The NASA Air Traffic Management Ontology

NASA/TM—2017-219526

The NASA Air Traffic Management Ontology TechnicalDocumentation Richard M. Keller Ames Research Center, Moffett Field, California

June2017

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Acknowledgments

ThisworkwasfundedbytheNationalAviationandSpaceAdministrationundertheAviationOperationsandSafetyProgram.MysincerethankstoMeiWeiandShubhaRanjan,whocontributedlonghourstosoftwaredevelopmentfortheATMOntology,andtoMichelleEshow,theleadfortheSherlockAviationDataWarehouseteam,whogenerouslysupported,encouraged,andcontributedefforttowardthisactivityfromitsinception.

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Abstract

ThisdocumentisintendedtoserveascomprehensivedocumentationfortheNASAAirTrafficManagement(ATM)Ontology.TheATMOntologyisaconceptualmodelthatdefineskeyclassesofentitiesandrelationshipspertainingtotheUSNationalAirspaceSystem(NAS)andthemanagementofairtrafficthroughthatsystem.AwidevarietyofclassesarerepresentedintheATMOntology,includingclassescorrespondingtoflights,aircraft,manufacturers,airports,airlines,airroutes,NASfacilities,airtrafficcontroladvisories,weatherphenomena,andmanyothers.TheOntologycanbeusefulinthecontextofavarietyofinformationmanagementtasksrelevanttoNAS,includinginformationexchange,dataqueryandsearch,informationorganization,informationintegration,andterminologystandardization.

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TableofContents

1 Introduction.....................................................................................................................11.1 DocumentStructure...............................................................................................................11.2 DocumentTerminologyandConventions...............................................................................1

2 AirspaceStructuresandFacilities.....................................................................................32.1 nas:NASfacility........................................................................................................................32.1.1 nas:ATCSCC.............................................................................................................................32.1.2 nas:ATCT.................................................................................................................................32.1.3 nas:ARTCC...............................................................................................................................3

2.1.3.1 nas:ARTCCtier....................................................................................................................................42.1.4 nas:TRACON............................................................................................................................4

2.2 nas:AirspaceInfrastructureComponent...................................................................................42.3 nas:Sector...............................................................................................................................52.3.1 nas:AirspaceLayer...................................................................................................................5

2.4 atm:AircraftFlowCapacity.......................................................................................................62.4.1 atm:AircraftCapacity...............................................................................................................6

2.4.1.1 data:FixCapacity................................................................................................................................62.4.1.2 data:SectorCapacity...........................................................................................................................6

2.4.2 atm:AircraftFlow.....................................................................................................................72.4.2.1 data:FixFlow......................................................................................................................................72.4.2.2 data:SectorFlow.................................................................................................................................7

2.5 IllustrativeFigures..................................................................................................................8

3 Navigation:Routes,Fixes,ArrivalandDepartureProcedures...........................................93.1 atm:NavigationElement..........................................................................................................93.2 atm:NavElementContainer.....................................................................................................93.3 atm:NavigationPath................................................................................................................93.4 atm:PlannedFlightRoute.......................................................................................................103.5 nas:AirspaceRoute................................................................................................................103.5.1 nas:FederalAirway................................................................................................................11

3.5.1.1 nas:RNAVroute................................................................................................................................113.5.1.1.1 nas:QRoute...............................................................................................................................113.5.1.1.2 nas:TRoute................................................................................................................................11

3.5.1.2 nas:VORroute..................................................................................................................................113.5.1.2.1 nas:Jetroute..............................................................................................................................123.5.1.2.2 nas:VictorRoute........................................................................................................................12

3.5.2 nas:RadialRoute....................................................................................................................123.5.3 nas:SIDSTARroute.................................................................................................................12

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3.5.3.1 nas:AirportRoute.............................................................................................................................123.5.3.2 nas:CommonRoute..........................................................................................................................123.5.3.3 nas:TransitionRoute........................................................................................................................13

3.6 atm:NavigationSubPath........................................................................................................133.6.1 atm:FlightPlanSegment........................................................................................................133.6.2 atm:AirspaceRouteSegment.................................................................................................13

3.7 atm:AircraftTrackPoint.........................................................................................................133.8 atm:ActualFlightRoute..........................................................................................................143.9 atm:NavigationFix................................................................................................................143.9.1 atm:AbsoluteFix....................................................................................................................14

3.9.1.1 atm:intersectionFix..........................................................................................................................153.9.1.2 atm:LatLonFix..................................................................................................................................15

3.9.1.2.1 atm:GPSfix................................................................................................................................153.9.1.2.2 atm:NRSfix................................................................................................................................15

3.9.1.3 atm:MeterFix...................................................................................................................................153.9.1.4 atm:NavaidFix..................................................................................................................................15

3.9.1.4.1 atm:NDBfix...............................................................................................................................163.9.1.4.2 atm:TACANfix...........................................................................................................................163.9.1.4.3 atm:VORfix................................................................................................................................16

3.9.1.4.3.1 atm:AirportFix....................................................................................................................163.9.2 atm:RelativeFix.....................................................................................................................16

3.9.2.1 atm:FRDfix.......................................................................................................................................173.10 nas:SIDSTAR......................................................................................................................173.10.1 nas:SID..................................................................................................................................173.10.2 nas:STAR...............................................................................................................................173.10.3 atm:SIDSTARtraverse............................................................................................................18

3.11 IllustrativeFigures.............................................................................................................18

4 TrafficManagementInitiatives.......................................................................................224.1 atm:TrafficManagementInitiative.........................................................................................224.1.1 atm:AirspaceFlowProgramTMI.............................................................................................234.1.2 atm:GroundDelayProgramTMI.............................................................................................234.1.3 atm:GroundStopTMI.............................................................................................................234.1.4 atm:MilesInTrailTMI.............................................................................................................244.1.5 atm:ReRouteTMI..................................................................................................................24

4.2 atm:TFMcontrolElement.......................................................................................................244.3 atm:AirportSpec...................................................................................................................254.4 atm:FlightSpec......................................................................................................................254.5 atm:RerouteSegment...........................................................................................................264.6 atm:DelayModel...................................................................................................................264.7 gen:NumericParameter........................................................................................................274.7.1 gen:FloatParameter..............................................................................................................27

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4.7.2 gen:IntegerParameter..........................................................................................................284.7.2.1 atm:PopupFactor.............................................................................................................................284.7.2.2 atm:ProgramArrivalRate..................................................................................................................28

4.8 atm:NumericParameterContainer.........................................................................................284.8.1 atm:PopupFactorContainer..................................................................................................284.8.2 atm:ProgramArrivalRateContainer.......................................................................................28

4.9 atm:PopupFactorSequence...................................................................................................294.10 atm:ProgramArrivalRateSequence....................................................................................294.11 IllustrativeFigures.............................................................................................................29

5 Operations:Flight,Carrier,andAircraft...........................................................................325.1 atm:Flight.............................................................................................................................325.2 atm:CrewMember................................................................................................................335.3 eqp:AviationServiceProvider.................................................................................................335.3.1 nas:AirCarrier........................................................................................................................345.3.2 nas:AviationIndustryManufacturer......................................................................................34

5.3.2.1 nas:AirframeManufacturer..............................................................................................................345.3.2.2 nas:AircraftEngineManufacturer.....................................................................................................34

5.3.3 nas:GovernmentAviationServiceProvider............................................................................345.4 eqp:EngineeredSystem.........................................................................................................345.4.1 eqp:DecomposableSystem...................................................................................................35

5.4.1.1 eqp:AircraftSubsystem....................................................................................................................355.4.1.1.1 eqp:AircraftCommunicationsSystem........................................................................................355.4.1.1.2 eqp:AircraftEngine....................................................................................................................35

5.4.1.1.2.1 eqp:EngineType.................................................................................................................365.4.1.1.3 eqp:AircraftNavigationSystem..................................................................................................365.4.1.1.4 eqp:ElectricalPowerSystem......................................................................................................36

5.4.1.2 eqp:NavigationAid...........................................................................................................................365.4.2 eqp:UnitAssembly.................................................................................................................36

5.4.2.1 eqp:BallBearing...............................................................................................................................365.4.3 eqp:Aircraft...........................................................................................................................37

5.4.3.1 eqp:AircraftModel...........................................................................................................................375.4.3.2 eqp:AircraftType..............................................................................................................................385.4.3.3 eqp:AircraftWakeCategory..............................................................................................................385.4.3.4 eqp:AircraftWeightClass..................................................................................................................39

5.5 IllustrativeFigures................................................................................................................39

6 AirportandSurfaceOperations.......................................................................................416.1 nas:Airport...........................................................................................................................416.1.1 nas:InternationalAirport.......................................................................................................42

6.1.1.1 nas:CanadianAirport........................................................................................................................426.1.2 nas:USairport........................................................................................................................42

6.1.2.1 nas:CONUSairport...........................................................................................................................42

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6.1.2.2 nas:NonCONUSairport.....................................................................................................................426.2 data:AirportData..................................................................................................................436.2.1 data:WITIproperty................................................................................................................44

6.3 nas:AirportInfrastructureComponent...................................................................................446.4 nas:AirportServiceVehicle.....................................................................................................456.4.1 nas:DeicingTruck...................................................................................................................456.4.2 nas:RefuelingTruck...............................................................................................................45

6.5 nas:ATCT...............................................................................................................................456.6 nas:RampTower....................................................................................................................456.7 nas:DeicingPad.....................................................................................................................466.7.1 nas:DeicingQueue.................................................................................................................46

6.8 nas:Gate...............................................................................................................................466.9 nas:PhysicalRunway.............................................................................................................466.9.1 data:RunwayStatusData.......................................................................................................47

6.10 nas:OperationalRunway....................................................................................................476.11 nas:Taxiway......................................................................................................................486.11.1 atm:Taxipath.........................................................................................................................48

6.12 nas:Terminal.....................................................................................................................486.13 IllustrativeFigures.............................................................................................................49

7 Weather..........................................................................................................................517.1 data:MeteorologicalCondition..............................................................................................517.1.1 data:ASPMmeteorologicalCondition....................................................................................517.1.2 data:METARreport................................................................................................................52

7.1.2.1 data:METARreportingStation..........................................................................................................527.1.2.1.1 nas:StandAloneWeatherStation...............................................................................................52

7.1.3 data:TAFmeteorologicalCondition........................................................................................527.1.3.1 data:TAFreport................................................................................................................................53

7.2 data:MetCondition...............................................................................................................537.2.1 data:SkyCondition.................................................................................................................53

7.2.1.1 data:CloudLayer...............................................................................................................................547.2.1.1.1 data:CloudLayerProfile.............................................................................................................54

7.2.2 data:SurfaceWindCondition.................................................................................................547.2.3 data:WeatherCondition........................................................................................................557.2.4 data:VisibilityCondition........................................................................................................55

7.2.4.1 nas:RunwayVisibleRangeMeasurement.........................................................................................567.3 IllustrativeFigures................................................................................................................57

8 Sequences,Subsequenes,SequencedItems....................................................................598.1 gen:Sequence.......................................................................................................................598.1.1 gen:SubSequence.................................................................................................................60

8.2 gen:SequencedItem..............................................................................................................61

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9 Temporal/Spatial............................................................................................................629.1 data:IntervalData.................................................................................................................629.2 gen:TimeInterval..................................................................................................................629.3 nas:NASday..........................................................................................................................629.4 nas:NAShour.........................................................................................................................639.5 gen:Location.........................................................................................................................639.5.1 gen:GeographicRegion.........................................................................................................63

9.5.1.1 gen:Region2D..................................................................................................................................639.5.1.1.1 gen:CircularRegion...................................................................................................................649.5.1.1.2 gen:Polygonal2DRegion............................................................................................................64

9.5.1.2 gen:Region3D..................................................................................................................................649.5.1.2.1 gen:ShearSidedPolygonalVolume.............................................................................................64

9.5.2 gen:PointLocation.................................................................................................................649.5.2.1 gen:PolygonBoundary.....................................................................................................................65


10 Appendices..................................................................................................................67AppendixA References....................................................................................................................67AppendixB OntologyNamespaces..................................................................................................68

B.1 Namespacegen:Generic,domain-independentclasses.......................................................68B.2 Namespaceeqp:Equipment-relatedclasses.........................................................................68B.3 Namespacenas:NationalAirspaceSystem-relatedclasses..................................................69B.4 Namespaceatm:AirTrafficManagement-relatedclasses....................................................70B.5 Namespacedata:Data-specificclasses.................................................................................72

AppendixC SubsumptionHierarchy................................................................................................73AppendixD NotesontheOntology.................................................................................................76AppendixE OrganizationofOntologyFiles.....................................................................................77AppendixF Acronyms......................................................................................................................79

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1 Introduction

ThisdocumentdescribestheNASAAirTrafficManagement(ATM)Ontology.TheATMOntologydefineskeyclassesofentitiespertainingtotheUSNationalAirspaceSystem(NAS)andthemanagementofairtrafficthroughthatsystem.AwidevarietyofclassesarerepresentedintheATMOntology,includingclassescorrespondingtoflights,aircraft,manufacturers,airports,airlines,airroutes,NASfacilities,airtrafficcontroladvisories,weatherphenomena,andmanyothers.

ThemotivationfordevelopingthisontologystemsfromNASA’Sneedtointegrateheterogeneousformsofaviationdataforuseinaeronauticsresearch.Toaccomplishdataintegration,weappliedsemanticintegrationtechniques[1,2]thatdependuponexistenceofcommonontologytoserveasanintegrativedatamodel.DatafrommultipleaviationsourcesweretransformedintoATMOntologyinstancesandloadedintoatriplestore.Queriesagainstthetriplestorecouldthenbeexecutedacrosstheintegrateddataandresultscouldbedeliveredtousers.ThisdocumentisintendedtoserveascomprehensivedocumentationfortheATMOntology;otherdocumentsaremoreappropriateforahigh-leveloverviewoftheOntologyanditscontextofitsusewithinNASA[3-6].

TheOntologyisformattedasasetofOWL(WebOntologyLanguage)files[7],andbasicknowledgeofOWL,RDF[8](ResourceDescriptionFramework),andRDFS[9](RDFSchema)ispresumedinthisdocument.

1.1 DocumentStructure

MostofthisdocumentisdevotedtodescribingclassesdefinedintheATMOntology,alongwiththeirobjectproperties(i.e.,linkstootherclasses)anddatatypeproperties(i.e.,classattributes).Theclasseshavebeenorganizedintoeightmajorsectionsdescribingthematically-relatedsetsofclasses;eachoftheseclassesisdescribedinitsownsubsectionofthedocument:

• AirspaceStructuresandFacilities• Navigation:Routes,Fixes,ArrivalandDepartureProcedures• TrafficManagementInitiatives• Operations:Flight,Carrier,andAircraft• AirportandSurfaceOperations• Weather• Sequences,Subsequences,SequencedItems• Temporal/Spatial

Notethattheorganizationofthisdocumentintosectionsandsubsectionsisbasedonpedagogicalconsiderationsandonmaximizingunderstandability;thisstructuredoesnotnecessarilymatchtheATMOntology’ssubsumption(i.e.subclass)hierarchydetailedinAppendixCorthepartitioningofclassesdefinedbytheontologynamespacestructuredetailedinAppendixB.Attheendofeachmajorsection,thereisasubsectiondevotedtoillustrativefiguresshowinghowtheclassesworktogetherandareusedinpractice.

1.2 DocumentTerminologyandConventions

Ingeneral,wefollowOWLterminologyandusetheterm‘class’ratherthan‘entity’,’resource’,‘object’,or‘concept’.Similarly,weusetheterms‘objectproperty’and‘datatypeproperty’ratherthantheterms‘relation’and‘attribute’.

