Definition
Satellitesorartificialsatellitesorbitingtheearthinthisorbitarealwayslocatedatthesamepositiononthesurfaceoftheearth.Itsorbitaleccentricityandorbitalinclinationarebothzero.Themovementperiodis23hours,56minutesand04seconds,whichcoincideswiththerotationperiodoftheearth,andtheorbitalradiusis42164.169km.Sincethetrajectoryofthesub-satellitepointofasatellitemovinginageostationaryorbitisapoint,observersonthegroundcanalwaysobservethesatelliteatthesamepositionintheskyatanyhourandwillfindthatthesatelliteisstationaryinthesky,somanyman-madeSatellites,especiallycommunicationsatellites,mostlyusegeostationaryorbits.Geostationaryorbitservicetechnologyisofgreatsignificanceinpromotingthedevelopmentofeconomy,nationaldefenseandspacetechnology.
ThetheoryofgeostationaryorbitwasfirstproposedbyHermanPotosnikin1928,andthenArthurCharlesClarkeproposedtoplacecommunicationsatellitesinhisnovel"WirelessWorld"Ingeostationaryorbit.Therefore,sometimesthestationaryorbitisalsocalledtheClarkeorbit.Thesatellitelocatedinthisorbit(referredtoasGEOsatellite)hasalargecoveragearea(asatellitecancoveralmosttheentirehemisphere)andisstationaryrelativetotheground.Therefore,itisplayingaroleincivilandmilitaryfieldssuchascommunications,navigation,earlywarning,andmeteorology.Anincreasinglyimportantrole.
Description
Theartificialsatelliteisrelativelystationarywiththegroundandfixedabovetheequator.Inadirectcircularorbit,thealtitudeis35,786kilometersfromtheground,andthespeedofthesatelliteis3.07kilometerspersecond.Asatellitecancoverabout40%oftheearth'sarea.Meteorologicalsatellites,communicationsatellites,andbroadcastingsatellitesoftenusethisorbit.Inaddition,somesatellitesofmycountry'sBeidousatellitenavigationsystemalsousethisorbit.
Differences
Actually,geosynchronousorbitandgeostationaryorbitarenotthesamething.Theyhavesimilaritiesanddifferences.
Thegeosynchronousorbitandthegeostationaryorbitarebothman-madeearthsatelliteorbitswiththesameoperatingperiod(23hours,56minutesand04seconds).
Therearethreedifferencesbetweenthesetwokindsoforbits:
First,thereisadifferenceinorbitalinclination.
Thegeostationaryorbitisacirculargeosynchronousorbitwithanorbitalinclination(theanglebetweentheorbitalplaneandtheequatorialplane)ofzero.Thatis,thegeostationaryorbitmustbeontheequatorialplane;andthegeosynchronousorbitplanecanformanon-zeroanglewiththeequatorialplane.
Secondly,thephenomenonthattheobserverseesisdifferent.
Satellitesoperatingingeosynchronousorbitpassthroughtheskyinthesameplaceatthesametimeeveryday.Forobserversontheground,thesatellitesappearinthesamedirectionatthesametimeeveryday.Inacontinuousperiodoftime,thesatellitecanmoverelativetotheobserver.Satellitesoperatinginthegeostationaryorbitarealwaysabovethesameplaceatanytimeoftheday.Observersonthegroundseethatthesatellitesarealwaysinacertainpositionandremainstationary.
Third,thetrajectoriesofthesub-satellitepointsaredifferent.
Theprojectionpointoftheartificialearthsatelliteontheground(ortheintersectionpointbetweenthesatelliteandthecenteroftheearthandtheground)iscalledthesub-satellitepoint.Themotionofthesatelliteandtherotationoftheearthcausethesub-satellitepointtomoveontheearth,formingthetrajectoryofthesub-satellitepoint.Thesub-satellitetrajectoryofageostationarysatelliteisafigure-eightclosedcurve,whilethesub-satellitetrajectoryofageostationarysatelliteisapoint.
