学科分类
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1 个结果
  • 简介:MeteoroidsenteringtheEarth'satmospherecancreatemeteortrailirregularityseriouslydisturbingthebackgroundionosphere.AlthoughnumerousobservationsofmeteortrailirregularitieswereperformedwithVHF/UHFcoherentscatterradarsinthepast,nosimultaneousradarandopticalinstrumentswereemployedtoinvestigatethecharacteristicsofmeteortrailirregularityanditscorrespondingmeteoroid.ByinstallingmultiplevideocamerasneartheSanyaVHFradarsite,anobservationalcampaignwasconductedduringtheperiodfromNovember2016toFebruary2017.Atotalof242opticalmeteorswithsimultaneousnon-specularechoesbackscatteredfromtheplasmairregularitiesgeneratedinthecorrespondingmeteortrailswereidentified.Agoodagreementbetweentheangularpositionsofnon-specularechoesderivedfromtheSanyaradarinterferometerandthoseofopticalmeteorswasfound,validatingthattheradarsystemphaseoffsetshavebeenproperlycalibrated.TheresultsalsoverifytheinterferometrycapabilityofSanyaradarformeteortrailirregularityobservation.Thenon-specularechoeswithsimultaneousopticalmeteorsweredetectedatmagneticaspectanglesgreaterthan~78°.Basedonthemeteorvisualmagnitudeestimatedfromtheopticaldata,itwasfoundthattheradarnonspecularechoescorrespondingtobrightermeteorssurvivedforlongerduration.Thiscouldprovideobservationalevidenceforthesignificanceofmeteoroidmassonthedurationofmeteortrailirregularity.Ontheotherhand,thesimultaneousradarandvideocommon-volumeobservationsshowedthatthereweresomecaseswithopticalmeteorsbutwithoutradarnon-specularechoes.Onepossibilitycouldbethatsomeoftheopticalmeteorsappearedatextremelylowaltitudeswheremeteortrailirregularitiesrarelyoccur.

  • 标签: METEOR IONOSPHERE RADAR non-specular echo