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Classdescriptionsinthisdocumentareformattedasfollows:

classname

• Description: class description text

• Superclasses: o superclass1 o superclass2 o …

• subclasses: o subclass1 o subclass2 o …

• object properties o propertyname1 [range1]: property description text o propertyname2 [range2]: property description text o …

• datatype properties o propertyname1 [datatype1]: property description text o propertyname2 [datatype2]: property description text o …

where:

Ø classname represents the domain of propertynamei

Ø rangei represents the range of propertynamei

Ø datatypei = one of {‘integer’, ‘float’, ‘datetime’, ‘string’}, representing the datatype

of propertynamei Note: if present, the special syntax ‘string: “val1”, “val2”,…, “val3n” ’ indicates a string whose value is constrained to take one of the n listed values; otherwise the string value is unconstrained

all bulleted items are optional except the description.

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2 AirspaceStructuresandFacilities

TheclassesinthissectiondefinevariousstructuresandfacilitiesthatconstitutekeycomponentsoftheNAS.Alsoincludedareclassestomeasuretheaircraftflowandcapacitypassingthroughthesestructures.

2.1 nas:NASfacility

• Description:ThesetofFAAfacilitiesinvolvedinoperationalairtrafficmanagement.Theobjectpropertynas:hasLOAwithsignifiesthatafacilityhasaLetterofAgreement(LOA)withanotherfacility;thispropertyisusedtoconnectfacilitiestogetherintoatopologythatreflectstheFAAoperationshierarchy.TheFAAATSCC(SystemCommandCenter)isatthetopofthishierarchy;theATSCChasagreementswiththeARTCCs;theARTCCshaveagreementswiththeTRACONS;theARTCCsandTRACONshaveagreementswiththeairports.

• Subclasses:o nas:Airporto nas:ARTCCo nas:ATCSCCo nas:ATCTo nas:TRACON

• Objectproperties:o nas:hasLOAwith[nas:NASfacility]:ThispropertylinksaNASfacilitytoanotherNASfacilitywhen

thereisaletterofagreement(LOA)inplacebetweenthem.Typically,aLOAisneededwhentwoormoreFAAfacilitiescooperatetoaccomplishflightoperations.Theagreementindicateseachparty’sresponsibilities.

2.1.1 nas:ATCSCC

• Description:AirTrafficControlSystemCommandCenter(ATCSCC)facilityisinchargeofoverallNASoperations.ThereisoneinstanceoftheATCSCCclass:nas:UScommandCenter.

• Superclasses:o nas:NASfacility

2.1.2 nas:ATCT

• Description:AirTrafficControlTower(ATCT)controlsairportdeparturesandarrivals.• Superclasses:

o nas:NASfacility

2.1.3 nas:ARTCC

• Description:AnAirRouteTrafficControlCenterhastrafficmanagementresponsibilityforhigh-altitudeenrouteaircrafttransitingthroughtheNAS.TheadjacencystructureoftheARTCCsisrepresentedbynas:ARTCCtier,whichcapturesCentersthatareproximatetoagivencenter.


• Objectproperties:o nas:hasCenterGeometry[gen:Polygonal2DRegion]:the2-dimensionalboundingregionofthe

ARTCC

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o nas:hasTier[nas:ARTCCtier]:AssociatesanARTCCwiththesetofARTCCsinitsnthleveltier.Tier1includesallARTCCsimmediatelyadjoiningthecentralARTCC;tier2includestier1plusalladjacentARTCCstwostepsawayfromthecentralARTCC.Andsoon.

• Datatypeproperties:o nas:artccID[string]:TheFAA-assigned3-lettercodefortheARTCC

2.1.3.1 nas:ARTCCtier

• Description:Adonut-shapedgeographicalareasurroundingadesignatedcentralARTCC.ThefirsttierincludesalltheARTCCsthatshareaboundarywiththedesignatedARTCC.ThetiertwoARTCCsincludesthoseadjacenttothefirsttierARCCCs.Andsoon.

• Superclasses:o nas:AirspaceInfrastructureComponent

• Objectproperties:o nas:includesARTCC[nas:ARTCC]:LinksthetierwiththeincludedARTCCs.TheARTCCatthecenter

ofthedonutisnotlinked.• Datatypeproperties:

o nas:tierLevel[integer]:Thetierlevelofthistier.ThedegreenumberoftheARTCCtier.Tier1includesallARTCCsimmediatelyadjoiningthecentralARTCC;tier2includesalladjacentARTCCstwostepsawayfromthecentralARTCC.Andsoon.

2.1.4 nas:TRACON

• Description:TheTerminalRadarApproachControl(TRACON)facilitymanagesaircrafttransitingbetweentheairportandtheenrouteCenter,handlingbothairportarrivalsanddepartures.


• Objectproperties:o nas:hasTRACONlayer[nas:AirspaceLayer]:AlinkbetweentheTRACONandthelayersthat

representitsgeographicextent,representedasastackofsingleshear-sidedpolygonalvolumes.• Datatypeproperties:

o nas:hasTRACONcity[string]:ThecitynamewheretheTRACONcommandcenterislocated.o nas:hasTRACONid[string]:TheFAAalphanumericcodefortheTRACON.o nas:hasTRACONname[string]:ThecommonnamefortheTRACON.o nas:hasTRACONstate[string]:ThenameoftheUSstateinwhichtheTRACONcommandcenteris

located.o nas:hasTRACONtype[string:“TRACON”,”TOWER”]:ThetypeofTRACON:Tower-collocated

TRACONorstandaloneTRACONfacility.

2.2 nas:AirspaceInfrastructureComponent

• Description:Thisclassconsistsofairspacestructuresdefinedtocontrol,monitor,ormanageairtraffic.• Superclasses:

o nas:TFMcontrolElement• Subclasses:

o nas:AirspaceLayer

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o nas:AirspaceRouteo nas:ARTCCo nas:ARTCCtiero nas:Sectoro nas:SIDSTAR

§ nas:SID§ nas:STAR

o nas:TRACON

2.3 nas:Sector

• Description:AdefinedvolumeintheairspaceofanARTCCwhoseflighttrafficistypicallycontrolledbyasinglecontroller.Asectorcontainsmultiplelayers,eachofwhichisapolygonalvolumedefinedbyanidenticalsurfaceboundarypolygononthetopandbottom,andverticalsides(calledagen:ShearSidedPolygonalVolume).Thesectorismodeledasaverticalstackofthesevolumesformingatypeofjagged‘layercake’structure.Eachlayerislinkedtothesectorviathepropertynas:hasSectorLayer.Anysectorimmediatelyadjacentto(i.e.,touching)thesectorislinkedviathepropertynas:adjacentSector,andtheARTCCinwhichthesectorislocatedislinkedviathepropertynas:locatedInCenter.


• Objectproperties:o nas:adjacentSector[nas:Sector]:Linkstoanyimmediatelyproximatesectorswithboundaries

thattouchthecurrentsectoro nas:hasSectorLayer[nas:AirspaceLayer]:Linkstoallofthelayerswithinthesectoro nas:locatedInCenter[nas:ARTCC]:LinkstotheuniqueARTCCinwhichthissectorislocated

• Datatypeproperties:o nas:hasSectorID[string]:TheFAA-assignedsectoridentifierthatconsistsoftheARTCCidentifier

concatenatedwithathree-digitnumber.Thisidentifierisingeneraldifferentthanthesectorname.

o nas:hasSectorName[string]:TheFAA-assignedsectorname,analphanumericsectornamethatisingeneraldifferentthanthesectorID.

o nas:tfmsMonitorAlertParameter[integer]:Themaximumnumberofaircraftpermittedinagivensectoratanytime,peragreementbetweenFAAandAirTrafficControllerunion.MAP(MonitorAlertParameter)isaTFMSinputparameter.

2.3.1 nas:AirspaceLayer

• Description:Representsahorizontallayerwithintheairspace,definedbyashear-sidedpolygonwithspecifiedlowandhighaltitudes.Thepropertynas:hasAirspaceLayerGeometrylinksthelayertoarepresentationofthevolumeasagen:ShearSidedPolygonalVolume,whilethepropertynas:airspaceLayerLowAltitudeandnas:airspaceLayerHighAltitudegivetheboundingaltitudesofthetopandbottomofthelayerinfeet.(Thedifferencebetweenthetopandbottomaltitudeshouldbeequaltotheheightoftheshear-sidedpolygonalvolume.)


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• Objectproperties:o nas:hasAirspaceLayerGeometry[gen:ShearSidedPolygonalVolume]:thegeometricvolume

representingtheextentofthesectorlayer• Datatypeproperties:

o nas:airspaceLayerHighAltitude[integer]:theupperaltitudeofthesectorlayero nas:airspaceLayerLowAltitude[integer]:theloweraltitudeofthesectorlayer

2.4 atm:AircraftFlowCapacity

• Description:Asuperclassofdatarelevanttomeasuringtheactualandtheoreticalmaximumnumberofaircraftthatflowthroughanairspacestructureduringsomeintervaloftime,givenweatherandotherairtrafficcontrolconstraints.

• Superclasses:o data:IntervalData

• Subclasses:o atm:AircraftCapacityo atm:AircraftFlow

• Objectproperties:o atm:flowMeasurementRegion[atm:TFMcontrolElement]:Linkstothetrafficmanagement

structurethroughwhichfloworcapacityisbeingmeasuredoranalyzed.

2.4.1 atm:AircraftCapacity

• Description:Aclassrepresentingthecapacityofanairspaceregiontosafelycontainaircraftsimultaneouslytraversingtheregionduringaspecifiedperiodoftime.

• Superclasses:o atm:AircraftFlowCapacity

• Subclasses:o data:FixCapacityo data:SectorCapacity

• Datatypeproperties:o atm:flowCapacity[float]:Thetheoreticalmaximumnumberofaircraftthatcanbesafely

controlledinanairspaceregionduringsomeintervaloftime.

2.4.1.1 data:FixCapacity

• Description:Aclassrepresentingthecapacityofafixtosafelyhandleaircrafttraversingduringaspecifiedperiodoftime.

• Superclasses:o atm:AircraftCapacity

• Note:Thisclassconstrainsatm:flowMeasurementRegiontobeatm:NavigationFixusinganOWLrestriction.

2.4.1.2 data:SectorCapacity

• Description:Aclassrepresentingthecapacityofasectortosafelycontainaircraftsimultaneouslytraversingthesectorduringaspecifiedperiodoftime.

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• Superclasses:o atm:AircraftCapacity

• Note:Thisclassconstrainsatm:flowMeasurementRegiontobenas:SectorusinganOWLrestriction.

2.4.2 atm:AircraftFlow

• Description:Aclassrepresentingtheactualflowofaircraftthroughanairspaceregionoversomeintervaloftime.Forexample,aninstanceofthisclasscouldrepresenttheflowofflightsfromSFOtoORDonaspecificdate,passingthroughaspecificsector.

• Superclasses:atm:AircraftFlowCapacity• Objectproperties:

o atm:includedFlights[atm:FlightSpec]:Linksanaircraftflowtoaspecificationoftheflightsincludedintheflow.

• Datatypeproperties:o atm:aircraftCount[integer]:Thenumberofaircraftflowingthroughanairspaceregionpersome

intervaloftime.

2.4.2.1 data:FixFlow

• Description:Asubclassofdata:AircraftFlowthatmeasuresaircraftflowatafix.• Superclasses:

o atm:AircraftFlow• Note:ThissubclassisspecifiedusinganOWLrestrictionontheatm:flowMeasurementRegionproperty

thatconstrainsitsvaluetobeaninstanceofatm:NavigationFix.

2.4.2.2 data:SectorFlow

• Description:Asubclassofdata:AircraftFlowthatmeasuresaircraftflowatasector.• Superclasses:

o atm:AircraftFlow• Note:ThissubclassisspecifiedusinganOWLrestrictionontheatm:flowMeasurementRegionproperty

thatconstrainsitsvaluetobeaninstanceofnas:Sector.

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2.5 IllustrativeFigures

Figure1:Illustrationofkeyrelationshipsamongselectedairspacestructureandfacilityinstances.Sectornas:ZNYsector075isoneofthesectorslocatedintheNewYorkARTCC(nas:ZNYcenter).Sector075iscomposedoftwostackedhorizontallayersofairspace,eachrepresentedbyashear-sidedpolygonofacertainheight(onlyonepolygonisdepictedinthefigure).SeealsoFigure17fortheexpandedsectorlayerrepresentation.TheZNYARTCChasagreementswiththeFAAcommandcenterandtheNewYorkTRACON,whichinturnhasagreementswitheachoftheairportsinitsterritory.TheZNYTier1structurecontainsallARTCCsthatdirectlyneighbortheZNYARTCC.(Notethatonlyasmallsubsetofinstancesisillustratedinordertokeepthefigureunclutteredandreadable.)

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3 Navigation:Routes,Fixes,ArrivalandDepartureProcedures

Theclassesinthissectiondefinetheroutes,airways,fixes,andarrival/departureproceduresbywhichaircraftnavigatethroughtheNAS.

3.1 atm:NavigationElement

• Description:Thisclassrepresentsthesetofcomponentsthatcanbeusedtospecifyapaththroughtheairspace.Thesecompositionalelementsincludefixes(pointsintheairspace),routes(pre-specifiedpathsthroughtheairspacedefinedbytheFAA),airports,SID/STARtraverses(specificpathsthroughairportdeparture/arrivalnetworks),etc.Thenavigationalelementsareassembledintopathsusingasequence(gen:Sequence)–inparticular,usingthesequencesubclasscalledatm:NavigationPath.(Notethatatm:NavigationPathisalsoatypeofnavigationelementbecausepredefinedpathscanbeplacedinsequenceprecedingorfollowingotherelementstoformapath.)

• Superclasses:o atm:TFMcontrolElement

• Subclasses:o atm:NavigationFixo atm:NavigationPatho atm:NavigationSubPath

• atm:AirspaceRouteSegment• atm:FlightPlanSegment

o atm:SIDSTARtraverseo atm:Airport

3.2 atm:NavElementContainer

• Description:Anavigationelementcontainerisawrapperaroundanexistingnavigationelement(atm:NavigationElement),suchasafixoraroute.Thesecontainerscanbesequencedtogethertorepresentflightpaths(seegen:Sequence,gen:SequencedElement).

• Note:Acontainerconstructisusedsothatthesamenavigationelementcanappearinmultiplesequences.Iftheelementsthemselvesweresequenced,eachelementcouldhaveonlyasingleprecedingorfollowingelementinasequence.Thiswouldprecludeanelementfrombeingsequencedindifferentwaysindifferentsequences.

• Superclasses:o gen:SequencedItem

• Objectproperties:o atm:hasNavElement[atm:NavigationElement]:Linksacontainerforanavigationalelementto

theelementcontained.

3.3 atm:NavigationPath

• Description:Anorderedsequenceofnavigationelementcontainers(atm:NavElementContainer)representinganarbitrarypaththroughtheairspace.

• Superclasses:o atm:NavigationElemento gen:Sequence

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• Subclasses:o atm:PlannedFlightRouteo nas:AirspaceRoute

3.4 atm:PlannedFlightRoute

• Description:Aplannedflightrouteisanorderedsequenceofnavigationelementcontainers(atm:NavElementContainer)thatcontainnavigationelements(atm:NavigationElement)thepilotintendstotraverseenroutefromorigintodestinationairport.

• Superclasses:o atm:FlightSequenceo atm:NavigationPath

• Objectproperties:o atm:planFilingDay[nas:NASday]:LinkstothedaywhentheflightplanwasfiledwiththeFAA.

• Datatypeproperties:o atm:flightPlanETA[dateTime]:Theestimatedtimeofarrivalspecifiedintheflightplan.o atm:flightRouteString[string]:Astringthatprovidestherouteofflightproposedinaflightplan.

Syntactically,thestringshowsapathoffixes,airways,SIDs,andSTARs,separatedbyeitheroneortwodots.Thisstringisparsedtocreateanequivalentontologyrepresentation:anorderedsequenceofnavigationelementsthatconstitutetheplannedflightroute.

o atm:planFilingTime[dateTime]:ThetimethattheflightplanwasfiledwiththeFAA.o atm:planGapAfterSequenceElement[integer]:Indicatesthelocationofagapintheflightplan

sequenceduetonon-parsable/uninterpretableelementsintheflightroutestring.

