使用雷达赤道大气对电离层进行1d 2d3d成像暑期murearimaging.pptx

1D,2D,and3Dimaging

ofatmosphereandionosphere

withtheMUradarandthe

EquatorialAtmosphereRadar(EAR)M.Yamamoto1andS.Fukao1,21:ResearchInstituteforSustainableHumanosphere(RISH),KyotoUniversity2:FukuiUniversityofTechnologyInternationalSymposium:FiftyYearsafterIGYNovember10-13,2008Tsukuba,Japan

CONTENTSMURadarImagingObservationSystem25-chdigitalreceiver(demodulator)+5-frequencyoperation

?Spatial-domainand/orFrequency-domainimagingiscapable.ImagingfromMUradarobservations.KHIandlayerstructuresintheloweratmosphere(1DFIIimaging).SpatialstructuresofFAIechoes(2Dspatial-domainimaging).3Dimagingintheloweratmosphere.Multi-beamImagingfromEquatorialAtmosphereRadar(EAR)observations.Temporalandspatialstructuresoftheequatorialspread-F(ESF).

SchematicdiagramoftheMUradar(afterupgrade)30%ofdegradedantennaradiatorandcableswererenewed.Polarizationswitchingrelayswereremoved.Fixedtoright-handedcircularpolarization.Digitalmodulatorandreceivers(demodulators)wereinstalled.FrequencyandpulsetimingsaresynchronizedtoGPStime/frequencystandard.

DigitalreceiverAnalogfilterIFsignal(5MHz)AnalogLOsignal(cosinesine)A/Dconv.(1MHz)A/Dconv.(1MHz)RangesamplingRangesamplingIcomponentQcomponentAnalogreceiverAnalogsignalDigitalsignalDigitalreceiverFiltercharacteristics(especiallyphase)arenoteasytocontrol.DCoffsetremainsinIQsignal.(=largerclutter)RemainingIQimbalancecausesghostinDopplerspectrum.NoDCoffsetNoIQimbalanceEasytokeepsamespec.betweenchannelsA/Dconv.(20MHz)IFsignal(5MHz)DigitalfilterDigitalfilterDecima-tionDecima-tionDigitalLOsignalcosine:0,+1,0,-1,0,sine:-1,0,+1,0,1IcomponentQcomponentRangesampling(1MHz)Rangesampling(1MHz)

MUradarbeamforming/steeringElectroniccontrolofphasedifferencebetweenYagiantennasformsandsteersthebeamofthewholearray-antenna.Workassameasgigan