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.