3.5 nas:AirspaceRoute

• Description:AnFAA-definedsequenceofnavigationelementsspecifyingapaththroughtheairspace.Anairspacerouteisasubclassofatm:NavigationPath,whichisamoregeneralclassofarbitraryairspacepaths;nas:AirspaceRoutecontainsonlytheroutesdefinedbyFAA,includingthespecificsubclassesofroutesdefinedbelow.

• Superclasses:o atm:NavigationPatho nas:AirspaceInfrastructureComponent

• Subclasses:o nas:FederalAirway

§ nas:RNAVroute• nas:QRoute• nas:TRoute

§ nas:VORroute• nas:JetRoute• nas:VictorRoute

o nas:RadialRouteo nas:SIDSTARroute

§ nas:AirportRoute§ nas:CommonRoute

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§ nas:TransitionRoute• Datatypeproperties:

o nas:routeID[string]:FAAalphanumericidentifierassignedtotheroute/airway.

3.5.1 nas:FederalAirway

• Definition:AnairspaceroutethatisdefinedbyFAAandcanbefiledaspartofaflightplan:ajetroute,aQ-route,aT-Route,aVictorroute.

• Superclasses:o nas:AirspaceRoute

• Subclasses:o nas:RNAVrouteo nas:VORroute

3.5.1.1 nas:RNAVroute

• Definition:AnRNAV(RandomNavigation)routeisdefinedrelativetoanetworkofexistingground-basednavigationbeacons.RNAVallowsanaircrafttochooseanycoursewithinthenetwork,ratherthannavigateusingonlypoint-to-pointroutesdefinedbythebeacons.

• Superclasses:o nas:FederalAirway

• Subclasses:o nas:QRouteo nas:TRoute

3.5.1.1.1 nas:QRoute

• Definition:AhighaltitudeRNAVairwayroute.(RNAVroutesallowanaircrafttochooseanycoursewithinanetworkofnavigationbeacons,ratherthannavigatedirectlytoandfromthebeacons.)

• Superclasses:o nas:RNAVroute

3.5.1.1.2 nas:TRoute

• Definition:AlowaltitudeRNAVairwayroute.(RNAVroutesallowanaircrafttochooseanycoursewithinanetworkofnavigationbeacons,ratherthannavigatedirectlytoandfromthebeacons.)

• Superclasses:o nas:RNAVroute

3.5.1.2 nas:VORroute

• Definition:VORrouteisdefinedrelativetoanetworkofexistingground-basedVORnavigationbeacons.VORroutesconsistofpoint-to-pointsegments,wherethepointsaredefinedbythebeacons.MoremodernRNAVroutesallowanypathwithinthenetwork,notlimitedtoVOR-to-VORsegments.

• Superclasses:o nas:FederalAirway

• Subclasses:o nas:Jetroute

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o nas:VictorRoute

3.5.1.2.1 nas:Jetroute

• Definition:Ahighaltitudeairwaybasedonground-basedVORsensorlocations.• Superclasses:

o nas:VORroute

3.5.1.2.2 nas:VictorRoute

• Definition:Alowaltitudeairwaybasedonground-basedVORsensorlocations.• Superclasses:

o nas:VORroute

3.5.2 nas:RadialRoute

• Definition:Aroutethatfollowsaspecifiedradialpathemanatingfromagivenfix.• Superclasses:

o nas:AirspaceRoute• Objectproperties:

o atm:radialFix[atm:NavigationFix]:Linkstothefixthroughwhichtheradialroutepasses.• Datatypeproperties:

o atm:radialAngle[integer]:Theangle(indegrees)thatdefinestheradialroute'sangularpositionwithrespecttothedefinedfix.

3.5.3 nas:SIDSTARroute

• Definition:AroutethatdefinesaSIDorSTAR.• Superclasses:

o nas:AirspaceRoute• Subclasses:

o nas:AirportRouteo nas:CommonRouteo nas:TransitionRoute

3.5.3.1 nas:AirportRoute

• Definition:AroutewithinaSIDorSTARthatconnectsthecommonroutetooneofmultipleairportsthatusetheSID/STAR.

• Superclasses:o nas:SIDSTARroute

• Objectproperties:o nas:arrivalRouteAirport[nas:Airport]:LinkstotheSTARairportforwhichthisrouteisdestined.o nas:departureRouteAirport[nas:Airport]:LinkstotheSIDairportfromwhichthisroute

originated.

3.5.3.2 nas:CommonRoute

• Definition:ThebackboneportionofaSIDorSTARthatisflownbyallaircraft.

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3.5.3.3 nas:TransitionRoute

• Definition:AroutewithinaSIDorSTARthatfeedsaircraftintooroutfromthecommonrouteoftheSID/STAR.Inotherwords,thetransitionrouteisafeederroutefromtheenroutesegmentofaflightintotheheartofaSTARforarrival;oranexitroutefromaSIDfunnelingflightstotheirappropriateinitialjetroutesfortheenroutesegmentofflight.


3.6 atm:NavigationSubPath

• Description:Acontiguoussubportionofanexistingdefinednavigationpath.Seegen:SubSequence.• Superclasses:

o atm:NavigationElemento gen:SubSequence

• Subclasses:o atm:FlightPlanSegmento atm:AirspaceRouteSegment

3.6.1 atm:FlightPlanSegment

• Description:Acontiguoussubportionofanexistingdefinedflightplan.• Superclasses:

o atm:NavigationSubPath

3.6.2 atm:AirspaceRouteSegment

• Description:Acontiguoussubportionofanexistingdefinedairspaceroute.• Note:Aflightplanwilltypicallyincludeoneormorecontiguoussubsectionsofexistingairspaceroutes.• Superclasses:

o atm:NavigationSubPath

3.7 atm:AircraftTrackPoint

• Description:Apointduringaflightwherevariousflightparametersarecapturedandsent(viatransponder)toFAAcomputers.

• ObjectProperties:o atm:aircraftFix[atm:navigationFix]:Linksanaircrafttrackpointwithitsassociatednavigationfix.o atm:reportingDay[nas:NASday]:Alinkbetweenanaircrafttrackpointandthedayduringwhich

anenrouteaircrafttraversedthatpointandreporteditsposition,speed,andheading.• DatatypeProperties:

o atm:groundspeed[integer]:Thereportedgroundspeedatanaircrafttrackpoint.o atm:heading[float]:Theaircraftheadingatthetrackpoint:anumberbetween0.01and360.0

indicatingtheangularheadingwithrespecttoNorth.

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o atm:reportingTime[dateTime]:Thetimewhenanenrouteaircraftpassedthroughatrackpointandreporteditsposition,speed,andheading.

3.8 atm:ActualFlightRoute

• Description:Aflighttrajectory,i.e.,asequenceoftrackpoints(atm:AircraftTrackPoint),asdeterminedbyflighttracksurveillancedata.Seegen:Sequence.

3.9 atm:NavigationFix

• Description:Adesignatedpointonorabovethesurfaceoftheearthusedforaeronauticalnavigation.Fixesaresplitintosubclassesofabsoluteandrelativefixes.Anabsolutefixisdefinedexplicitlyintermsofaspecifiedlatitude/longitude/altitude.Arelativefixisdefinedinrelationtoanabsolutefix.Ingeneral,fixesareeithernamed(byFAAorICAO)orunnamed.Differentsubclassescapturedifferenttypesoffixes(e.g.,intersectionfixes,navaidfixes,meterfixes).

• Superclasses:o atm:NavigationElement

• Subclasses:o atm:AbsoluteFix-Afixbasedonsomeestablishedglobalmeasuringscheme.

§ atm:intersectionFix§ atm:LatLonFix

• atm:GPSfix• atm:NRSfix

§ atm:MeterFix§ atm:NavaidFix

• atm:NDBfix• atm:TACANfix• atm:VORfix

o atm:AirportFixo atm:RelativeFix-Afixdefinedinrelationtoanotherfix.

§ atm:DMEfix• atm:FRDfix

• Objectproperties:o atm:locatedInSector[nas:Sector]:Linkstotheuniquesectorinwhichthisfixislocated.

• Datatypeproperties:o atm:fixId[string]:Anon-uniqueFAAidentifierforafix.WhencombinedwithafixICAOcode,it

definesauniquefixworldwide.Often,butnotalways,thefixIdisidenticaltothefixName.o atm:fixName[string]:AuniqueFAAidentifierforafixthatcanbefiledaspartofaflightplan.The

fixnameconceptuallyrepresentstheworldwide-uniquecombinationofaFixIDandICAOcode.Often,butnotalways,thefixIdisidenticaltothefixName.

3.9.1 atm:AbsoluteFix

• Definition:Afixbasedonsomeestablishedglobalmeasuringscheme.• Superclasses:

o atm:NavigationFix

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o gen:PointLocation

3.9.1.1 atm:intersectionFix

• Definition:Anavigationfixdefinedbytheintersectionoftwoairspaceroutes.• Superclasses:

o atm:AbsoluteFix

3.9.1.2 atm:LatLonFix

• Definition:Anavigationfixbasedonlatitude/longitudecoordinates.• Superclasses:

o atm:AbsoluteFix

3.9.1.2.1 atm:GPSfix

• Definition:AnavigationfixdefinedbyGPScoordinates.• Superclasses:

o atm:LatLonFix

3.9.1.2.2 atm:NRSfix

• Definition:TheNRSisasystemofwaypointsdevelopedforusewithintheUnitedStatesforflightplanningandnavigationwithoutreferencetogroundbasednavigationalaids.TheNRSwaypointsarelocatedinagridpatternalongdefinedlatitudeandlongitudelines.NRSwaypointnamesarecomposedoftwolettersfollowedbytwonumbers,followedbyasingleletter.ThefirstandsecondcharactersofNRSwaypointsaretheFIRidentifierfortheUnitedStates(“K”)andtheFIRsubdivision,orARTCCcenterinwhichthewaypointislocated(e.g.“D”forDenverARTCC).Thethirdandfourthcharactersareanumbergrouprepresentingthelatitudeofthewaypoint.Thesenumbersbeginattheequatorwith00andadvancesnorthandsouthfrom01to90andcorrespondtoevery10minutesoflatitudeandrepeatingevery15°.ThefinalcharacterintheNRSwaypointisaletterrepresentingthelineoflongitudeforwhichthewaypointislocated.ThisidentifierstartsattheprimemeridianmovingwesttoeastandusesthelettersAtoZwhilerepeatingevery26°.Todate,thecurrentdensityoftheNRSgridisonewaypointspacedevery30minutesoflatitudeandevery2°oflongitude.

• Superclasses:o atm:LatLonFix

3.9.1.3 atm:MeterFix

• Definition:Afixdefinedasapointintheterminalairspacethroughwhichflightsaremeteredbyairtrafficcontrolonapproach.

• Superclasses:o atm:AbsoluteFix

3.9.1.4 atm:NavaidFix

• Definition:Afixbasedonthelocationofaground-basedNavigationAid(Navaid)installation.• Superclasses:

o atm:AbsoluteFix

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3.9.1.4.1 atm:NDBfix

• Definition:Afixbasedonthelocationofaground-basednon-directionalradiobeacon(NDB)installation.NDBsignalsfollowthecurvatureoftheEarth,sotheycanbereceivedatmuchgreaterdistancesatloweraltitudes,amajoradvantageoverVOR.However,NDBsignalsarealsoaffectedmorebyatmosphericconditions,mountainousterrain,coastalrefractionandelectricalstorms,particularlyatlongrange.

• Superclasses:o atm:NavaidFix

3.9.1.4.2 atm:TACANfix

• Definition:Afixbasedonthelocationofaground-basedTACAN(TACticalAirNavigation)installation.• Superclasses:

o atm:NavaidFix

3.9.1.4.3 atm:VORfix

• Definition:Afixbasedonthelocationofaground-basedVOR(VHFOmniDirectionalRadioRange)installation.

• Superclasses:o atm:NavaidFix

3.9.1.4.3.1 atm:AirportFix

• Definition:Asubclassofnavigationfixcorrespondingtofixesassociateddirectlywithagroundreferencepointthatisanairport.

• Superclasses:o atm:VORFix

3.9.2 atm:RelativeFix

• Definition:Afixdefinedinrelationtoanotherfix.• Superclasses:

o atm:NavigationFix• Subclasses:

o atm:FRDfix• Objectproperties:

o atm:referenceFix[atm:AbsoluteFix]:Linksarelativefixtotheabsolutefixthatservesasthebasisforitslocation.(Arelativefixpositionisdefinedrelativetoanabsolutefixposition,e.g.asavectoroffsetfromtheabsolutefix.)

• Datatypeproperties:o atm:relativeAngle[integer]:Theangulardirectionindegrees(1-360)ofarelativefixwithrespect

toitsdefiningabsolutefix.o atm:relativeDistance[integer]:Thedistance(innauticalmiles)betweenarelativefixandits

defining(absolute)fix.

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3.9.2.1 atm:FRDfix

• Definition:AFixRadialDistance(FRD)fixislocatedaspecifieddistancefromaground-basednavaid,anamedfix,oranairport,alongagivenradialvector.

• Superclasses:o atm:RelativeFix

3.10 nas:SIDSTAR

• Description:Thisclassrepresentsthegeneralizedstructureofanairportdeparture(nas:SID)orarrivalroute(nas:STAR).SIDsandSTARsaresetsofpredefinedmacro-routesthataircraftfollowintheimmediatevicinityofanairport,eitherondepartureorarrival.SIDsandSTARshaveasimilarstructure:theyarecomposedofacommonroutethatallaircraftfollow,plustwosetsofdivergingorconvergingroutes(transitionroutesandairportroutes)thatdirecttheaircrafttoorfromthecommonroute.


• Subclasses:o nas:SIDo nas:STAR

• Objectproperties:o nas:hasAirportRoute[AirportRoute]:ForSTARs,thesetofroutesthataircraftcanfollowtoa

destinationairportafterleavingthecommonroute;forSIDs,thesetofroutesthataircraftcanfollowfromanoriginatingairporttojointhecommonroute.

o nas:hasCommonRoute[CommonRoute]:AroutethatisflownbyallaircraftnavigatingtheSIDorSTAR.

o nas:hasTransitionRoute[TransitionRoute]:ForSTARs,thesetofroutesthataircraftcanfollowbeforecommencingthecommonroute;forSIDs,thesetofroutesthataircraftcanfollowafterflyingthecommonroute.

• Datatypeproperties:o nas:sidstarID[string]:TheFAAidentifierfortheSIDorSTAR.Typically,butnotuniformly,5alpha

charactersplusarevisiondigit.

3.10.1 nas:SID

• Description:ASID(StandardInstrumentDeparture)isanairtrafficcontrolcodeddepartureprocedurethathasbeenestablishedatcertainairportstosimplifyclearancedeliveryprocedures.

• Superclasses:o nas:SIDSTAR

3.10.2 nas:STAR

• Description:ASTAR(StandardTerminalArrivalRoute)isanairtrafficcontrolcodedarrivalrouteestablishedforapplicationtoarrivingIFR(InstrumentFlightRules)aircraftdestinedforcertainairports.

• Superclasses:o nas:SIDSTAR

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3.10.3 atm:SIDSTARtraverse

• Description:AroutethroughaSID(StandardInstrumentDepartureroute)oraSTAR(StandardArrivalRoute),traversingthecommonrouteatminimumandoptionallyatransitionrouteand/oranairportroute.(Seenas:SIDSTARroute.)

• Superclasses:o atm:NavigationElement

• Objectproperties:o atm:traversesSIDSTAR[nas:SIDSSTAR]:LinksaSIDSTARtraverse(i.e.,aspecificroutethrougha

SIDorSTAR)tothespecificSIDorSTARbeingtraversedbyagivenflight.o atm:usesAirportRoute[nas:AirportRoute]:LinksaSIDSTARtraverse(apaththroughaSID/STAR)

totheairportrouteusedinmakingthetraverse.o atm:usesTransitionRoute[nas:TransitionRoute]:LinksaSIDSTARtraverse(apaththrougha

SID/STAR)tothetransitionrouteusedinmakingthetraverse.


