简介：Todetectthelaserdopplersignal,theunknownsignalistrackedbytheknownsignalusingtheconceptoftopologicalcontravariance.TheunknowntopologicalspaceUandknownspaceMarefounded,andthentheunknownsignal'stransformationistrackeddynamicallyaccordingtothismappingrelationshipbetweenthetwospaces.Thesystemequationisobtainedbygradient-descentmethod,andtheconditionsofstabilityaregivenbyPoincarémapping.Theproposedmethodisappliedtomeasurethein-planedisplacementsignalofthesolid50mawayusinglaserdoppler,signal.Theresultprovesthatthemethodcandetectlaserdoppler.signalaccurately,itsrelativeerrorislessthan0.7%.

简介：目标结构的机械颤动将调制雷达backscattering的阶段函数，并且将从目标导致返回的信号的频率调整。它产生目标身体Doppler频率的乐队转移的一个方面，它对目标识别有用。基于这，micro-Doppler原子宝库为目标识别被造，并且四种普通分类器独立被使用执行分类识别。模拟试验性的结果证明这个方法让高识别超过90%评价。

简介：AjammingsuppressionmethodbasedonpolarizationsignaldetectionisproposedundercommonrangeandvelocitycheatingjammingforpulseDopplerradar.Onthebasisoftheseparationofthetargetandthejamming,therangeandvelocitytrackonthetruetargetarerealized.FirstlythesignalprocessingmodelofthefullpolarizationpulseDopplerradarisintroduced.Secondlythemethodofcorrecttargetseparationisdiscussed,whichisthetwicedetectionsofenergyandpolarizationstateonthetwodimensionresolutioncellsofrangeandvelocityoftheradarecho.Finallythesimulationsareperformedandtheresultsprovethevalidity.What'smore,multiplerangeandvelocitycheatingjammingcanbesuppressedatthesametimeifthetargetandthejammingaredifferentinthepolarizationdomain.

简介：Range-Doppler(RD)methodandReverse-Range-Doppler(RRD)methodarecombinedtogethertoachieveautomaticgeocodingofSyntheticApertureRadar(SAR)imagequicklyandaccuratelyinthepaper.TheRDmethodisfirstlyusedtolocatethefourcornersoftheimage,thentheotherpixelsoftheimagecanbelocatedbyReverse-Range-Doppler(RRD)method.Resamplingisperformedatlast.Theapproachhasanadvantageoverprevioustechniquesinthatitdoesnotrequiregroundcontrolpointsandisindependentofspacecraftattitudeknowledgeorcontrol.ItcancompensatetheshiftduetotheassumedDopplerfrequencyinSARimagepreprocessing.RRDsimplifiestheprocessofRD,thereforespeedsupthecomputation.TheexperimentalresultsshowthataSARimagecanbeautomatedgeocodedin30susingthesingleCPU(3GHz)with1Gmemoryandanaccuracyof10misattainablewiththismethod.

简介：Inanactiveradar-trackingsystem,thetarget-motionmodelisusuallymodeledintheCartesiancoordinates,whiletheradarmeasurementusuallyisobtainedinpolar/sphericalcoordinates.Thereforethetarget-trackingproblemintheCartesiancoordinatesbecomesanonlinearstateestimationproblem.Anumberofmeasurement-conversiontechniques,whicharebasedonpositionmeasurements,arewidelyusedsuchthattheKalmanfiltercanbeusedintheCartesiancoordinates.However,theyhavefundamentallimitationstoresultinfilteringperformancedegradation.Infact,inadditiontopositionmeasurements,theDopplermeasurementorrangerate,containinginformationoftargetvelocity,hasthepotentialcapabilitytoimprovethetrackingperformance.AfilterisproposedthatcanuseconvertedDopplermeasurements(i.e.theproductoftherangemeasurementsandDopplermeasurements)intheCartesiancoordinates.ThenovelfilteristheoreticallyoptimalintheruleofthebestlinearunbiasedestimationamongalllinearunbiasedfiltersintheCartesiancoordinates,andisfreeofthefundamentallimitationsofthemeasurement-conversionapproach.Basedonsimulationexperiments,anapproximate,recursiveimplementationofthenovelfilteriscomparedwiththoseobtainedbyfourstate-of-the-artconversiontechniquesrecently.Simulationresultsdemonstratetheeffectivenessoftheproposedfilter.

简介：Vehicularnodepositioningneedstobequickandpreciseonhighwayforsafetyconsidera-tion.Inthispaper,wepresentanovelandpracticalvehicularnodepositioningmethodwhichcanachieveahigheraccuracyandmorereliabilitythantheexistingglobal-positioning-system-basedpo-sitioningsolutionsbymakinguseofDoppler-shiftedfrequencymeasurementstakenbyvehicularnodeitself.Thispositioningmethodusesinfrastructurenodeswhichareplacedontheroadsideeveryseveralkilometersasradiationsourcestoestimatetherelativedistancesofvehicletotheinfrastructurenode.Throughcoordinateconversion,wegettheabsolutecoordinatesofvehicularnodebasedonknownabsolutecoordinatesofinfrastructurenode.Wealsoanalyzetheoptimaldistanceofneighborinfra-structurenodesinordertoensureahighaccuracy.Inaddition,simulationresultsdemonstratethattheaccuracyofourmethodwithExtendedKalmanFiltering(EKF)issuperiortothemethodwithoutEKF.

简介：Ubiquitousradarisanewradarsystemthatprovidescontinuousanduninterruptedmultifunctioncapabilitywithinacoveragevolume.Continuouscoveragefromclose-in'pop-up'targetsincluttertolong-rangetargetsimpactsselectionofwaveformparameters.Thecoherentprocessinginterval(CPI)mustbelongenoughtoachieveacertainsignal-to-noiseratio(SNR)thatensurestheefficiencyofdetection.TheconditionofdetectioninthecaseoflowSNRisanalyzed,andthreedifferentcasesthatwouldoccurduringintegrationarediscussedandamethodtodeterminetheCPIispresented.ThesimulationresultsshowthattargetsdetectionwithSNRaslowas-26dBintheexperimentalsystemcanpossiblydeterminetheCPI.

简介：Themobilechannelisslowfadingandtimeselective,thusthemultiplicativeandadditivenoiseofthechannelwillsmearthespectralline,orarouseDopplerspread.Thisspreadwillmaketheparametersestimationaccuracydegrade.ThegoalofthispaperistoanalyticallyassessthisdegradationwhenCarrierFrequencyOffset(CFO)andDopplershiftexistjointly.Thenthefinite-sampleCramer-RaoLowerBound(CRLB)isderivedandclose-formasymptoticalexpressionisgivenforlarge-sampleCRLB.Theseexpressionsgiveinsightsintotheperformanceroomforfrequencyestimation.AlsothevarianceofDopplershiftestimatorissimulatedtoillustratethetheoreticalresults.

简介：Anovelrotationalinvariancetechniqueforblindestimatesofdirectionofarrival(I)OA)andDopplerfrequencywithunknownarraymanifoldduetoarraysensoruncertaintiesisproposed,takingDopplerfrequencydifferencebetweenasuccessivepulsesasrotationalparameter.Theeffectivenessofthenewmethodisconfirmedbycomputersimulation.Comparedwiththeexisting2-DDOA-frequeucyestimatetechniques,thecomputationloadoftheproposedmethodcanbesavedgreatly.