GlobalPositioningSystem（全球定位系統(tǒng)簡稱GPS）isanewgenerationofspacesatellitenavigationandpositioningsystemjointlydevelopedbytheU.S.armedforcesinthe1970s.Itsmainpurposeistoprovidereal-time,all-weatherandglobalnavigationserviceforthethreemajorareasofland,seaandair,andforintelligencegathering,nuclearexplosionmonitoringandemergencycommunicationsformilitarypurposes.ItisanimportantcomponentofthestrategyfortheUnitedStatestodominatetheglobal.Aftermorethan20yearsofresearchandexperimentsatacostof$30billion,24March1994,theGPSsatelliteconstellation,theglobalcoverageupto98%,hasbeenlaidtocomplete.IntroductionGPSHistoricalDevelopmentofGPS1978–LaunchoffirstGPSsatellite1985–KinematicGPSsurveying1989–LaunchoffirstBlockllsatelliteWideareadifferentialGPSconceptU.SCoastGuardGPSInformationSystem(GPSIC)1993–Real-timeKinematicGPSInitialoperationalcapability(IOC)onDecember8.1995–Fulloperationalcapability(FOC)onJuly171996–PresendentialDecisionDirective,firstU.SGPSpolicy2000–SelectiveavailabilitysettoZero.SatellitesorbitingtheEarthThetotalGPSconfigurationiscomprisedofthreedistinctsegments

(1)Thespacesegment-SatellitesorbitingtheEarth

(2)Thecontrolsegment-StationspositionedontheEarth’sequatortocontrolthesatellites.

(3)Theusersegment-AnybodythatreceivesandusestheGPSsignal.SystemOverviewBasicprinciplesofGPS

Positioningprinciple

Fourunknowsreceiver’sposition:（x,y,z）

receiver’s

clockdifference

Vt0

Intheory,weusethreesatellite’sinformationcanmakeoutthereceiver’location

Factly,useingthreesarellitecanonlymakesuretheLatitudeandlongitudeTransmissionmediaRadiowaves

suchasMicrowaveFeature:Widebandwidth

StableandReliableFlexibilityGooddirectionalLowcostPositioningsignalsTwoCarriersignalL1,L2Thefrequencyis1575.42MHzand

1227.60MHzTwoPseudo-randomcodeC/Acode1023bitPcodecodefrequency10.23MHzASignalcontainsthreedifferentbitsofinformation(1)Pseudorandomcode(2)Ephemerisdata(3)AlmanacdataTwoPositioningServiceSPSStandardPositioningServiceMainlyusingtheC/AcodeandprovideservicetothecivilianusersintheworldPPSPrecisionPositioningService

MainlysuingPcodeandprovideservicetotheofAmericaandit’sallylikeJapanFactorsaffectingaccuracyNumberofvisiblesatellitesPositiondilutionofprecisionSatelliteelevationsMultipathDistancebetweenspacestationandroverreceiversNumberofvisiblesatellitesPositiondilutionofprecisionSatelliteelevationsMultipathDistancebetweenspacestationandroverreceiversUsesofGPStechnologyLocation–DetermineabasicpositionNavigation–GettingfromonelocationtoanotherTracking–MonitoringthemovementofpeopleandthingsMapping–CreatingmapsTiming–Providingprecisetiming應用BeiDouBeiDou（COMPASS）NavigationSatelliteSystem(簡稱北斗)isnetworkof35satellitesdevelopedindependentlybyChina.Thesystem'spositioningandtimingdataareusedforavarietyofapplications,includingair,landandseanavigation,vehicleandvesseltracking,surveyingandmapping,assetandnaturalResourcemanagement.IntroductionHistoricalDevelopmentofBeiDou1980s–SettheplanofBeiDou2000-2004--Realizethefirststep2000-2012–FinishthesecondstepandRealizearegionalsource-off communication2012-2020–FinishthethirdstepandRealizeaglobalsource-off communication AboutsatelliteLineofdevelopmentSignalCharacteristicsThreecarriersignals’frequencybandB1:1559.052~1591.788MHzB2:1166.22~1217.37MHzB3:1250.618~1286.423MHzTillSatellitesurveySignal20125GEO+5IGSO+4MEO（Regionalservices）MainlythesignalofBeiDousystem’ssecondstage20205GEO+3IGSO+27MEO（Globalservices）MainlythesignalofBeiDousystem’sthirdstagesignalCenterfrequency(MHz)rate(cps)bandwidth(MHz)ModulationmodeServicemodeB1(I)1561.0982.0464.092QPSKopenB1(Q)2.046authorizedB2(I)1207.142.04624QPSKopenB2(Q)10.23authorizedB31268.5210.2324QPSKauthorizedThesignalofBeiDousystem’ssecondstagesignalCenter(MHz)Coderate(cps)Datarate(bps/sps)ModulationmodeServicemodeB1-CD1575.421.02350/100MBOC(6,1,1/11)OpenB1-CPNoB1-A2.04650/100BOC（14，2）authorizedNoB2aD1191.79510.2325/50AltBOC(15,10)openB2aPNoB2bD50/100B2bPNoB31268.5210.23500bpsQPSK(10)authorizedB3-AD2.557550/100BOC(15,2.5)authorizedB3-APNoThesignalofBeiDousystem’sthirdstageSystemcompositionThetotalBeiDouconfigurationiscomprisedofthreedistinctsegments