Figure2:StructureofanActualFlightRoute(FlightTrajectory).ThisfigureillustrateshowtheactualandplannedflightroutesforFlight#AAL335areconnectedtotheflightinstance(atm:AAL335-201407150017),whichisdepictedattherootofthetreestructureshown.Theactualflightrouteisrepresentedasasequenceoftrackpoints(atm:AircraftTrackPoint).Eachtrackpointrepresentsaspecificreportingtimewhentheaircraft’sfixandspeediscapturedandrelayedtogroundsystems.Thetrackpointsareeachlinkedtoaninstanceofatm:LatLonFix,whichstoresthelatitude,longitude,andaltitude.ThestructureoftheplannedflightrouteisshowninFigure3.Forasummaryoftheoverallrepresentationofaflight,seeFigure10.

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Figure3:StructureofaPlannedFlightRoute(FlightPlan).Thisillustrationshowstherepresentationforaflightplanwiththeflightroutestring‘KLGA./.CFB..RAAKK.Q436.EMMMA.WYNDE5.KORD’.Theflightroutestringisinitiallyfiledbythepilotpriortotakeoffandmodifiedasneededenroute.Therootnode(atm:PlannedRouteAAL335-201407150017)containsthisroutestringasaproperty.Theroutenodeislinkedtoasequenceof‘container’nodesthat,inturn,point(viaatm:hasNavElement)tothemajornavigationalcomponentsthroughwhichtheflightisplannedtoprogress:theoriginatingairport(KLGA);aVORfix(CFB);aportionofahigh-altitudeflightroute(Q436);atraversethroughastandardterminalarrivalroute(STARWYNDE5);andthedestinationairport(KORD).Theroutestringinthisexampleistruncated,andomitssomecomponentsearlyintheflightplansequence;thegapinthesequencerepresentedbythe‘./.’intheroutestring.Thepositionallocationsofanygapsinthesequenceareencodedintherootnodeasthepropertyatm:planGapAfterSequenceElementNumber.TherepresentationoftheQ436subrouteandthetraverseoftheWYNDE5STARisfurtherelaboratedinFigure4andFigure5,respectively.

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Figure4:PortionofRouteQ436.Thisfigureillustrateshowtheontologyrepresentsaportionofapredefinedsequence(i.e.,asubsequence).Inthiscase,thesequenceisthehigh-altitudeflightroutenamedQ436.Q436isdefinedbytheFAAasapredeterminedsequenceof16navigationalfixes.Inthiscase,onlyaportionoftherouteistobefollowed,asspecifiedintheflightplandescribedinFigure3inthenodelabellednas:AAL355-201407150017_Q436.Therootofthisstructureindicatesthatthesubsequencestartsatposition7intheQ436sequenceandendsatposition2.LiketheflightplaninFigure3,theflightrouteitselfisrepresentedasasequenceof‘containers’thatinturnlinktothenavigationalfixesdefinedfortheroute.Notethatnodesandlinksareomittedfromthisfiguretoreduceclutter.

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Figure5:TraverseofSTARWYNDE5.ThisfigureillustratesaportionoftheflightplaninFigure3thatspecifieshowtheaircraftwilltraversethroughtheWYNDE5STAR.ASTARisdefinedbyasetofdifferentflightpathsandtheflightplanspecifieswhichofthepathswillbetraversedonthisapproachintothedestinationairspace.Inthiscase,theflightwillfollowtheWYNDE5transitionroutenamedEMMA,whichmergesontotheWYNDE5commonroute.Boththetransitionrouteandcommonroutearerepresentedassequencesofnavigationelementcontainers,whereeachcontainerpointstoanavigationfix.ThisisidenticaltotherepresentationforrouteQ436inFigure4.

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4 TrafficManagementInitiatives

TheclassesinthissectiondefineconceptsrelevanttotherepresentationofTrafficManagementInitiatives(TMIs).EachTMIimplementsadifferentkindofrestrictiontoaircraftflow,butsomeaspectsarecommonacrossallTMIs.AllTMIsexpressasetofconditionsunderwhichtheTMIisvalid,andasetofconstraintsonaircraft,airports,and/orairspacefacilitiestowhichtheTMIapplies.AnattempthasbeenmadetousethesameunderpinningsetofclassesacrossallTMIswherepossible,usingabstract,reusableclassestodescribetheseconstraintsonflights,airports,andFAAfacilities.

4.1 atm:TrafficManagementInitiative

• Description:ATrafficManagementInitiative(TMI)isanorchestratedairtrafficmanagementprocedureimplementedbytheFAAsystemcommandcenter(ATCSCC)asneededtocontroltheflowofairtrafficintheNASbasedoncapacityanddemand.AllTMIshavethesamebasicpropertiesincommon;propertiesmorespecifictothetypeofTMIaredefinedinthevarioussubclasses.Notethatbothatm:GroundDelayTMIandatm:GroundStopTMIarelinkedtoaclasscalledatm:DelayModel.ThisclassstorestheparametersassociatedwiththecomputationaldelaymodelusedindeterminingandassigningdelaytimestotheaircraftinvolvedintheGDP(grounddelay)orGS(groundstop).Theclassesatm:AirportSpecandatm:FlightSpecareusedtoconstrainthesetairportsorflightstowhichagivenTMIpertains.Theclassatm:RerouteSegmentlinksarerouteTMIwiththesetofrerouteflightpathsthatareauthorizedforthisreroute.

• Subclasses:o atm:AirspaceFlowProgramTMIo atm:GroundDelayProgramTMIo atm:GroundStopTMIo atm:MilesInTrailTMIo atm:ReRouteTMI

• Objectproperties:o atm:controlledNASelement[atm:TFMcontrolElement]:TheATMelementbeingcontrolledbythe

TMI(theairports,sectors,ARTCCtiers,routes,etc.).Thiselementisspecifiedinthetrafficmanagementadvisorydirective.

o atm:effectiveEndDay[nas:NASday]:TheNASdaytheTMIwasterminated.o atm:effectiveStartDay[nas:NASday]:TheNASdaytheTMIcommenced.o atm:issuedDay[nas:NASday]:TheTMIdateofissuance.

• Datatypeproperties:o atm:advisoryNumber[integer]:AdvisorynumberasreportedfromtheFAACommandCenter

database.Thenumberrestartsat001oneverynewdayUTC.o atm:effectiveEndTime[dateTime]:TheexpectedUTCendtimeofthetrafficmanagement

initiative(TMI).o atm:effectiveStartTime[dateTime]:TheexpectedUTCstarttimeofthetrafficmanagement

initiative(TMI).o atm:extensionProbability[string:“LOW”,“MEDIUM”,“HIGH”]:Theprobabilitythatthistraffic

managementinitiative(TMI)willbeextended.o atm:initiativeComments[string]:Providesanyspecificcommentsonthetrafficmanagement

initiative(TMI)madebytheissuingauthority(e.g.,ATCSCC,ARTCC).

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o atm:issuedTime[dateTime]: Thetimewhenthetrafficmanagementinitiative(TMI)wasissued.

4.1.1 atm:AirspaceFlowProgramTMI

• Definition:AsubclassofTrafficManagementInitiativeinvolvingcontrolandmeteringofairtrafficthroughspecifiedairspacevolumes.

• Superclasses:o atm:TrafficManagementInitiative

• Note:Thisisaplaceholder.AFPswerenotmodeledinanydetail.

4.1.2 atm:GroundDelayProgramTMI

• Definition:AGroundDelayProgram(GDP)trafficmanagementinitiative(TMI).AGDPisatrafficmanagementprocedurewhereaircraftaredelayedattheirdepartureairportinordertomanagedemandandcapacityattheirarrivalairport.


• Objectproperties:o atm:departureScope[atm:AirportSpec]:Linkstothespecificationofthedepartureairport(s)

involvedintheGDPTMI.o atm:flightInclusionSpec[atm:FlightSpec]:Linkstoaspecificationofthesetofflightsthatare

includedintheGDPrestrictions.o atm:flightExclusionSpec[atm:FlightSpec]:Linkstoaspecificationofthesetofflightsthatare

excludedfromtheGDPrestrictions.o atm:modeledBy[atm:DelayModel]:Linkstoarepresentationofthemodelusedtodesignthe

GDP.Themodelcontainsallrelevantparametersusedtocreatetheinitiative.• Datatypeproperties:

o atm:impactingCondition[string:"weather","volume","runway","equipment","other"]:IndicatesthereasonforinitiatingtheGroundDelayProgram.

o atm:impactingConditionMessage[string]:Afree-textdescriptionelaboratingonthereasonforinitiatingtheGroundDelayProgram.

4.1.3 atm:GroundStopTMI

• Definition:AGroundStop(GS)trafficmanagementinitiative(TMI).Agroundstopisaprocedurerequiringaircraftthatmeetspecificcriteriatoremainontheground.TheGSmaybeairportspecific,relatedtoageographicalarea,orequipmentrelated.


• Objectproperties:o atm:departureScope[atm:AirportSpec]:Linkstothespecificationofthedepartureairport(s)

involvedinagroundstopTMI.TrafficboundforthedestinationairportthattheGSisintendedtocontrolisdisallowed.

o atm:flightInclusionSpec[atm:FlightSpec]:LinkstoaspecificationofthesetofflightsthatareincludedintheGSrestrictions.

o atm:modeledBy[atm:DelayModel]:LinkstoarepresentationofthemodelusedtodesigntheGS.Themodelcontainsallrelevantparametersusedtocreatetheinitiative.

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4.1.4 atm:MilesInTrailTMI

• Definition:AMiles-in-Trail(MIT)trafficmanagementinitiative(TMI)isusedtoapportiontrafficintoamanageableflow,aswellasprovidespaceforadditionaltraffic(mergingordeparting)toentertheflowoftraffic.Miles-in-traildescribesthenumberofmilesrequiredbetweenaircraftdepartinganairport,overafix,atanaltitude,throughasector,oronaspecificroute.

• Note:Thisisaplaceholder.MITswerenotmodeledinanydetail.• Superclasses:

o atm:TrafficManagementInitiative

4.1.5 atm:ReRouteTMI

• Definition:AReRouteisatrafficmanagementinitiative(TMI)thatmandatesachangeinthefiledflightplanforasetofspecifiedflights.Therearemultiplefactorsthatmightjustifyareroute,includingweather,trafficcongestion,unusualairspaceactivity,etc.Thesubstituteflightplansrerouteairtrafficaroundtheairspaceproblemarea.


• Objectproperties:o atm:allowedRoute[atm:RerouteSegment]:LinkstoanapprovedroutebetweentheReRoute’s

originanddestination.MultipleapprovedroutesaretypicallyspecifiedinaReRouteTMI.o atm:flightInclusionExclusion[atm:FlightSpec]:LinksaReRoutetoaspecificationoftheflight(s)

includedinorexcludedfromtheReRoutetrafficmanagementinitiative.• Datatypeproperties:

o atm:implementationStatus[string:"FYI","PLN","RMD","RQD"]:IndicatestheenforcementstatusoftheReRouteadvisory:RQD(required),RMD(recommended),PLN(plannedforimplementation),FYI(informationalonly).

o atm:reRouteReason[string:"WEATHER","VOLUME","EQUIPMENT","RUNWAY/TAXIWAY","OTHER"]:ProvidesthereasonforinitiatingaReRoute.

o atm:reRouteTimeType[string:"ETD","ETA","FCAFlightList]:ThetimeperiodassociatedwiththeReRouteisspecifiedinoneofthreeways.TheReRoutecanapplytoflightsthat:departspecifiedairportsorcentersduringacertaintimewindow(timeType=ETD);departspecifiedairportsorcenterstoarriveattheirdestinationsduringacertaintimewindow(timeType=ETA);orarriveattheboundaryofaflowcontrolledarea(FCA)duringacertaintimewindow(timeType=FCAFlightList).

o atm:reRouteType[string:"ROUTE","PLAYBOOK","CDR","SPECIALOPERATIONS","NRPSUSPENSIONS","VS","NAT","SHUTTLEACTIVITY","FCA","FEA","INFORMATIONAL","MISCELLANEOUS"]:TheReRoutetypeencodesinformationaboutthetypeofReRoutebeinginitiatedorthereasonfortheReRoute.

4.2 atm:TFMcontrolElement

• Description:Thisclassrepresentsthediversesetofelementsthatcanbecontrolled/managedbyissuingaTrafficManagementInitiative

• Subclasses:o atm:NavigationElement

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o nas:AirspaceInfrastructureComponent• Datatypeproperties:

o atm:maxFlowCapacity[float]:Theabsolutemaximumcontrollablenumberofaircraftflowingthroughanairspacecontrolelementpersomeintervaloftimeunderidealairtrafficconditions.

4.3 atm:AirportSpec

• Description:Thisclassrepresentsageneralizedspecificationfordefiningasetofairports.Theclasscanbeused,forexample,inthedefinitionofatrafficmanagementinitiativethatisapplicableonlytoaspecifiedsetofairports.Theairportsetcoveredbythespecificationisdeterminedbasedontheinclusionorexclusionofairportsaccordingtothevariouspropertiesofatm:AirportSpeclistedbelow.

• Objectproperties:o atm:excludesARTCC[nas:ARTCCornas:ARTCCtier]:anyairportnotlocatedwithinthe

geographicalborderofanARTCCorARTCCtierlinkedviathispropertyisincludedintheairportset

o atm:excludesAirport[nas:Airport]:anyairportlinkedviathispropertyisnotincludedintheairportset

o atm:includesAirport[nas:Airport]:anyairportlinkedviathispropertyisincludedintheairportset

o atm:withinARTCC[nas:ARTCCornas:ARTCCtier]:anyairportlocatedwithinthegeographicalborderofanARTCCorARTCCtierlinkedviathispropertyisincludedintheairportset

o atm:withinAirportBoundingRegion[gen:CircularRegion]:anyairportlocatedwithinthegeographicalborderofadefinedcircularregionlinkedviathispropertyisincludedintheairportset

• Datatypeproperties:o atm:includesAirportType[string:"all","US","CONUS","NonCONUS","International","Canadian"]:

allairportsofthespecifiedtypeareincludedintheairportset

4.4 atm:FlightSpec

• Description:Thisclassrepresentsageneralizedspecificationfordefiningasetofflights.Theclasscanbeused,forexample,inthedefinitionofatrafficmanagementinitiative(suchasaReRoute)thatisonlyapplicabletoaspecifiedsetofflights.Theflightsetcoveredbythespecificationiscalculatedbasedontheinclusionorexclusionofflightsdefinedbycombiningthepropertiesofatm:FlightSpeclistedbelow.

• Objectproperties:o atm:excludesAirway[nas:AirspaceRoute]:anyflightthatisplannedtooperatealongaroute

linkedbythispropertyisexcludedfromtheflightseto atm:excludesFix[atm:NavigationFix]:anyflightthatisplannedtooperatethroughafixlinkedby

thispropertyisexcludedfromtheflightseto atm:excludesFlight[atm:Flight]:anyflightlinkedbythispropertyisexcludedfromtheflightseto atm:exemptedAFP[atm:AirspaceFlowProgramTMI]:anyflightthatisincludedinanairspaceflow

programlinkedbythispropertyisexcludedfromtheflightseto atm:includesAirway[nas:AirspaceRoute]:anyflightthatisplannedtooperatealongaroute

linkedbythispropertyisincludedintheflightset

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o atm:includesFix[atm:NavigationFix]:anyflightthatisplannedtooperatethroughafixlinkedbythispropertyisincludedintheflightset

o atm:includesFlight[atm:Flight]:anyflightlinkedbythispropertyisincludedintheflightseto atm:mustHaveDestination[atm:AirportSpec]:anyflightwhosedestinationairportislinkedvia

thispropertyisincludedintheflightseto atm:mustHaveOrigin[atm:AirportSpec]:anyflightwhoseoriginairportislinkedviathisproperty

isincludedintheflightseto atm:operatingCarrier[nas:AirCarrier]:anyflightoperatedbyacarrierlinkedviathispropertyis

includedintheflightseto atm:operatingTimeInterval[gen:TimeInterval]:anyflightplannedtoarrive(ETA)–or

alternativelydepart(ETD)–duringthetimeintervallinkedviathispropertyisincludedintheflightset.ThespecificationofETAorETDismadeinthepropertyatm:timeConstraintType

• Datatypeproperties:o atm:includesAircraftClass[string:"Jet","Prop","JetandProp","Turbo","All"]:anyflightflown

usingaircraftcategorizedinthespecifiedclassisincludedintheflightseto atm:aircraftWeightCat[string:"large","heavy","small"]:anyflightoperatedusinganaircraft

withaweightinthespecifiedcategoryisincludedintheflightseto atm:userCategory[string:"GA","AirTaxi","Cargo","Commercial","Military"]:anyflightthatis

classifiedasbelongingtothespecifiedcategoryisincludedintheflightseto atm:timeConstraintType[string:"ETA"or"ETD"]:thispropertyisusedinconjunctionwith

specifyingatm:operatingTimeInterval

4.5 atm:RerouteSegment

• Description:AreroutetrafficmanagementinitiativeprovidesFAA-approvedalternativeroutingsemanatingfromanorigin,convergingtoadestination,orspanningtheentirepathbetweenoriginanddestination.Eachinstanceoftheclassatm:RerouteSegmentspecifiesonethesealternativeroutingsusingthedefinedpropertiesofatm:RerouteSegment.