Environment
geosynchronousorbitenvironmentgeosynchronousorbitenvironmentThespaceenvironmentofthegeostationaryorbitarea.Thegeostationaryorbitisahigh-densityareaofcommunicationsatellites,whichislocatedinthenear-equatorareaabout6.6earthradiifromthecenteroftheearth.Thespaceenvironmentinthisareaismainlycomposedofhigh-energyparticles,thermalplasma,plasmalayerplasma,ringcurrent,magneticfield,solarelectromagneticradiation,meteoroidsandspacedebrisexceptgravitationalfield.Thegeostationaryorbitzoneisanareawheretheearth'sspaceenvironmentisseriouslyaffectedbysolaractivities.Whenthestrongsolarwindarrives,themagnetosphereiscompressed,andthegeostationaryorbitzoneiscompletelyexposedtothesolarcosmicraysandhigh-speedsolarwind.Duringamagneticstormorsubstorm,thehigh-temperatureplasmainjectedfromthemagnetictailcanalsoreachthisarea,makingthisareaahigh-pronespaceenvironmentthattriggersspacecraftanomalies,wherehigh-energyparticles(includingsolarprotonevents)environmentandsubstorminjectionThethermalplasmaenvironmentisthemostimportantenvironmentthatcausesanomaliesandistheareawherethespacecraftchargingproblemisthemostserious.
Related
SpaceStation-CommunicationSatellite
Acommunicationsatelliteisasatelliteusedasaradiocommunicationrelaystation.Itislikeaninternationalmessenger,collectingallkindsof"letters"fromtheground,andthen"delivering"themtousersinanotherplace.Sinceitisa"station"atanaltitudeof36,000kilometers,its"delivery"coverageisparticularlylarge,andasinglesatellitecanberesponsibleforcommunicationon1/3oftheearth'ssurface.Ifthreecommunicationsatellitesareevenlyplacedonthegeostationaryorbit,globalcommunicationscanbeachievedinadditiontothenorthandsouthpoles.Whenasatellitereceivesaweakradiosignalfromagroundstation,itwillautomaticallyturnitintoahigh-powersignal,andthensendittoanothergroundstation,ortoanothercommunicationsatellite,andthensendittotheearth.Ononesideofthegroundstation,inthisway,wereceivedsignalssentfromfaraway.
Communicationsatellitesgenerallyuseageostationaryorbit,whichislocated35,786kilometersabovetheearth'sequator.Onthisorbit,thesatelliterevolvesaroundtheearthfromwesttoeastataspeedof3,075meterspersecond,andthetimetoorbittheearthis23hours,56minutesand4seconds,whichisexactlythesameasthetimefortheearthtorotateonce.Therefore,fromtheground,thesatelliteimagehangsintheskyanddoesnotmove,whichmakestheworkofthegroundreceivingstationmuchmoreconvenient.Theantennaofthereceivingstationcanbefixedlyalignedwiththesatellite,anditcancommunicatedayandnightwithoutinterruption.Thereisnoneedto"shake"aroundliketrackingthosemovingsatellites,sothatthecommunicationtimeisintermittent.Communicationsatelliteshaveundertakenallintercontinentalcommunicationservicesandtelevisiontransmissions.
Communicationsatellitesareoneoftheearliestandmostwidelyusedsatellitesintheworld.Manycountrieshavelaunchedcommunicationsatellites.OnApril6,1965,theUnitedStatessuccessfullylaunchedtheworld'sfirstpracticalgeostationaryorbitcommunicationsatellite:Int'lCommunicationSatellite1.Sofar,thistypeofsatellitehasdevelopedtotheeighthgeneration,andeachgenerationhasimprovedintermsofvolume,weight,technology,communicationcapabilities,andsatellitelife.
ThecommunicationssatellitesoftheformerSovietUnionwerenamed"Bliksem",includingBliksem1,2,3,etc.DuetothevastterritoryoftheformerSovietUnion,mostoftheBliksemsatellitesarenotinageostationaryorbit,butinanellipticalorbitwithalargeeccentricity.
China’sfirstgeostationaryorbitcommunicationsatellitewaslaunchedonApril8,1984,named"DongfanghongII",andsixsatelliteshavebeensuccessfullylaunchedsofar.Thesesatelliteshavesuccessivelyundertakenbroadcasting,televisionsignaltransmission,andlong-distancecommunications,andhaveplayedahugeroleintheconstructionofthenationaleconomy.