(1)Thespacesegment

(2)Thecontrolsegment

(3)TheusersegmentThespacesegmentGEO靜止軌道衛(wèi)星MEO衛(wèi)星中軌道衛(wèi)星Thespacesegmentismadeupof5GEOand30MEOsatellitesThecontrolsegmentThecontrolsegmentmainlymadeupofmasterstation,

uploadstationandmonitoringstations.

TheusersegmentTheusersegmentismainlymadeupofsomeBeiDou’sendsystemandsomeendsystembecompatiblewithotherGNCCBasicprinciplesofBeiDouBinarypositioning(雙星原理)Thatis,whenyougettwosatellites’positionandtheheight,throughmathematicalcomputationyoucangetthepoint’spositionyouwanttoknow.SystemServicesOpenService FacingwholeworldAuthorizationService Facingspecialusers通信communication水利waterconservancy減災disasterrelief海事marinefishery交通transportation氣象meteorological林業(yè)forestry

ApplicationCommunicationSuccessfullydevelopedthesystemwithBeiDou/GPSmode.What’smore,developedIntegratedsatelliteGPSclocksystem(研發(fā)了一體化衛(wèi)星授時系統(tǒng)).TD-SCDMA抗干擾螺旋天線北斗/GPS光纖拉遠授時示意圖Waterconservancyachievedreal-timetransmissionofhydrologicalforecastinformation（水文測報）inthemountainousregionsimprovedtheaccuracyoftheforecastsofdisasterdisasterrelief汶川地震救災現(xiàn)場減災中心工作人員在玉樹現(xiàn)場利用北斗用戶機報告災情Providingnationwidereal-timedisasterreliefcommandscheduling,emergencycommunicationsQuicklyreportingandsharingdisasterinformationEnhancingtherapidresponsecapabilityanddecision-makingabilityofdisasteremergencyrescue.Marinefishery基于北斗系統(tǒng)的海洋漁業(yè)綜合信息服務網(wǎng)絡海洋漁業(yè)應用分布

AchievingPositionMonitoring,emergencyrescue,informationdisseminationandmanagementoffishingboatsinandoutoftheharbortofisheriesmanagementdepartmentstransportationexcellentexamples:SatellitemonitoringsystemofpublictransportinXinjian“新疆公眾交通衛(wèi)星監(jiān)控系統(tǒng)”Roadinfrastructuresafetymonitoringsystem、“公路基礎設施安全監(jiān)控系統(tǒng)”Porthigh-precisionreal-timepositioningcontrolandsupervisionsystem“港口高精度實時定位調度監(jiān)控系統(tǒng)meteorologicaldevelopedaseriesofmeteorologicalforecastingCompassterminalequipment,raisedpracticalsystemapplicationsolutionssolvedtheproblemoftheautomatictransmissionandvisualizationofdigitalpacketsoftheNationalWeatherServiceandlocalmeteorologicalcenterweatherstations基于北斗的高原地區(qū)氣象監(jiān)測站

基于北斗的珠峰氣象監(jiān)測站forestry

forestfirepreventionsystemhasbeensuccessfullyusedincombat,isnowequippedwithmorethan700sets.項目

北斗衛(wèi)星導航系統(tǒng)GPS全球定位系統(tǒng)覆蓋范圍70°E一140°E,5°N一55°N

全球衛(wèi)星數(shù)量35

24衛(wèi)星軌道特性5顆同步和30顆非同步軌道衛(wèi)星21+3非同步軌道衛(wèi)星定位方式/原理有源/主動式雙向測距二維導航無源/被動式偽碼單向測距三維導航定位精度/m

幾十米6(P碼)，12(C/A碼)授時精度/ns100