• Objectproperties:o atm:reRouteConstraint[atm:FlightSpec]:linkstotheflightspecificationthatdetermineswhich

flightsmustusethisroutingo atm:reRoutePath[atm:PlannedFlightRoute]:linkstotheapprovedflightrouteforflights

satisfyingtheflightspecification• Datatypeproperties:

o atm:reRouteSegmentType[string:"origin","destination","origin-destination"]:specifiesthetypeofthereroutesegment,indicatingwhetherthereRoutepathappliestotheorigin,destination,orentireportionoftheflight.

4.6 atm:DelayModel

• Description:ThisclassrepresentsacomputationaldelaymodelusedinassigningtimestotheaircraftinvolvedintheGDPorGS.Thepropertiesofthisclasscorrespondtoparametersthatareusedbythedelaymodeltocomputethedelaytimes.

• Objectproperties:

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o atm:adlDay[nas:NASday]:LinksadelaymodeltothedaythattheADL(AggregateDemandList)wasgenerated.EachADLcontainsinformationontheflightsarrivinganddepartingfromanairport,orenteringintoanddepartingfromaflowarea.

o atm:modeledArrivalRate[atm:ProgramArrivalRateSequence]:LinksadelaymodelusedindefiningaGroundDelayProgram(GDP)orGroundStop(GS)toasequenceofdesiredhourlyaircraftarrivalratesspecifiedfortheinitiative.

o atm:modeledPopUpFactor[atm:PopupFactorSequence]:LinksadelaymodelusedindefiningaGroundDelayProgram(GDP)orGroundStop(GS)toasequenceofdesiredhourlypopupfactorsspecifiedfortheinitiative.'Popups'accountforlate-filingflights(unexpected/unplannedflights)whenmodelingdelaysaspartofatrafficmanagementinitiative(TMI)designprocess.

• Datatypeproperties:o atm:adlTime[dateTime]:ThetimestampoftheADL(AggregateDemandList)thatthedelay

modelisbasedupon.EachADLcontainsinformationontheflightsarrivinganddepartingfromanairport,orenteringintoanddepartingfromaflowarea.

o atm:delayAssignmentMode[string:"DAS","GAAP","UDP"]:Thetypeofdelayassignmentmodespecifiedforthisdelaymodel:DelayAssignment(DAS),GeneralAviationAirportProgram(GAAP),orUnifiedDelayProgram(UDP).

o atm:modeledAverageDelay[integer]:TheaverageflightdelayspecifiedwhenmodelingaGroundDelayProgram(GDP)orGroundStop(GS).

o atm:modeledMaximumDelay[integer]:ThemaximumflightdelayspecifiedwhenmodelingaGroundDelayProgram(GDP)orGroundStop(GS).

o atm:modeledTotalDelay[integer]:ThetotalflightdelayspecifiedwhenmodelingaGroundDelayProgram(GDP)orGroundStop(GS).

o atm:PrevAverageDelay[integer]:TheaverageflightdelayexperiencedpriortothestartofaGroundStop(GS).

o atm:PrevMaximumDelay[integer]:ThemaximumflightdelayexperiencedpriortothestartofaGroundStop(GS).

o atm:prevTotalDelay[integer]:ThetotalflightdelayexperiencedpriortothestartofaGroundStop(GS).

4.7 gen:NumericParameter

• Description:Aclassrepresentingnumericparametersexplicitlyasobjects(versusrepresentingthemasdatatypeproperties).Theseparameterscanbeinsertedintocontainersandsequenced.Thisenablesreuseofthesameparametervalueinmultiplesequences.

• Subclasses:o gen:FloatParametero gen:IntegerParameter

• Datatypeproperties:o gen:parameterValue[untyped]:Thenumericvalueoftheparameter.

4.7.1 gen:FloatParameter

• Description:AsubclassofNumericParameterrepresentingparameterswithfloating-pointvalues.(Note:gen:parameterValueisrestrictedbythisclasstofloatonlyusingOWLrestrictions.)

• Superclasses:

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o gen:NumericParameter

4.7.2 gen:IntegerParameter

• Description:AsubclassofNumericParameterrepresentingparameterswithintegervalues.(Note:gen:parameterValueisrestrictedbythisclasstointegeronlyusingOWLrestrictions.)

• Superclasses:o gen:NumericParameter

• Subclasses:o atm:PopupFactoro atm:ProgramArrivalRate

4.7.2.1 atm:PopupFactor

• Description:Factortoaccountforlate-filingflightswhenmodelingdelaysaspartofatrafficmanagementinitiative(TMI)designprocess.Thisisthenumberofunanticipatedlate-filingflightsperhour.

• Superclasses:o gen:IntegerParameter

4.7.2.2 atm:ProgramArrivalRate

• Description:ThenumberofaircraftthattheGroundDelayProgram(GDP)isintendedtoprovideinboundintotheairportforagivenhour.

• Superclasses:o gen:IntegerParameter

4.8 atm:NumericParameterContainer

• Description:Awrapperaroundanumericparameter.Containerscanbesequencedtocreateanorderedlistofnumericparameters.


• Subclasses:o atm:PopupFactorContainero atm:ProgramArrivalRateContainer

4.8.1 atm:PopupFactorContainer

• Description:Awrapperaroundapopupfactorparameter.UsedtosequencepopupfactorsinthespecificationofaGroundDelayProgram(GDP).

• Superclasses:o atm:NumericParameterContainer

4.8.2 atm:ProgramArrivalRateContainer

• Description:Awrapperaroundaprogramarrivalrate,usedtosequencethemintoanorderedlist.• Superclasses:

o atm:NumericParameterContainer

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4.9 atm:PopupFactorSequence

• Description:ThisorderedsequencecontainstheanticipatedhourlypopupfactorforeachhourastheGroundDelayProgram(GDP)progressesthroughitsperiodofimplementation.

4.10 atm:ProgramArrivalRateSequence

• Description:ThisorderedsequencecontainstheplannedprogramarrivalratesforeachhourastheGroundDelayProgram(GDP)progressesthroughitsperiodofimplementation.


Figure6:GroundStop.ThisfigureillustratestherepresentationforaGroundStopTMIimplementedforflightsboundforKLGAon7/27/14at23:27UTC.ThedeparturescopespecifiestheairportsandCentersfromwhichtrafficboundforKLGAisdisallowed.Thedelaymodellinkedbyatm:modeledByindicatestheprojectedaverage,maximum,andtotaldelayifthegroundstopisimplemented.

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Figure7:GroundDelayProgram.ThisfigurehasthesamestructureasFigure6,butillustrateshowtheprojectedhourlyProgramArrivalRates(PARs)aremodeledasasequenceofcontainersthatpointtoprogramarrivalratevalues.(ThePARrepresentsthenumberofdesirednumberofaircraftinboundtoacontrolledairportinanhour.)Inthiscase,thefirsthourisprojectedtohaveaPARof38,thesecondandthirdhourshaveaPARof40,andthefourthhourhasaPARof42.Notethatinthisfigure,thedeparturescopeairportsandCentersarenotfullyrepresentedtoavoidcluttering.

Figure8:ReRouteTMI.ThisfigureillustratestheontologystructurefortheReRouteTMIshowninFigure9.(Notehoweverthatnodesareomittedtomakethegraphreadable.)SomeoftheroutealternativesspecifiedforthisTMIarelinkedtothemainReRouteTMInodeviatheatm:allowedRoutelink.Eachroutealterativeincludesaroute(linkedviaatm:reRoutePath)andasetofconstraintsunderwhichtherouteisappropriate(linkedviaatm:reRouteConstraint).Inthisexample,thefirstroutealternativeisaroutethatfollowstheflightpathdesignatedbytheflightroutestring‘FNTWYNDE5’,whichcorrespondsto

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flyingtheFNTtransitionrouteintotheWYNDE5STARonarrivalintoKORD.ThatroutingisallowedundertheconstraintthattheflightoriginmustbeKORD,andthedestinationmustbeanairportwithintheClevelandARTCC(ZOBCenter).Asidefromconstraintsonwhenthespecificroutealternativesarepermitted,therearealsooverallconstraintsontheReRouteTMI,linkedwiththepropertyatm:flightInclusionExclusion.Inthiscase,theTMIappliestoanyflightthatoriginatesfromanyoneofasetofspecifiedairportsandisdestinedforKORD.

Figure9:ReRouteTMIAdvisory#013on07/01/2014.Thisisascreenshotfromthefly.faa.govwebsite,whichpublishesFAAadvisories,includingTMIs.TheontologyrepresentationforthisadvisoryisdiscussedinFigure8.

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5 Operations:Flight,Carrier,andAircraft

Theclassesinthissectionpertainthedefinitionandoperationofaflight,extendingtoboththeoperatorandtheaircraft,includingitsmake,model,andmanufacturer.

5.1 atm:Flight

• Description:Asingleflightsegmentfromorigintodestination.• Objectproperties:

o atm:actualArrivalDay[nas:NASday]:Linksaflightwiththedayonwhichtheflightarrives.Thisisthedaydeterminedbysurveillancedatasourcestobethe'actual'dayofarrival,versusthescheduleddayorthedayspecifiedintheflightplan,etc.

o atm:actualDepartureDay[nas:NASday]:Linksaflightwiththedayonwhichtheflightdeparts.Thisisthedaydeterminedbysurveillancedatasourcestobethe'actual'dayofdeparture,versusthescheduleddayorthedayspecifiedintheflightplan,etc.

o atm:aircraftFlown[eqp:Aircraft]:Linksaflightwiththeactualaircraftused.o atm:aircraftTypeFlown[eqp:AircraftType]:Linksaflightwiththetypeofaircraftflown.The

aircraft'type'correspondstoasetofaircraftmodelswithsimilarcharacteristics.o atm:alternateArrivalAirport[nas:Airport]:Linkstothealternatearrivalairporttobeusedincase

ofweather,traffic,orotherunforseencontingency.Thealternateairportisspecifiedintheflightplan.

o atm:arrivalAirport[nas:Airport]:Linkstotheactualarrivalairportfortheflight.Thisistheairportdeterminedbysurveillancedatasourcestobethe'actual'arrivalairport,versusthescheduledairportortheairportspecifiedintheflightplan,etc.

o atm:arrivalRunway[nas:OperationalRunway]:Linkstotheactualarrivalrunwayfortheflight.o atm:arrivalTaxiPath[atm:Taxipath]:Linkstothetaxipathfollowedbytheflightenroutetothe

gate.o atm:departureAirport[atm:Airport]:Linkstotheactualdepartureairportfortheflight.Thisisthe

airportdeterminedbysurveillancedatasourcestobethe'actual'departureairport,versusthescheduledairportortheairportspecifiedintheflightplan,etc.

o atm:departureRunway[nas:OperationalRunway]:Linkstotheactualarrivalairportfortheflight.o atm:departureTaxiPath[atm:Taxipath]:Linkstothetaxipathfollowedbytheflightenrouteto

therunway.o atm:hasActualRoute[atm:ActualFlightRoute]:Linksaflighttoitsactualtrajectory(i.e.,a

sequenceoftrackpoints),asdeterminedbyflighttracksurveillancedata.o atm:hasCrewMember[atm:CrewMember]:Linksaflighttoitscrewmembers.o atm:hasPlannedRoute[atm:PlannedFlightRoute]:Linksaflighttoaversionofitsflightplan.

(Whichversiongetsstoredisapplication-dependent.)Therearemultipleversionsoftheflightplangeneratedandthenamendedduringthecourseoftheflight,startinginthepre-flighttimeframeandextendingthroughtotheterminationoftheflight.

o atm:operatedBy[nas:AirCarrier]:Linksaflighttoitscarrierairline.o atm:plannedArrivalDay[nas:NASday]: Linkstothedaythattheflightisplannedtoarriveperthe

initialfiledflightplan.o atm:plannedDepartureDay[nas:NASday]:Linkstothedaythattheflightisplannedtodepartper

theinitialfiledflightplan.

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o atm:publishedArrivalDay[nas:NASday]:LinkstothedaythattheflightisplannedtoarrivepertheOAGschedule.

o atm:publishedDepartureDay[nas:NASday]:LinkstothedaythattheflightisplannedtodepartpertheOAGschedule.

• Datatypeproperties:o atm:actualArrivalTime[dateTime]:Thetimedeterminedbysurveillancedatasourcestobethe

'actual'timeofflightarrival,versusthescheduledtimeorthetimespecifiedintheflightplan,etc.

o atm:actualDepartureTime[dateTime]:Thetimedeterminedbysurveillancedatasourcestobethe'actual'timeofflightdeparture,versusthescheduledtimeorthetimespecifiedintheflightplan,etc.

o atm:adsbID[string]:TheuniqueidentifieroftheADS-B(AutomaticDependentSurveillance-Broadcast)transponderunitonboardtheaircraftforthisflight.

o atm:callSign[string]:Theflightidentifier(3-letterICAOcodeplusnumber).o atm:cruisingAltitude[integer]:Thecruisingaltitude(innumberoffeet)specifiedintheinitial

filedflightplanforthisflight.o atm:fixTrajectoryString[string]:Thisisanexperimentalpropertyofaflightthatstoresanordered

sequenceofnamedfixescorrespondingone-to-onetothesequenceoftrajectorytrackpointsrecordedfortheflight.Foragiventrackpoint,thecorrespondingnamedfixiscomputedbyfindingtheclosestnamedfixtothetrackpoint.

o atm:plannedArrivalTime[dateTime]:Thetimethattheflightisplannedtoarrivepertheinitialfiledflightplan.

o atm:plannedDepartureTime[dateTime]:Thetimethattheflightisplannedtodepartpertheinitialfiledflightplan.

o atm:publishedArrivalTime[dateTime]:ThetimethattheflightisplannedtoarrivepertheOAGschedule.

o atm:publishedDepartureTime[dateTime]:ThetimethattheflightisplannedtodepartpertheOAGschedule.

o atm:traconID[string]:ThreeletterFAATRACONidentifiercode.o atm:trueAirspeed[integer]:Thetrueairspeedofaflight:thespeedoftheaircraftrelativetothe

airmassinwhichitisflying.o atm:userCategory[string:"GA","AirTaxi","Cargo","Commercial","Military"]:Thetypeof

airspaceuserthatthisflightrepresents.Thispropertycanbeusedtoconstrainaflightspecification(atm:FlightSpec)tocontainonlyflightsrepresentingaspecificusercategory.

5.2 atm:CrewMember

• Description:Thesetofinflightairlinepersonneloperatingorperformingservicingfunctionsonaflight(pilotsandcabinattendants).Note:thisisaplaceholderclassandhasnotbeenmodeledinanydetail.

5.3 eqp:AviationServiceProvider

• Description:Asuperclassencompassingallentitiesthatprovideaviationservicesinthepublicandprivatesectors.

