Chang?E-5samples-New ?ground truth? for the quantitative inversion of lunar remote sensing br

The Chang'E-5(CE-5)missionsuccessfullyreturned1731 g of lunar soil samplesfrom the northeastof the OceanusProcellarum.The newly returnedlunar soil can providea new groundtruth for the quantitativeinversionof lunar remotesensingdata. In this study, the mineraland chemicalcompositions(FeO, TiO2, Th) of the landingregion were obtainedfrom the remotesensingdata and comparedwith the laboratoryanalysisresultsof the CE-5 lunar soil samples.Thedifferences betweenthem (especiallythe olivinecontent)indicatethat there is still room for improvementin the methodsfor retrievingthe elementaland mineralabundancesusing remotesensingdata. Througha systematiccomparativeanalysis,we discoveredthat: (1) the geochemicalcharacteristicsof high FeO, mediumTiO2, and abundantTh in the CE-5lunar soil are significantlydifferent from the existingApollolunar soil, which can provideuniquegroundtruth for remotesensingresearch;(2) The CE-5 lunar soil representsmaturelunar soil developedon the young basalt unit on the moon,with a small proportionof distantlysourcedejecta,representingthe mare basalt compositioncharacteristicsof thelandingregion;(3) The CE-5 lunar soil is very fine, which meets the samplestandard(<45 mu m) of the Lunar SoilCharacterizationConsortiumfor providinggroundtruth. Notably, the CE-5 landingregionalso exhibitsuniquecharacteristics:(1) it is locatedin the mid-latituderegion on the westernhemisphereof the moon, differentfrom the low-latituderegion where the UnitedStates and the Soviet Union samplereturn missionslanded;(2) it is locatedon the late-stage lunar basalt unit; it is differentfrom the existingspectralcalibrationarea. Therefore,the constructionof the CE-5landingarea as a new remotesensingcalibrationsite based on the measureddata of its lunar soil can significantlyexpandthe geographicalscope and global representationof the lunar calibrationsites. Based on the results of the remotesensingand samplestudies,we delineatethe calibrationarea in the unit where the CE-5 landingsite is located(Em4),thusprovidinga referencefor establishinga remote sensing calibration area in the future