空中领航学(E_07)

AirNavigation空中领航学1北京航空航天大学飞行学院课件制作课程讲授王惠民AirNavigationAirNavigation空中领航学2Chapter7VORTheVOR(VHFomni-directionalradiorange)operatesintheradiofrequencyrange108–118MHZ,whichisintheveryhighfrequency(VHF)radioband.Thereare160individualchannels(frequencies)spacedat50kHzintervals.Asaback-uptovisualnavigation,wecanusetheVORfor:•orientation(whereamI?)byquicklyandeasilydeterminingapositionlinefromaVORgroundstation;and•trackingtoandfromaVOR.AirNavigation空中领航学3Asthenameomnisuggests,theVORradiatesaninfinitenumberoftracksinalldirections.EachradialisidentifiedbyitsmagneticbearingawayfromtheVORstation.AradialisamagneticbearingfromtheVOR.AirNavigation空中领航学4VORGroundSystemGroundStationTheVORgroundstationtransmitstwoVHFradiosignals:•thereferencephasesignal;and•thevariablephasesignal.AVORgroundstationAVORantennaVORGroundSystemAirNavigation空中领航学5TheantennaoftheVORairbornereceiverpicksupthetwosignals,thephasedifference(therelativedisplacementofthewavepeaks)ofwhichismeasured,thisdifferencedependinguponthemagneticbearingoftheaircraftfromthegroundstation.Inthismanner,theVORreceivercandeterminetheradialonwhichtheaircraftislocated.AirNavigation空中领航学6TheVORtransmitstwoVHFsignalswithaphasedifferencebetweenthem.ThetwosignalstransmittedbytheVORgroundstationvaryasfollowsinphase:•inphaseonmagneticnorth,whichisthereferencedirectionforallVORsignals;•90°outofphaseatmagneticeast090°M;•180°outofphaseatmagneticsouth180°M;•270°outofphaseatmagneticwest270°M;and•360°outofphaseatmagneticnorth360°Mor000°M.AirNavigation空中领航学7Every10secondsorsoaMorse-codeidentifiersignal(orident)istransmitted,modulatedat1,020Hz,allowingyoupositivelyidentifytheVOR.SomeVORsmayalsocarryvoicetransmissions.ThisallowstheVORtoprovideanautomaticterminalinformationservice(ATIS).AirNavigation空中领航学8GroundStationLikeallVHFtransmissions,therangeofVORsignalsisprimarilydeterminedbythelineofsightbetweenthetransmitterandthereceiver.TheprincipalfactorsthatgovernthemaximumrangeofaVOR(oranyVHF)transmitteraretherefore:•aircraftaltitude;•heightofthetransmittingantenna;and•heightofterrainbetweenthegroundstationandtheaircraft.AirNavigation空中领航学9Theseratedcoveragevaluesshouldbememorised.TheinformationcanbeusedtoassistyouintheplanningorselectionofthemostsuitableVORstationstouseinflight.ThepublishedratedcoveragefiguresforVHFnavaidsapplytobothdayandnight.AirNavigation空中领航学10VORpositions,frequenciesandMorse-codeidentsforVORstationsaregivenin:•EnRouteSupplementAustralia(ERSA);•enroutecharts(ERCs);•visualnavigationcharts(VNCs);and•visualterminalcharts(VTCs).WheretoFindDetailsofaVORAirNavigation空中领航学11InformationonVORstationsisavailableintheERSA.Theaerodromereferencepoint(ARP)is105°Mand1nmfromtheVOR.Position(Lat.&Long.)isS23°52.0´E151°12.3´IdentisGLAIdentisGLAFrequencyis116.3MHzAirNavigation空中领航学12VORdetailsonanERC-L.VORdetailsonaVTC.AirNavigation空中领航学13AirborneEquipmentTheVORairborneequipmentconsistsofthefollowingbasicitems:•Thetwin-blade,V-shapedantenna;•TheVORreceiver,anditsassociatedcontrolpanel;and•AVORindicatorisusedtointerpretthesignalsreceived.AirNavigation空中领航学14Omni-bearingIndicatorThesimplestandmostcommontypeofindicatoristheomni-bearingindicator(OBI).Acoursedeviationindicator(CDI)ontheOBIshowsdeviation,orangulardisplacement,oftheaircraftfromagiventrack(oromni-bearing)toorfromaVORgroundstation.Thetrackoromni-bearingissetbythepilotunderthecourseindexwiththeomni-bearingselector,orOBS.AirNavigation空中领航学15TheVORcockpitdisplayforaeroplanesonthe015radial.AirNavigation空中领航学16Thedegreeofangulardeviationfromtheselectedtrackismeasuredindots.Normallyastandardised5-dotdeviationscaleisused;thatis,5dotsarearrangedoneithersideofthecentre,witheachdotrepresenting2°ofangulardisplacementfromtheselectedtrack.Iftheaircraftisexactlyontheselectedtrack(oromni-bearing),theCDIneedlewillbecentred.A1-dotdeflectionoftheCDIrepresentsanangulardisplacementof2°;full-scaledeflectionrepresents10°ormore.AirNavigation空中领航学17TheTo/FromFlagTheto/fromflagorarrowsindicatewhethertheselectedomni-bearingwilltakeyoutotheVORgroundstationorawayfromit.AirNavigation空中领航学18Atalltimes,thereferencewhenusingtheVORindicatoristhetrackselectedusingtheOBScontrolandsetunderthecourseindex.Theselectedtrackdetermines:•CDIdeflection;and•theto/fromflagindication.AirNavigation空中领航学19TheVORDisplayIsNotHeadingSensitiveProvidedtheaircraftmaintainsthesamepositionrelativetotheselectedtrack,theCDIneedlewillnotmoveiftheaircraftchangesheading.AirNavigation空中领航学20OtherTypesofVORIndicatorRadioMagneticIndicatorA2-positionswitchisusuallyprovidedforeachneedleofRMI,allowingyoutoselecteitherADForVORnode,asdesired.AirNavigation空中领航学21IfVORisselected,theheadoftheRMIneedlewillindicatethemagneticbearingtotheVORstation,whilethetailoftheneedlewillindicatetheVORradialonwhichtheaircraftislocated,i.e.themagneticbearingfromthestation.AirNavigation空中领航学22HorizontalSituationIndicatorThetypicalhorizontalsituationindicator(HSI)isacombinationofaconventionalheadingindicator(HI)andtheVORCDI.TheHSIdisplaysaircraftheadingbelowanupperindexmark,orlubberline.Italsoincorporatesacoursebartoi