• Subclasses:o nas:AirCarrier

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o nas:AviationIndustryManufacturero nas:GovernmentAviationServiceProvider

5.3.1 nas:AirCarrier

• Description:Acommercialentitythatislicensedtooperateaircraft.Theinstancesofthisclasswerederivedfromthelistpublishedathttp://openflights.org/data.html#airline.

• Superclasses:o nas:AviationServiceProvider

5.3.2 nas:AviationIndustryManufacturer

• Description:Asuperclassencompassingthesetofairframeandenginemanufacturers.• Superclasses:

o nas:AviationServiceProvider• Subclasses:

o nas:AirframeManufacturero nas:AircraftEngineManufacturer

5.3.2.1 nas:AirframeManufacturer

• Description:Amanufacturerofaircraft.• Note:TheinstancesofthisclasswerederivedfromtheIACIS(InternationalAircraftCategorizationAnd

IdentificationStandard)AircraftTaxonomyproducedbytheCAST/ICAOCommonTaxonomyTeam(http://www.intlaviationstandards.org).

• Superclasses:nas:AviationIndustryManufacturer

5.3.2.2 nas:AircraftEngineManufacturer

• Description:Amanufacturerofaircraftengines.• Superclasses:nas:AviationIndustryManufacturer

5.3.3 nas:GovernmentAviationServiceProvider

• Description:Asuperclassencompassingthesetofairframeandenginemanufacturers.• Superclasses:

o nas:AviationServiceProvider

5.4 eqp:EngineeredSystem

• Description:Representsengineeredsystemsaseitherdecomposableornon-decomposablesubsystems.• Subclasses:

o eqp:DecomposableSystemo eqp:UnitAssembly

• Objectproperties:o eqp:manufacturedBy[nas:AviationIndustryManufacturer]:Linkstothemanufacturerofthe

engineeredsystem.• Datatypeproperties:

o eqp:manufactureYear[integer]:Yearthatthesystemwasmanufactured.

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o eqp:modelID[string]:Thesystemmodelidentifier.

5.4.1 eqp:DecomposableSystem

• Description:Representsacomplexengineeringsystemthatcanbefurtherdecomposedintoasetofdecomposablesubsystemsandprimitivecomponents.

• Superclasses:o eqp:EngineeredSystem

• Subclasses:o eqp:AircraftSubsystemo eqp:NavigationAido eqp:Aircraft

• Objectproperties:o eqp:hasComponent[eqp:UnitAssembly]:Linkstoanyprimitiveportionofthedecomposable

system.Thiscorrespondstoaunitassemblythatisnotmodeledatafinerlevelofgranularity.o eqp:hasSubsystem[eqp:DecomposableSystem]:Linkstoafurtherdecomposableportionofthe

engineeredsystem.

5.4.1.1 eqp:AircraftSubsystem

• Description:Anengineeringsubsystemofanaircraft.• Superclasses:

o eqp:DecomposableSystem• Subclasses:

o eqp:AircraftCommunicationSystemo eqp:AircraftEngineo eqp:AircraftNavigationSystemo eqp:ElectricalPowerSystem

• Note:Thelistedsubclassesareforillustrationpurposesonlyandhavenotbeenfurthermodeledintheontology

5.4.1.1.1 eqp:AircraftCommunicationsSystem

• Description:Anaircraftsubsysteminvolvingallvoiceanddatacommunicationsfunctions.• Superclasses:

o eqp:AircraftSubsystem

5.4.1.1.2 eqp:AircraftEngine

• Description:Anaircraftengineisthecomponentofthepropulsionsystemforanaircraftthatgeneratesmechanicalpower.

• Superclasses:o eqp:AircraftSubsystem

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5.4.1.1.2.1 eqp:EngineType

• Description:Representsgenerictypesofaircraftengines.Specifictypesarerepresentedasinstancesofthisclass,includingtypesforelectricengine,jetengine,propellerengine,andturbopropengine.Thisclassisusedtomapaircrafttypesintooneoftheseenginetypes.

• Datatypeproperties:o eqp:engineTypeDescription[string]:Atextdescriptionoftheenginetypecharacteristics.

5.4.1.1.3 eqp:AircraftNavigationSystem

• Description:Anaircraftsubsystemresponsiblefornavigationfunctions.• Superclasses:


5.4.1.1.4 eqp:ElectricalPowerSystem

• Description:Anaircraftsubsystemresponsibleforgeneratinganddistributingelectricalpower.• Superclasses:


5.4.1.2 eqp:NavigationAid

• Description:Anavaid(navigationalaid)isanengineeredsystemonthegroundthatairplanescandetectbasedontheiremissionofradiosignalsthatenabletheaircrafttonavigate.ModernexamplesincludeNDBsandVORs,whichbothtransmitradiosignalsthataircraftcanfollowandhomeinon.

• Superclasses:o eqp:DecomposableSystem

• Note:Thisclassisforillustrationpurposesonlyandhasnotbeenmodeledindetailintheontology

5.4.2 eqp:UnitAssembly

• Description:Aprimitive,non-decomposiblecomponentinanengineeredsystem.• Superclasses:

o eqp:EngineeredSystem• Subclasses:

o eqp:BallBearing• Note:Thelistedsubclassesareforillustrationpurposesonlyandhavenotbeenfurthermodeledinthe

ontology

5.4.2.1 eqp:BallBearing

• Description:Aunitassemblyinanaircraftmechanicalsubsystem,aballbearingispositionedbetweenawheelandafixedaxle,inwhichtherotatingpartandthestationarypartareseparatedbyaringofsmallsolidmetalballsthatreducefriction.

• Superclasses:o eqp:UnitAssembly

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5.4.3 eqp:Aircraft

• Description:Thisclassrepresentsthephysicalrealizationofanaircraft,producedbyamanufactureraccordingtothespecificationsdefinedforaspecificmodel.Propertiesofaircraftinstances,suchasserialnumber,registration(tail)number,aircraftregistrant,andothersarederivedfromtheFAA’sAircraftRegistry(https://www.faa.gov/licenses_certificates/aircraft_certification/aircraft_registry/releasable_aircraft_download/).

• Superclasses:o eqp:DecomposableSystemo gen:SequencedItem

• Objectproperties:o eqp:hasAircraftModel[eqp:AircraftModel]:Linkstothemodelforthisaircraft.Themodelisthe

abstractspecificationusedinthemanufactureofthephysicalaircraft.• Datatypeproperties:

o eqp:aircraftModelCertainty[float]:Anumericmeasurebetween0and1reflectinghowcertaintheeqp:hasAircraftModellinkistobecorrectbetweentheaircraftandthemodel.Avalueofoneindicates100%certainty.Alesservalueisnottobetakenasapercentage,butisaheuristicsimilarityvaluetakenfromthescoringoftheTF/IDFsimilarityassessmentperformedbetweentheFAAaircraftmake/modelintheFAAregistrationdatabaseandICAOmake/modelnamesusedintheontology(seeeqp:AircraftModelfordetails).

o eqp:aircraftRegistrant[string]:TheentitythatregisteredtheaircraftwiththeFAA.(Note:Theregistrantisrepresentedasastring,butatsomepointshouldinsteadbelinkedtoanamedbusinessentities.Oftentheentitiesarecarrier,whicharealreadyrepresentedintheontology.)

o eqp:aircraftSerialNumber[string]:Themanufacturerserialnumberoftheaircraft.o eqp:certificateIssueDate[date]:Thedatethattheairworthinesscertificatewasissuedforthe

aircraft.o eqp:modeSCode[string]:TheuniqueModeSaddressofthetransponderaboardtheaircraft.

ModeSequipmentonaircraftareassignedauniqueICAO24-bitaddressor(informally)ModeShexcodeuponnationalregistrationandthisaddressbecomesapartoftheaircraft'sCertificateofRegistration.

o eqp:numberOfEngines[integer]:Thenumberofenginesspecifiedforthisaircraftmodelorfoundonthisaircraft.

o eqp:numberOfSeats[integer]:Thenumberofseatsonthisaircraft.o eqp:registrationNumber[string]:TheaircraftFAAregistrationnumber(thetailnumber,ortheN-

NumberintheUS).

5.4.3.1 eqp:AircraftModel

• Description:Anaircraftmodelrepresentsagenericspecificationdescribingthecharacteristicsofaspecifictypeofaircrafttobemanufactured.Thesubclassesandinstancesbeneatheqp:AircraftModelarederivedfromtheIACIS(InternationalAircraftCategorizationAndIdentificationStandard)AircraftTaxonomyproducedbytheCAST/ICAOCommonTaxonomyTeam(http://www.intlaviationstandards.org).Thesubclassesofeqp:aircraftModelcorrespondtosetsofrelatedaircraftmodels,asdefinedbythe

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taxonomynotionofa‘mastermodel’;instancescorrespondtoanindividual‘make/model/series’inthetaxonomy.

• Objectproperties:o eqp:isAircraftType[eqp:AircraftType]:Linksanaircraftmodeltoitscorrespondingaircrafttype.

(Eachaircrafttypeencompassesasetofrelatedmodels.)o eqp:designedBy[nas:AirframeManufacturer]:Linksanaircraftmodeltotheairframe

manufacturerthatdesignedthemodel.• Datatypeproperties:

o eqp:cicttNumber[integer]:CAST/ICAOCommonTaxonomyTeam(CICTT)identifierforthismodelasspecifiedbytheInternationalAircraftCategorizationAndIdentificationStandard(IACIS).

o eqp:numberOfEngines[integer]:Thenumberofenginesspecifiedforthisaircraftmodelorfoundonthisaircraft.

5.4.3.2 eqp:AircraftType

• Description:Theaircrafttypedesignatorisacodingschemethatspecifiesaircraftmodelswithsimilaroperationalflightcharacteristics.ICAOmaintainsthelistofaircrafttypedesignatorcodes.Eachcodelinkstooneormoreaircraftmodelsusingthemodel’spropertyeqp:isAircraftType.Inaddition,thetypedesignatorislinkedtootherpropertiescommontothesetofaircraftmodelsrepresentedbythetypedesignator.TheaircrafttypedesignatorissimilartotheCAST/ICAOCommonTaxonomy(http://www.intlaviationstandards.org)notionofa‘mastermodel’,exceptanaircrafttypemaycoverabroadersetofaircraftmodelsthana‘mastermodel’.

• Objectproperties:o eqp:hasAircraftEngineType[eqp:EngineType]:linkstothetypeofengineusedbythisaircraft

typeo eqp:hasAircraftWakeCategory[eqp:AircraftWakeCategory]:linkstotheaircraftwakecategory

assignedbyFAAtothistypeofaircrafto eqp:hasAircraftWeightClass[eqp:AircraftWeightClass]:linkstotheweightclassassignedbyFAA

tothistypeofaircraft• Datatypeproperties:

o eqp:aircraftTypeDesignator[string]:Thetypedesignatorcodeforthistypeofaircraft(e.g.,B777).

5.4.3.3 eqp:AircraftWakeCategory

• Description:Acategorydefinedintermsofaircraftwaketurbulancecharacteristics(includingtakeoffweightandwingspan).ThewaketurbulencecategoryisusefulforthepurposeofFAAseparationassurance.SeeFAAOrderJO7110.659B,WakeTurbulenceRecategorization,effectiveMarch01,2015.Thereare8definedcategories,whicharerepresentedasinstancesofthisclass.Thisclassisusedtomapthesetofaircrafttypesintooneofthesecategories.

• Datatypeproperties:o eqp:maxTakeoffWeightHighBound[integer]:Theupperboundofthemaximumtakeoffweight

forthiscategory.o eqp:maxTakeoffWeightLowBound[integer]:Thelowerboundofthemaximumtakeoffweightfor

thiscategory.

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o eqp:wakeCategoryID[string]:Thewakecategoryidentificationcharacter(AthroughF)asdefinedintheFAAOrder.

o eqp:wingSpanHighBound[integer]:Theupperboundofthewingspanforthiscategory.Ifnotspecified,theupperrangeofthewingspanintervalisunbounded.

o eqp:wingSpanLowBound[integer]:Thelowerboundofthewingspanforthiscategory.

5.4.3.4 eqp:AircraftWeightClass

• Description:Acategorydefinedintermsofaspecifiedaircraftweightinterval.Therearethreedefinedcategoriesofaircraftweight(high,medium,low),whicharerepresentedasinstancesofthisclass.Thisclassisusedtomapthesetofaircrafttypesintooneofthesecategories.

• Datatypeproperties:o eqp:aircraftWeightHighBound[integer]:Theupperboundoftheaircraftweightinterval.Ifnot

provided,theupperrangeoftheweightintervalisunbounded.o eqp:aircraftWeightLowBound[integer]:Thelowerboundoftheaircraftweightinterval.


Figure10:StructureofaFlight.Thisfigureillustratesthebasiccomponentsoftheontologyrepresentationofaflight.Eachflightisassociatedwithitsdepartureandarrivalairports;theaircraft,aircrafttype,andoperatingcarrier;andtheactualandplannedflightroute.TherepresentationfortheactualandplannedflightisdescribedinFigure2andFigure3,respectively.

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Figure11:Relationshipsamonginstancesofaircraft,carrier,flight,model,manufacturer,andotherclassesassociatedwithDeltaAirlinesflightDAL435on2014-07-15.TheaircraftflownforthisflightisN713TW,aBoeingmodel757-2Q8,oneoftheB757-200familyofaircraft.Theaircraftfamilyisrepresentedasamodelclassandthethespecificmodelisrepresentedasaninstanceofthatclass.TheFAAalsodesignatesanaircrafttype,whichmaycovermodelsinmultipleaircraftfamilies.Theaircrafttypeformodel757-2Q8isB752.AssociatedwithtypeB752aircraftareasetofinstancesthatdescribetheenginetype,waketurbulencecategory,andweightclassofallB752typeaircraft.

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6 AirportandSurfaceOperations

Theclassesinthissectioncenterondefininganairportanditsphysicalinfrastructure,includingthestructuresinvolvedinsurfacemovementandoperations.

6.1 nas:Airport

• Description:Afacilitywhereaircraftarriveanddepart.• Superclasses:

o atm:NavigationElemento data:METARreportingStationo nas:NASfacility

• Subclasses:o nas:InternationalAirport

§ nas:CanadianAirporto nas:USairport

§ nas:CONUSairport:AirportsinthecontinentalUS§ nas:NonCONUSairport:AirportsoutsidethecontinentalUS

• Note:Theinstancesofthisclasswerederivedfromtwosources:o Fordomesticairports:FAApublisheddata,includingtheATCTowerandSatelliteAirport

Communicationsdatafilefromthe56-DayNASRsubscriptionavailableattheNFDCportal(https://nfdc.faa.gov)

o Forinternationalairports:Alistpublishedbyopenflights.orgathttp://openflights.org/data.html#airport.

• Objectproperties:o data:hasAirportData[data:AirportData]:Linksanairporttoacollectionoftemporally-dependent

datapertinenttotheairportconditions,includingavarietyofdatacollectedintheASPMsystem.o data:hasTAFreport[data:TAFreport]:AssociatesanairportwithTAFweatherreportsgenerated

forthatairport.o nas:airportBoundary[gen:Polygonal2DRegion]:Linksanairporttoarepresentationofitssurface

area,includingitsperimeterboundary.o nas:airportLocation[gen:PointLocation]:Linkstoageographicpointdesignatedastheairport’s

location.o nas:hasRunway[nas:PhysicalRunway]:Linksanairporttothephysicalrunwaysforthatairport.o nas:hasSID[nas:SID]:AssociatesanairportwiththeSIDsdesignatedtorouteaircraftdeparting

fromthatairport.o nas:hasSTAR[nas:STAR]:AssociatesanairportwiththeSTARsdesignatedtorouteaircraft

arrivingatthatairport.o nas:hasTaxiway[nas:Taxiway]:Linksanairporttothetaxiwayscomprisingtheairportsurface

networko nas:hasTerminal[nas:Terminal]:Linksanairporttotheterminal(s)forthatairport.o nas:hasTower[nas:ATCT]:Linksanairporttoanairtrafficcontroltower(s)forthatairport.o nas:withinARTCC[nas:ARTCC]:LinkstheairporttotheARTCCwithinwhichitislocated.

