空中领航学(E-02)

AirNavigation空中领航学1飞行学院AirNavigation课件制作课程讲授王惠民AirNavigation空中领航学2飞行学院Chapter2TimeTimeisofgreatimportanceforaccuratenavigation.MotionoftheEarthOnerotationoftheearthaboutitsaxisdefinesaday.Orbitoftheearthaboutthesundefinestheyearandtheseasons.AirNavigation空中领航学3飞行学院PresentationofDateandTimeForflightplanningandnavigationpurposes,weusuallydonotrefertotheyearorthemonthbutonlythedateofthemonthfortheday,followedbythetimeinhoursandminutes.DateandTimeGroupsForaeronauticalpurposes,weusedateandtimegroupstoexpresstime,withthesix-figuregroupbeingthemostcommon.Inallinstances,thelargesttimeunitcomesfirst,followedbyeachsuccessiveunit.Foraneight-figuredateandtimegroup,09301545•thefirsttwonumbersrefertothemonth(September);•thesecondtwonumbersrefertotheday(30th)•thelastfournumbersrefertothehoursandminutes(15:45).YYMMDDHHMMAirNavigation空中领航学4飞行学院TimeandArcofLongitudeLMTAirNavigation空中领航学5飞行学院RelationshipBetweenTimeandArcofLongitudeArcTime360°24hr15°1hr1°4min15´1min1´4sAirNavigation空中领航学6飞行学院DifferentTypesofTimeLocalMeanTime(LMT)Localmeantime(LMT)usesthesunasitscelestialorheavenlyreferencepointandthelocalmeridianoflongitudesasitsterrestrial(earth)referencepoint.CoordinatedUniversalTime(FormerlyGMT)UTCisthelocalmeantimeatthemeridianoflongitudethatrunsthroughtheobservatoryatGreenwichLondon.AirNavigation空中领航学7飞行学院TheGreenwichmeridianislongitude0ºE/Wandisknownastheprimemeridian.Becauseallofournavigation,flightplanningandradiocommunicationsareinUTC,weneedtobeabletoconvertquicklyandaccuratelyfromwhatevertimeweareusingintoUTC,andviceversa.Longitudeeast,universalleast.Longitudewest,universalbest.AirNavigation空中领航学8飞行学院Standard(orLocal)TimeAustraliaissubdividedintoarbitrarytimezones:EasternStandardTime(EST)isusedintheeasternstatesofAustralia.ESTis10hraheadofUTC.CentralStandardTime(CST)isusedinthecentralstatesofAustralia.CSTis9hr30minaheadofUTC.WesternStandardTime(WST)isusedinWesternAustralia.WSTis8hraheadofUTC.AirNavigation空中领航学9飞行学院SummerTimeTotakeadvantageofthelongerdaylighthoursandthebetterweatherinsummer,inmanyplacesaroundtheworldtheclocksareputforward,usuallybyonehour.InsomeAustralianstates,thisoccursbetweenOctoberandMarch,asnotifiedbyNOTAMorpublishedinthemedia.EST=UTC+10hr.ESuT=UTC+11hr.CST=UTC+9hr30min.CSuT=UTC+10hr30min.AirNavigation空中领航学10飞行学院InternationalDateLineItisbasicallythe180°meridian,withminorexcursionstokeepgroupsofislandstogether.AirNavigation空中领航学11飞行学院HorizonHorizonAstronomicalTimesAirNavigation空中领航学12飞行学院CalculatingBeginningofDaylightBeginningofdaylightinthesouthernhemisphereCalculatingBeginningofDaylightAirNavigation空中领航学13飞行学院CalculatingEndofDaylightEndofdaylightinthesouthernhemisphereAirNavigation空中领航学14飞行学院CalculatingEndofDaylightNote:Rememberthatdaylightcanendearlierthanthetimeextractedfromtheappropriategraphforanumberofreasons,includingsignificantcloudcover,poorvisibilityandhighgroundtothewestofanaerodrome.Makeallowancesforthesewhenplanningaflightthatmayfinishneartheendofdaylight.AirNavigation空中领航学15飞行学院CalculatingEndofDaylightNote:Thenormaloperationalrequirementisthatyoumustplantoarriveatleast10minbeforetheendofdaylight.Thisisalegalrequirement;however,commonsenseshouldencourageyoutoincreasethistimeonlongjourneysoronflightswhereitisdifficulttoaccuratelyestimateyourtimeofarrival,suchaswithpoorweatherenrouteoratthedestination.AirNavigation空中领航学16飞行学院SummaryofOperationalTimeProblems•IngeneraldothefundamentalworkinginUTC.•Ifnecessary,convertbackintotherequiredlocalstandardtimeorlocalmeantime.•Alwaysincludethedate,whengiven,inyourcalculations.Keepitclear,orderly,logicalandsimple.AirNavigation空中领航学17飞行学院