简介：ElectrondensityisakeyparametertocharacterizeMartianionosphericstructureanddynamics.BasedontheephemerisandauxiliaryinformationderivedfromtheSpacecraft,Planet,Instruments,C-matrix,andEvents(SPICE)toolkit,wecalculatedthebendingangleofsignalpathfromthefrequencyresidualsmeasuredbytheMarsExpressRadioScienceExperiment(MaRS)oftheMarsExpress(MEX)missionundertheassumptionofasphericallysymmetricionosphere.Westratifiedtheionosphereintolayersandassumedalinearchangeofbendinganglebetweenlayers,toderiveprofilesinradialdistanceofrefractivitywiththeoptimizedparametersofupperintegrallimitof4890kmandbaselinecorrectionboundaryof3690km.Meanwhile,wealsocomparedtheretrievedelectrondensityprofilesbetweenthefrequencyresidualsofthesingle-frequencyanddifferentialDopplerofthedual-frequency.Intotal,~640electrondensityprofilesofMartianionospherebetweenApril2004andApril2015wereretrievedsuccessfully.Thereare24profilesidentifiedmanuallythatexhibitanadditionalsporadiclayeroccurrencebelowthenormaltwo-layers.Wealsofoundthatthepeakaltitudeofthislayerincreaseswiththemainpeakaltitude.

简介：Inrecentyears,radiooccultation(RO)technologymakinguseofglobalpositioningsystem(GPS)signalshasbeenexploitedtoobtainprofilesofatmosphericparametersintheneutralatmosphere.Inthispaper,theROrefractivityprofilesobtainedfromtheConstellationObservingSystemforMeteorology,IonosphereandClimate(COSMIC)missionarestatisticallycomparedwiththeobservationsof38radiosondestationsprovidedbytheAustralianBureauofMeteorologyduringtheperiodfrom15July2006through15July2007.Di?erentcollocationcriteriaarecomparedatfirst,andCOSMICROsoundingsthatoccurwithin3hoursand300kmofradiosondemeasurementsareusedforthefinalstatisticalcomparison.TheoverallresultsshowthattheagreementsbetweentheCOSMICrefractivityprofilesandtheradiosondesoundingsfromthe38stationsareverygoodat0–30kmaltitude,withmeanabsoluterelativerefractivitydeviationsoflessthan0.5%.Latitudinalcomparisonsindicatethattherearenegativerefractivitydeviationsinthelowertroposphereoverthelowlatitudeandmiddlelatituderegionsandlargestandarddeviationsexistinthelowertroposphereoflowlatituderegions,whichcanreachupto～6%.ThecomparisonsofCOSMICROrefractivityprofilesandradiosondeobservationsfor3polarstationsinfourdifferentseasonsindicatethattheaccuracyofGPSROprofilesisbetterintheAustralsummerandautumnthanintheAustralspringandwinterduringtheyearfromSeptember2006toAugust2007.

简介：ＴＥＭＰＥＲＡＴＵＲＥ－ＭＥＡＳＵＲＩＮＧＲＡＤＩＯ－ＡＣＯＵＳＴＩＣＳＯＵＮＤＩＮＧＳＹＳＴＥＭ（ＲＡＳＳ）￥ＬｉＪｉａｎｇｕｏ（李建国），ＷａｎｇＰｉｎｇ（王坪）ａｎｄＭｅｎｇＺｈａｏｌｉｎ（孟昭林）ＴＥＭＰＥＲＡＴＵＲＥ－ＭＥＡＳＵＲＩＮＧＲＡ...

简介：Radio-frequencyinterference(RFI)affectsgreatlythequalityofthedataandretrievalproductsfromspace-bornemicrowaveradiometry.AnalysisoftheAdvancedMicrowaveScanningRadiometerontheEarthObservingSystem(AMSR-E)AquasatelliteobservationsrevealsverystrongandwidespreadRFIcontam-inationsontheC-andX-banddata.Fortunately,thestrongandmoderateRFIsignalscanbeeasilyidentifiedusinganindexonobservedbrightnesstemperaturespectrum.ItistheweakRFIthatisdiffi-culttobeseparatedfromthenaturesurfaceemission.Inthisstudy,anewalgorithmisproposedforRFIdetectionandcorrection.Thesimulatedbrightnesstemperatureisusedasabackgroundsignal(B)andadepartureoftheobservationfromthebackground(O-B)isutilizedfordetectionofRFI.ItisfoundthattheO-Bdeparturecanresultfromeitheranaturalevent(e.g.,precipitationorflooding)oranRFIsignal.AseparationbetweenthenatureeventandRFIisfurtherrealizedbasedonthescatteringindex(SI).ApositiveSIindexandlowbrightnesstemperaturesathighfrequenciesindicateprecipitation.IntheRFIcorrection,arelationshipbetweenAMSR-Emeasurementsat10.65GHzandthoseat18.7or6.925GHzisfirstdevelopedusingtheAMSR-EtrainingdatasetsunderRFI-freeconditions.ContaminationofAMSR-Emeasurementsat10.65GHzisthenpredictedfromtheRFI-freemeasurementsat18.7or6.925GHzusingthisrelationship.ItisshownthatAMSR-EmeasurementswiththeRFI-correctionalgorithmhavebetteragreementwithsimulationsinavarietyofsurfaceconditions.

简介：ThecharacteristicsoftheatmosphericboundarylayerheightovertheglobaloceanwerestudiedbasedontheConstellationObservationSystemofMeteorology,IonosphereandClimate(COSMIC)refractivitydatafrom2007to2012.Resultsshowthattheheightismuchcharacteristicofseasonal,inter-annualandregionalvariation.Globally,thespatialdistributionoftheannualmeantopheightshowsasymmetricalzonalstructure,whichismorezonalintheSouthernHemispherethanintheNorthernHemisphere.Theboundarylayertopishighestinthetropicsandgraduallydecreasestowardshigherlatitudes.Theheightisinarangeof3to3.5kminthetropics,2to2.5kminthesubtropicalregions,and1to1.5kmorevenlowerinmiddleandhighlatitudes.Thediurnalvariationofthetopheightisnotobvious,withtheheightvaryingfromtenstohundredsofmeters.Furthermore,itisdifferentfromregiontoregion,someregionshavethemaximumheightduring9:00to12:00,othersat15:00to18:00.

简介：

简介：