• Datatypeproperties:o nas:airportName[string]:Theofficialnameoftheairport.

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o nas:faaAirportCode[string]:ThealphanumericFAAcodeoflength3or4designatedfortheairport.AscontrastedwiththeICAOandIATAcodes,whichingeneraldifferfromtheFAAcode.Often,however,theIATAandFAAcodesareidentical.

o nas:hoursOffsetFromUTC[integer]:ThenumberofhoursthattheairportisoffsetfromtheUTCtimezone.

o nas:iataAirportCode[string]:Thethree-letterIATAcodeassignedtotheairport.AscontrastedwiththeICAOandFAAairportcodes.

o nas:icaoAirportCode[string]:Thethree-letterICAOcodeassignedtotheairport.AscontrastedwiththeIATAandFAAairportcodes.

o nas:isInstrumentControlEligible[boolean]:Indicateswhetherthisairportiscapableofaninstrumentapproach.

o nas:isWeatherReportingStation[boolean]:IndicateswhetherthisairportisaMETARweatherreportingstation.

o nas:locatedInState[string]:The2-letterUSpostalcodeforthestateinwhichtheairportislocated.

o nas:withinTimezone[string]:Thetimezoneidentifierfortheairport,wherethetimezoneisspecifiedasArea/Location,e.g.‘America/New_York’.

6.1.1 nas:InternationalAirport

• Superclasses:o nas:Airport

• Subclasses:o nas:CanadianAirport

6.1.1.1 nas:CanadianAirport

• Superclasses:o nas:InternationalAirport

6.1.2 nas:USairport

• Superclasses:o nas:Airport

• Subclasses:o nas:CONUSairporto nas:NonCONUSairport

6.1.2.1 nas:CONUSairport

• Superclasses:o nas:USairport

6.1.2.2 nas:NonCONUSairport

• Superclasses:o nas:USairport

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6.2 data:AirportData

• Description:Representsacollectionofairportdataforagiventimeperiod,asreportedbytheFAA'sASPMsystem(http://aspm.faa.gov).


• Objectproperties:o data:hasASPMmetCondition[data:ASPMmeteorologicalCondition]:Linksmeteorological

informationtothecollectionoftemporally-dependentdataassociatedwithanairport.• Datatypeproperties:

o data:airportArrivalRate[integer]:Thearrivalrateperhoursetbytheairportduringthespecifiedinterval.Thisisthetotalnumberofaircraftthatcanarriveonallrunwayscombinedduringanhour.

o data:airportDepartureRate[integer]:Thedeparturerateperhoursetbytheairportduringthespecifiedinterval.Thisisthetotalnumberofaircraftthatcandepartfromallrunwayscombinedduringanhour.

o data:arrivalDemand[integer]:Thenumberofaircraftintendingtoarriveatanairportduringthespecifiedtimeperiod.

o data:aspmFlightRules[string:"I","V"]:Indicateswhatflightruleconditionstheairportisoperatingunderduringthespecifiedtimeperiod(I-instrument,V-Visual).

o data:departureDemand[integer]:Thenumberofaircraftintendingtodepartduringthespecifiedtimeperiod.

o data:edctArrivalHold[float]:EDCT(EstimatedDepartureClearanceTime)holdminutesatotherairportsarrivingthisairport.

o data:edctDepartureHold[float]:EDCT(EstimatedDepartureClearanceTime)holdminutesatotherairportsdepartingthisairport.

o data:etmsArrivals[integer]:CountofarrivalsatairportbasedonETMS(EnhancedTrafficManagementSystem)data.

o data:etmsDepartures[integer]:CountofdeparturesatairportbasedonETMS(EnhancedTrafficManagementSystem)data.

o data:highWindWITIdaily[float]:Thehighwindweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(daily).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandforadefinedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Ifthewindsattheairportareaboveasetthreshold,thenthehighwindWITIissettothenumberofscheduledarrivalsforthattimeframe(daily).

o data:highWindWITIhourly[float]:Thehighwindweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(hourly).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandforadefinedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Ifthewindsattheairportareaboveasetthreshold,thenthehighwindWITIissettothenumberofscheduledarrivalsforthattimeframe(hourly).

o data:lowCeilingWITIdaily[float]:Thelowceilingweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(daily).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandfora

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definedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Iftheceilingattheairportisbelowasetthreshold,thenthelowceilingWITIissettothenumberofscheduledarrivalsforthattimeframe(daily).

o data:lowCeilingWITIhourly[float]:Thehighwindweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(hourly).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandforadefinedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Iftheceilingattheairportisbelowasetthreshold,thenthelowceilingWITIissettothenumberofscheduledarrivalsforthattimeframe(hourly).

o data:lowVisibilityWITIdaily[float]:Thelowvisibilityweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(daily).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandforadefinedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Ifthevisibilityattheairportisbelowasetthreshold,thenthelowvisibilityWITIissettothenumberofscheduledarrivalsforthattimeframe(daily).

o data:lowVisibilityWITIhourly[float]:Thelowvisibilityweatherimpactedtrafficindex(WITI)computedfortheairportduringthespecifiedtimeframe(hourly).WITIisanestimateofthenumberofflightspotentiallyimpactedduetoinclementweatherbasedonthescheduledtrafficdemandforadefinedgeographicregionoftheairtrafficsystem(inthiscase,anairport).Ifthevisibilityattheairportisbelowasetthreshold,thenthelowvisibilityWITIissettothenumberofscheduledarrivalsforthattimeframe(hourly).

o data:oagArrivalDelay[integer]:MinutesofOAG(OfficialAirlineGuide)basedarrivaldelayinexcessof15minutes.

o data:oagGateDepartureDelay[integer]:MinutesofOAG(OfficialAirlineGuide)basedgatedeparturedelayinexcessof15minutes.

o data:scheduledArrivals[integer]:Countofscheduledarrivals.(MostprobablyfromOAG(OfficialAirlineGuide))

o data:scheduledDepartures[integer]:Countofscheduleddepartures.(MostprobablyfromOAG(OfficialAirlineGuide))

o data:totalAirborneDelay[float]:Totalairborneflightdelayinminutesforthisairportduringthespecifiedperiod.

6.2.1 data:WITIproperty

• Description:ApropertyclasscontainingvariousinstancepropertiesrelatingtoWITI(Weather-ImpactedTrafficIndex),includingdata:highWindWITIdaily,data:highWindWITIhourly,data:lowCeilingWITIdaily,data:lowCeilingWITIhourly,data:lowVisibilityWITIdaily,anddata:lowVisibilityWITIhourly.

• Superclasses:o owl:DatatypeProperty

6.3 nas:AirportInfrastructureComponent

• Description:Partofanairport'sphysicalinfrastructure,includinggates,terminals,runways,taxiways,etc.• Subclasses:

o nas:AirportServiceVehicleo nas:ATCT

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o nas:DeicingPado nas:Gateo nas:OperationalRunwayo nas:PhysicalRunwayo nas:RampTowero nas:Taxiwayo nas:Terminal

• Objectproperties:o nas:associatedAirport[nas:Airport]:Linksanairportinfrastructurecomponenttoitsassociated

airport.

6.4 nas:AirportServiceVehicle

• Description:Aclassofvehiclesthatservicetheflightsandmaintaintheairportphysicalinfrastructure.• Subclasses:(Note:thefollowingsubclassesareonlyplaceholders.Nodetailshavebeenmodeled.)

o nas:DeicingTrucko nas:RefuelingTruck

6.4.1 nas:DeicingTruck

• Description:Avehiclethatholdsdeicingfluidandpumpingequipmenttosupportdeicing.• Superclasses:

o nas:AirportServiceVehicle

6.4.2 nas:RefuelingTruck

• Description:Vechiclethattransportsandpumpsjetfueltorefuelaircraft.• Superclasses:

o nas:AirportServiceVehicle

6.5 nas:ATCT

• Description:TheAirTrafficControlTowerfacilityisresponsibleformanagingarrivals,departures,andsurfacemovementofaircraftonrunwaysandtaxiways.

• Superclasses:o nas:AirportInfrastructureComponento nas:NASfacility

• Datatypeproperties:o nas:towerID[string]:TheFAAidentifierforairtrafficcontroltower.

6.6 nas:RampTower

• Description:Acontroltowerfromwhichrampcontrollersguideaircraftmovementsastheyenterandexitthetaxiways,andarriveandleavethegates.Therampistheareaoftheairportsurfacewhereplanes,servicevehicles,andpeoplemeet.Note:Thisclassisonlyaplaceholder;nodetailhasbeenmodelled.

• Superclasses:o nas:AirportInfrastructureComponent

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6.7 nas:DeicingPad

• Description:Aphysicallocationintheairportwheredeicingisperformed.• Superclasses:

o nas:AirportInfrastructureComponent• Objectproperties:

o nas:deicingPadLocation[gen:Polygonal2DRegion]:Linksadeicingpadwithitslocationasatwo-dimensionalregionwithaboundingpolygon.

o nas:hasQueue[nas:DeicingQueue]:Linksadeicingpadtoitsqueueofaircraftwaitingtobedeiced.

6.7.1 nas:DeicingQueue

• Description:Anorderedsequenceofaircraftawaitingdeicingatadeicingpad.• Superclasses:

o gen:Sequence

6.8 nas:Gate

• Description:Aphysicalinterfacebetweentheaircraftandtheterminal,usedtoboardpassengersandcrew.


• Subclasses:Thefullsetofgatesforeachairportisrepresentedasasubclass,andthissubclass,inturn,hasseveralsubclassesbreakingthefullsetintosubsetscorrespondingtothegatesforeachterminal.Theactualinstancesofgatesareassociatedwiththeseterminal-relatedgatesubclasses.Forexample:

o nas:KDFWGate:TheclassofallgatesatKDFW§ nas:KDFWterminalAgate:ThesubclassofgatesatTerminalA.

• nas:KDFWtermAgateA10(instanceofgateatTerminalA)• nas:KDFWtermAgateA11(instanceofgateatTerminalA)• etc.

§ nasKDFWterminalBgate:ThesubclassofgatesatTerminalB.§ etc.

Note:Subclassesandinstanceswerecreatedonlyforfourairports:KDFW,KEWR,KJFK,andKLGA.

• Datatypeproperties:o nas:gateID[string]:Thegateidentifierassignedbytheairportauthority.

6.9 nas:PhysicalRunway

• Description:Aphysicalrunway,definedasadelimitedrectangularsurfaceregionoftheairport.Eachphysicalrunwayisassociatedconceptuallywithtwooperationalrunways,180degreesapart,torepresenttheuseoftherunwaytakingofforlandingineitherdirection.

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• Subclasses:Thereisasubclassofnas:PhysicalRunwaycorrespondingtoeachairport.Eachphysicalrunwayatthedesignatedairportisaninstanceofthisclass.Note:SubclassesandinstanceswerecreatedonlyforUSandselectCanadianairports.

• Objectproperties:o nas:associatedOpRunway[nas:OperationalRunway]:Associatesaphysicalrunwaywithitstwo

operationalrunways(180degreesapart,representingapproachesfromoppositeendsofthephysicalrunway).

o nas:runwayFootprint[gen:Polygonal2DRegion]:Associatesaphysicalrunwaywithitsboundingtwo-dimensionalrectangle.

• Datatypeproperties:o nas:runwayID[string]:Anidentifierfortherunway.Theconventionistolabelrunwaysbytheir

heading,droppingthelastdigit.Foroperationalrunways,therunwayidentifierspecifiesonlyoneheadingcorrespondingtothedirectionoftravelontherunway;forphysicalrunways,therunwayidentifierspecifiesbothheadings(180degreesapart).Forexample,atLiverpoolairport,theoperationalrunwaylabeled‘09’(approximatelymagneticheading90degrees)isdistinctfromtheoperationalrunwayintheoppositedirectionoftravelalongthesamephysicalrunway,whichislabeled‘27’(approximatelymagneticheading270degrees).Theidentifierforthephysicalrunwayis‘09/27’.Ifanairporthasparallelrunways,thesewouldthenbemarkedLeft,CenterandRight,e.g.09L,09C,09R.

o nas:runwayLengthInFeet[float]:Thelengthinfeetofthephysicalrunway.o nas:runwayWidthInFeet[float]:Thewidthinfeetofthephysicalrunway.

6.9.1 data:RunwayStatusData

• Description:Thisclassdescribesatemporally-dependentsetofdataabouttheoperatingstatusofaphysicalrunway.


• Objectproperties:o data:runwayReportedOn[nas:PhysicalRunway]:Associatesarunwaystatusreportwiththe

physicalrunwaybeingmeasured.• Datatypeproperties:

o data:runwayStatus[string:“open”,“closed”]:Anindicatorofwhethertherunwayisopenorclosedduringthespecifiedperiod.

o data:runwaySurfaceFriction[float]:Thesurfacefriction(mu)valueoftherunwayforthespecifiedperiod.Runwaysurfacefrictionisdirectlyrelevanttothebrakingactionwhichwillbeavailabletoanaircraftdeceleratingaftertouchdown,orafteradecisiontorejectatakeoff.

6.10 nas:OperationalRunway

• Description:Anoperationalrunwayisanamedrunwayusedinairportoperations.Therearetwooperationalrunwayscorrespondingtoasingleunderlyingphysicalrunway;theseoperationalrunwaysare

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180degreesapartandarenamedbasedontherunwayheadingasdeterminedbythedirectionofaircrafttravelontherunway.


• Subclasses:Thereisasubclassofnas:OperationalRunwayforeachairport.Eachoperationalrunwayatthedesignatedairportisaninstanceofthisclass.Note:SubclassesandinstanceswerecreatedonlyforUSandselectCanadianairports.

• Objectproperties:o nas:touchdownPoint[gen:PointLocation]:Linkstothegeographicalpointlocationthatisthe

designatedtouchdownspotontheoperationalrunway.• Datatypeproperties:

o nas:runwayID[string]:Anidentifierfortherunway.Theconventionistolabelrunwaysbytheirheading,droppingthelastdigit.Foroperationalrunways,therunwayidentifierspecifiesonlyoneheadingcorrespondingtothedirectionoftravelontherunway;forphysicalrunways,therunwayidentifierspecifiesbothheadings(180degreesapart).Forexample,atLiverpoolairport,theoperationalrunwaylabeled‘09’(approximatelymagneticheading90degrees)isdistinctfromtheoperationalrunwayintheoppositedirectionoftravelalongthesamephysicalrunway,whichislabeled‘27’(approximatelymagneticheading270degrees).Theidentifierforthephysicalrunwayis‘09/27’.Ifanairporthasparallelrunways,thesewouldthenbemarkedLeft,CenterandRight,e.g.09L,09C,09R.

6.11 nas:Taxiway

• Description:Anairportsurfacepathwaythataircrafttraverseintravelingbetweentheramparea(i.e.,theareainthevicinityofthegates)andtherunways.

• Superclasses:o nas:AirportInfrastructureComponento gen:SequencedItem

• Objectproperties:o nas:taxiwayFootprint[gen:Polygonal2DRegion]:Associatesataxiwaywithitsboundingtwo-

dimensionalrectangle.• Datatypeproperties:

o nas:taxiwayID[string]:Theairportauthority’sofficialidentifierforthetaxiway.

6.11.1 atm:Taxipath

• Description:Asequenceoftaxiwaysfollowedbyanaircrafttaxiingenrouteto/fromarunway.• Superclasses:

o gen:Sequence

6.12 nas:Terminal

• Description:Astructureontheairportsurfacethatservesasaninterfacebetweenpeople,baggage,andaircraft.


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• Subclasses:Thereisasubclassofnas:Terminalforeachairport,andtheterminalinstancesaredistributedunderthosesubclasses.Note:Subclassesandinstanceswerecreatedonlyforfourairports:KDFW,KEWR,KJFK,andKLGA.

• Objectproperties:o nas:hasGate[nas:Gate]:Associatesanairportterminalwithaaircraftgatelocatedatthat

terminal.o nas:hasRampTower[nas:RampTower]:Associatesanairportterminalwitharamptowerthat

controllstheaircraftandvehicletrafficinthevicinityofthatterminal.• Datatypeproperties:

o nas:terminalID[string]:Thealphanumericidentifieroftheairportterminal.


