《智能传感器装调与测试（双语）》课件-12.GPS定位认知

卫星导航定位原理（GNSS定位）PrincipleofSatelliteNavigationandPositioning(GNSSPositioning)国内大部分汽车已经拥有卫星定位导航等基础功能，达到了网联辅助信息交互级别。Mostdomesticcarsalreadyhavebasicfunctionssuchassatellitepositioningandnavigation,reachingthelevelofnetworkedauxiliaryinformationinteraction.PART01卫星导航定位原理（GNSS定位）PrincipleofSatelliteNavigationandPositioning(GNSSPositioning)卫星导航定位原理（GNSS定位）PrincipleofSatelliteNavigationandPositioning(GNSSPositioning)根据几何学理论证明，通过精确测量地球上某个点到三颗卫星之间的距离，能对此点的位置进行三角形测定，这就是GNSS定位的基础原理。Accordingtogeometrictheory,byaccuratelymeasuringthedistancebetweenapointontheearthandthreesatellites,thepositionofthispointcanbetriangulated.ThisisthebasicprincipleofGNSSpositioning.卫星导航定位原理（GNSS定位）PrincipleofSatelliteNavigationandPositioning(GNSSPositioning)接收机不具备十分准确的时钟，且与卫星时钟不同步，因此需要考虑钟差，来修正误差Thereceiverdoesnothaveaveryaccurateclockandisnotsynchronizedwiththesatelliteclock,soitisnecessarytoconsidertheclockerrortocorrecttheerror通过4个卫星参数，得出四个未知参数

Through4satelliteparameters,fourunknownparametersareobtained——纬度（B）

-Latitude(B)

——经度（L）

-Longitude(L)

——高程（h）

-Elevation(h)

——钟差（T）

-Clockerror(T)

卫星导航定位原理（GNSS定位）PrincipleofSatelliteNavigationandPositioning(GNSSPositioning)主要是因为接收机与卫星采用的不同时钟，卫星上采用色原子钟，接收机的时钟为普通的时英钟。接收机不具备十分准确的时钟与卫星时钟不同步。在电磁波传播速率为3×10的8次方的情况下，微小的时间误差将会使得距离信息出现巨大的失真。Thisismainlybecausethereceiverandsatelliteusedifferentclocks.Thesatelliteusesacoloratomicclock,whilethereceiver'sclockisanordinaryhourclock.Thereceiverisnotsynchronizedwiththesatelliteclock,lackingahighlyaccurateclock.Undertheelectromagneticwavepropagationspeedof3×108m/s,evenasmalltimingerrorcancausesignificantdistortioninthedistancemeasurements.PART02卫星导航定位误差SatelliteNavigationandPositioningError卫星导航定位误差SatelliteNavigationandPositioningError卫星误差

Satelliteerror大气误差

Atmosphericerror多路径误差

Multipatherror设备误差

Equipmenterror误差来源

Sourceoferror误差范围/m

Errorrange/m信号传播误差

Signalpropagationerror电离层延迟误差

Lonosphericdelayerror1.5~15对流层延迟误差

Troposphericdelayerror多径效应误差

Multipatheffecterror卫星误差

Satelliteerror卫星星历误差

Satelliteephemeriserror1.5~15卫星时钟误差

Satelliteclockerror相对论效应

Relativisticeffect设备误差

Equipmenterror接收机时钟误差

Receiverclockerror1.5~5位置误差

Positionerror天线相对中心位置的偏差

Deviationoftheantennarelativetothecenterposition地球转动误差

Earthrotationerror地球潮汐

Earthtides1地球自转的影响

Effectsoftheearth'srotation影响最大的就是信号传播误差

ThebiggestimpactisthesignalpropagationerrorPART03差分定位原理PrincipleofDifferentialPositioning差分定位原理PrincipleofDifferentialPositioning位置差分:将坐标测量值与基准站真实坐标值的差值作为差分矫正量Positiondifference:Thedifferencebetweenthecoordinatemeasurementvalueandtherealcoordinatevalueofthebasestationisusedasthedifferentialcorrectionamount真实坐标值

Realcoordinatevalue坐标测量值

Coordinatemeasurementvalue数据链路

Datalink基准站

Basestation移动站

Mobilestation将一台卫星信号接收机安置在基准站上，根据基准站已知精密坐标，计算出基准站到卫星的距离改正数，并由基准站实时将改正数据发送出去。移动站在进行卫星观测数据时，也接收到基准站发出的改正数，并对其定位结果进行改正，从而提高定位精度。Asatellitesignalreceiverisplacedonthebasestation.Accordingtotheknownprecisecoordinatesofthebasestation,thedistancecorrectionnumberfromthebasestationtothesatelliteiscalculated,andthebasestationsendsthecorrectiondatainrealtime.Whenthemobilestationperformssatelliteobservationdata,italsoreceivesthecorrectionnumbersentbythebasestationandcorrectsitspositioningresult,therebyimprovingthepositioningaccuracy.差分定位原理PrincipleofDifferentialPositioning载波相位差分（RTK）:实时处理两个观测站载波相位观测量。Carrierphasedifferential(RTK):Real-timeprocessingofcarrierphaseobservationsfromtwoobservationstations.伪距差分:将基准站到卫星的测量伪距和实际卫星位置与基准站真实位置所求的真实几何距离之间的伪距修正值作为差分矫正量Pseudo-rangedifferential:Thepseudorangecorrectionvaluebetweenthemeasuredpseudorangefromthebasestationtothesatelliteandtherealgeometricdistanceobtainedbytheactualsatellitepositionandtherealpositionofthebasestationisusedasthedifferentialcorrectionamount真实距离S

TruedistanceS伪距S1

PseudorangeS11、修正法：基准站将载波相位的修正值发给移动站1.Correctionmethod:Thebasestationsendsthecorrectionvalueofthecarrierphasetothemobilestation.

2、求差法：基准站将载波相位发给移动站，由移动站将观测值求差进行坐标解算2.Differencemethod:Thebasestationsendsthecarrierphasetothemobilestation,whichcalculatesthedifferencebetweentheobserved