniversity,Bering100191,China)AbstractThesignalcharacteristicsofthecoherentheterodyneBrillouinopticaltime—domainreflectometry(BOTDR),a
4、swellastheimpactsofthesignalenvelopeonthespatialresolutionandBrillouinfrequencyshift(BFS)measurementaccuracyoftheBOTDRareanalyzed,respectively.Ageneralalgorithmmodelforthedigitalenvelopedetectionofanamplitude—modulated(AM)signalandthefeaturesofanidealdigitalenvelopedetectionalgorithmaresummarized,r
5、espectively.Accordingtothezerophaseshiftidealbandpassfilteringfeaturesandpassbanddesigningflexibilityofthegeneralizedharmonicwavelet(GHW),adigitalBOTDRenvelopedetectiontechniquebasedonthegeneralizedharmonicwavelettransform(GHWT)isproposed,andtheenvelopedemodulationschemeisdesigned.Theparametersopti
6、mizationandexperimentsaremade.Theresultsshowthat,comparedwiththeexistingtechniques·anundistortedsignalenvelopewithahighersignal—to-noiseratiocanbeobtainedbytheproposedmethod,resultinginanundegradedspatialresolutionandahigherBFSmeasurementaccuracyfortheBOTDRsystem.Theexperimentalresultsarealsoanalyz
7、edaccordingtothefrequencydomaincharacteristicsofthealgorithms.Keywordssensor;fiberopticsensing;Brillouinopticaltime—domainreflectometry;generalizedharmonicwavelettransform;envelopedetectionoCIScodes060.2370
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