Figure12:AirportsandRunways.ThisfigureillustratesaportionoftherepresentationforrunwaysatNewarkairport(KEWR).Ingeneral,airportsaredividedintoUSandinternationalairports.DuetothecloseproximityofCanadianairportstotheUSairspaceintheNortheast,thereisaspecialsubclassofnas:InternationalAirportforCanadianairports.USairportsaresplitintosubclassesforthoseinthecontinentalUSandthoseoutside.ThesedistinctionsarerelevantduetodifferentairtrafficproceduresinplacewhenflyingoutsidethecontinentalUSandbetweenCanadianandUSairports.Newarkairporthasthreephysicalrunways,eachofwhichcanbeoperatedwithplaneslandingortakingoffinonedirectionortheother.Thusconceptually,eachphysicalrunwayhastwoassociatedoperationalrunwaysintheontology.Forexample,thephysicalrunwaywithrunwayidentifier‘04L/22R’isassociatedwithtwooperationalrunwaysoriented180° apart:04L(40° heading)and22R(220° heading).Theoperationaldirectionalityoftherunwayisimportantbecausetherearedifferentpropertiesassociatedwitheitherdirection(therunwaytouchdownpointandtherunwayvisiblerange,forexample).

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Figure13:TerminalsandGates.ThisfigureillustratesaportionoftheontologyrepresentationforterminalsandgatesatNewarkairport(KEWR).(Notethattoreduceclutter,onlyasmallnumberofgatesaredepicted.)Terminalsandgatesarestructuredsimilarly.Theclassofterminalsispartitionedintosubclassescorrespondingtoairports.TheinstancesofterminalsatKEWR(TerminalsA,B,andC)allbelongtothesubclassnas:KEWRterminal.Theclassofgatesispartitionedintosubclassescorrespondingtoterminal.TheinstancesofgatesatKEWRTerminalA(includingA14,A25,andA13)allbelongtothesubclassnas:KEWRterminalAgate.Inaddition,theinstancesofterminalsandtheircorrespondinggatesarelinkedbythepropertynas:hasGate.

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7 Weather

Theclassesinthissectionpertaintothereportingofmeteorologicaldata.Anattempthasbeenmadetogeneralizeoverseveraldifferentsourcesofsurfaceweatherdatareportedforairports(specifically,METAR,TAF,ASPM);noattempthasbeenmadeasyettocaptureenroute,spatially-distributedmeteorologicalconditionsathighaltitude(e.g.,asreportedinCWAM,CCFPdatasources).

7.1 data:MeteorologicalCondition

• Description:Arepresentationofthemeteorologicalstatusforaspecifiedtimeperiod,includingsky,wind,visibility,andweathersubcomponents.Theclassdata:MeteorogicalConditionisthecentralorganizingclassfordescribingweatherconditions,includingpresentandprojected/forecastconditions.Theclassdata:MetConditionlinkstothisclassanditssubclassesprovidesdetailsofthesky,surface,weatherphenomena,andvisibilityconditions.ThisbasicclassisusedtouniformlydescribemeteorologicalconditionsasreportedbyASPM,METAR,andTAF.InTAFreports(data:TAFreport),forecastsarerepresentedassequences(gen:Sequence)ofmeteorologicalconditions,eachwithitsownvaliditytimeframe.


• Subclasses:o data:ASPMmeteorologicalConditiono data:METARreporto data:TAFmeteorologicalCondition

• Objectproperties:o hasSkyCondition[data:SkyCondition]:Linkstoskyconditionso hasSurfaceWindCondition[data:SurfaceWIndCondition]:Linkstosurfacewindconditionso hasVisibilityCondition[data:VisibilityCondition]:Linkstovisibilityconditionso hasWeatherCondition[data:WeatherCondition]:Linkstoweatherconditions

• Datatypeproperties:o data:meteorologicalConditionStatus[string:“observed”,“forecast”]:indicateswhetherthis

meteorologicalconditionrepresentsanactualobservationoraforecasto data:metConditionProbability[float]:anumberbetween0and1representingtheprobability

associatedwithaforecastmeteorologicalconditiono data:dewpoint[float]:ThetemperatureindegreesCelsiustowhichagivenparcelofairmustbe

cooledatconstantpressureandconstantwater-vaporcontentinorderforsaturationtooccur.o data:seaLevelPressure[float]:Sea-Levelpressureinhectopascals.Sea-levelpressureiscomputed

byadjustingthemeasuringstationpressuretocompensateforthedifferencebetweenthestationelevationandsea-level.

o data:surfaceTemperature[float]:SurfacetemperatureindegreesCelsius.

7.1.1 data:ASPMmeteorologicalCondition

• Description:MeteorologicalconditionsreportedaspartoftheASPMhourlyairportdata.Includessky,wind,visibilityandweathercomponents.

• Superclasses:o data:MeteorologicalCondition

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7.1.2 data:METARreport

• Description:Curentmeteorologicalconditionsarereportedinaperiodic(nominally,hourly)METARreport.Includessky,wind,visibilityandweathercomponents.


• Objectproperties:o data:associatedMETARreportingStation[data:METARreportingStation]:LinksaMETARreportto

thereportingstationwherethedatawerecollected.• Datatypeproperties:

o data:metarReportModifier[string:"AUTO","COR"]:AutomationstatusinformationpertainingtoaMETARreport:AUTOindicatesafullyautomatedreportwithnohumanintervention;CORindicatesacorrectedobservation;nomodifierindicateseitherhumanobserver/reporterorautomatedreportwithhumanoversight.

o data:metarReportString[string]:EntiretextofMETARreport.o data:metarReportType[string:"METAR","SPECI"]:METARreporttypeindicatorspecifies

whetherthisreportisaregularlyscheduledhourlyreport(METAR)oraspecialunscheduledreport(SPECI).SPECIsareissuedmorefrequentlythanhourlywhenadverseweatherconditionsprevail.

o data:metarStationiHasPrecipitationSensor[boolean]:AbooleanvalueindicatingwhetherthereportingMETARstationhasaprecipitationsensor.

7.1.2.1 data:METARreportingStation

• Description:AreportingstationthatprovidessensordataforaMETARreport.ManyairportsarealsoMETARreportingstations,buttherearealsonon-airportreportingstationswhereoperationalweathermonitoringhardwareisinstalled.

• Subclasses:o nas:Airporto nas:StandAloneWeatherStation

• Objectproperties:o data:hasMETARreport[data:METARreport]:AlinktotheMETARreportsforthisreportingstation

7.1.2.1.1 nas:StandAloneWeatherStation

• Description:Anon-airportlocationwhereoperationalweathermonitoringandreportinghardwareandsoftwareisinstalled.

• Superclasses:o data:METARreportingStation

• Note:Thisclassisaplaceholderandisnotmodeledinanydetail.

7.1.3 data:TAFmeteorologicalCondition

• Description:Aforecastmeteorologicalcondition,reportedaspartofaTAFforecast.Includessky,wind,visibilityandweathercomponentsforcurrentandfuturetimeperiods.


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• Datatypeproperties:o data:rapidityOfWeatherChange[string:"rapid","gradual","transient"]:Indicateshowfast

changeisexpectedfromthepriormeteorologicalconditionstothisforecastcondition.

7.1.3.1 data:TAFreport

• Description:ATAF(TerminalAerodromeForecast)reportpredictsmeteorologicalconditionsatsuccessivelylatertimepoints,startingatwiththecurrenttimepoint(andthecurrentactualconditions).TAFreportsaremodeledasasequence(gen:Sequence)offorecastmeteorologicalconditionsoveraspecifiedtimeperiod.

• Superclasses:o gen:Sequenceo data:IntervalData

• Objectproperties:o data:forecastingAirport[nas:Airport]:LinkstotheairportforwhichtheTAF(TerminalArea

Forecast)reportwascompiled.• Datatypeproperties:

o data:forecastIssueTime[datetime]:ThetimethattheTAF(TerminalAreaForecast)reportwasissued.

o data:tafReportString[string]:ThefulltextoftheentireTAFreport.o data:tafReportType[string:"routine","amended","corrected","delayed"]:TypeofTerminal

AreaForecastreport.AnamendedTAFisissuedwhenthecurrentTAFnolongeradequatelydescribestheongoingweatherortheforecasterfeelstheTAFisnotrepresentativeofthecurrentorexpectedweather.

7.2 data:MetCondition

• Description:Asuperclassovertheasetofclassesthatdefinedifferentaspectsofacurrentorforecastmeteorologicalcondition(data:MeteorologicalCondition).Ingeneral,thepropertiesandvaluesmodeledinthesubclassesofdata:MetConditionarederivedfromtheinternationalstandardMETARdefinitions.

• Subclasses:o data:SkyConditiono data:SurfaceWindConditiono data:WeatherConditiono data:VisibilityCondition

7.2.1 data:SkyCondition

• Description:Theskyconditionisrepresentedasasequenceofstacked,homogenouscloudlayers,startingwiththesurfaceandmovinguptotheceilingaltitude,abovewhichtheskyisclear.Thisisdoneusingastructurecalledacloudlayerprofile,whichislinkedtodata:SkyCondition.

• Superclasses:o data:MetCondition

• Objectproperties:o data:hasCloudLayerProfile[data:CloudLayerProfile]:Theclassdata:CloudLayerProfileisa

sequencecomposedofcloudlayers(data:CloudLayer).Eachcloudlayerhasdistinctproperties:

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itsbaselevelandtopmostaltitudes;thetypeofcloudpresent("toweringcumulus","cumulonimbus","altocumuluscastellanus");andthetypeofcloudcoverinthelayer("clear","fewclouds","scatteredclouds","brokenclouds","overcast","verticalvisibilitylayer")

• Datatypeproperties:o data:ceiling[integer]:Theverticalvisibility(infeet)measuredfromthegroundtothelowest

cloudlayerreportedasbrokenorovercast.

7.2.1.1 data:CloudLayer

• Description:Acloudlayerisahorizontalsliceoftheskythatexhibitsuniformcharacteristics,includingtheamountofcoverageandthetypeofcloudpresent.


• Datatypeproperties:o data:baseAltitude[integer]:thealtitudeinfeetofthebottomedgeofthelayero data:topAltitude[integer]:thealtitudeinfeetofthetopedgeofthelayero data:cloudCover[string:"clear","fewclouds","scatteredclouds","brokenclouds","overcast",

"verticalvisibilitylayer"]:thetypeofcloudcoverpresentinthelayero data:cloudType[string:"toweringcumulus","cumulonimbus","altocumuluscastellanus"]:the

typeofcloudpresentinthelayer

7.2.1.1.1 data:CloudLayerProfile

• Description:Asequenceofcloudlayers,orderedfromthegroundupward.Representsaverticalslicethroughthedistinctlayersofcloudsstartingatthesurface.

• Superclasses:o gen:Sequence

7.2.2 data:SurfaceWindCondition

• Description:Thesurfacewindsarespecifiedintermsoftheirspeed–bothsteady(data:surfaceWindSpeed)andgusting(data:surfaceGustSpeed)–anddirection.


• Datatypeproperties:o data:surfaceGustSpeed[float]:Reportedmaximumspeedofwindwhengusting,inknotso data:surfaceWindDirectionStatus[string:"fixed","varyingWithinRange","variable"]:When

data:surfaceWindDirectionStatusis“fixed”,thepropertydata:windDirectionFixedstoresthewinddirectionindegrees;whendata:surfaceWindDirectionStatusis“varyingWithinRange”,thepropertiesdata:windDirectionLoweranddata:windDirectionUpperholdthewinddirectioninterval;andwhendata:surfaceWindDirectionStatusis“variable”,thereisnospecificationofthewinddirection.

o data:windDirectionFixed[float]:Storeswinddirectionindegreeswhendata:surfaceWindDirctionStatusis“fixed”

o data:surfaceWindSpeed[float]:Reportedconstantspeedofwind,inknots

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o data:windDirectionLower[float]:Storeslowerboundofwindvariabilityintervalindegrees,wheretheintervalisdefinedclockwisebetweenthelowerandupperbound.Notethatthe‘lower’boundmaybenumericallygreaterthanthe‘upper’boundiftheintervalincludes0degrees(North).

o data:windDirectionUpper[float]:Storesupperboundofwindvariabilityintervalindegrees,wheretheintervalisdefinedclockwisebetweenthelowerandupperbound.Notethatthe‘lower’boundmaybenumericallylessthanthe‘upper’boundiftheintervalincludes0degrees(North).

o data:windShearHeight[float]:Windshearheightinfeetabovegroundlevel

7.2.3 data:WeatherCondition

• Description:Thisclassholdspropertiesdescribingobservedorforecastweatherphenomena,alongwiththeirintensity,proximity,andotherrelatedcharacteristics.ThepropertiesandtheirvaluesarederivedfromtheinternationalstandardWMOMETARdefinitions.


• Datatypeproperties:o data:hourlyPrecipitation[float]:precipitationininches,tothehundredthofanincho data:weatherIntensity[string:"light","moderate","heavy"]o data:weatherPhenomenon[string:"drizzle","rain","snow","snowgrains","icecrystals","ice

pellets","hail","smallhailand/orsnowpellets","unknownprecipitation","mist","fog","smoke","volcanicash","widespreaddust","sand","haze","spray","well-developeddust/sandwhirls","squalls","funnelcloud","tornado/waterspout","sandstorm","duststorm"]

o data:weatherProximity[string:"immediateproximity","invicinity"]o data:weatherQualifier[string:"shallow","partial","patchy","lowdrifting","blowing",

"shower","thunderstorm","freezing"]

7.2.4 data:VisibilityCondition

• Description:Thisclassdescribesvisibilityconditionsatanairportintermsoftwotypesofmeasurements:theprevailingvisibilitymeasuredatanairportandtherunwayvisiblerangemeasuredalongoneormoreairportrunways.Theprevailingvisibilityisameasurementofthegreatestdistancevisiblethroughoutatleasthalfofthehorizon,notnecessarilycontinuously.Thatdistanceiseitherlimitedorunlimited.Ifthepropertydata:unlimitedVisibilityiseitherfalseornotspecified,thenthelimitofvisibilityistobespecifiedindata:limitedVisibilityDistance;ifdata:unlimitedVisibilityistrue,thenthedistancelimitisleftunspecified.Anyavailablemeasurementsofrunwayvisiblerangearelinkedusingthepropertydata:runwayVisibleRange.


• Objectproperties:o nas:runwayVisibleRange[nas:RunwayVisibleRangeMeasurement]:Anindicationoftherangeof

distancepastwhichtherunwaysurfacemarkingsbecomeunreadableforthepilot• Datatypeproperties:

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o data:limitedVisibilityDistance[float]:Ifprevailingvisibilityislimited,thispropertyholdsthesurfacevisibilitydistanceinstatutemiles

o data:unlimitedVisibility[boolean]:Trueifprevailingvisibilityisunlimited

7.2.4.1 nas:RunwayVisibleRangeMeasurement

• Description:Ameasurementofthedistanceoverwhichapilotofanaircraftonthecenterlineofarunway(linkedvianas:runwayMeasured)canseetherunwaysurfacemarkingsdelineatingtherunwayanditscenterline.RVR(RunwayVisibleRange)isreportedaseitherconstantorvariable.Variableprevailingvisibilityisreportediftheprevailingvisibilityislessthan3milesandrapidlyincreasesordecreasesby1/2statutemileormoreduringthetimeofobservation.Ifthevisibilityisconstant,thenthenas:minVisibilityandnas:maxVisibilitypropertieswillbeequal;ifthevisibilityisvariable,thenthesepropertiesspecifytheminimumandmaximumnumberoffeetvisible.


• Objectproperties:o nas:runwayMeasured[nas:OperationalRunway]:Therunwayforwhichvisibilityisbeing

measured.• Datatypeproperties:

o nas:maxVisibility[integer]:Maximumdistance(infeet)atwhichsurfacemarkingsbecomeinvisible

o nas:minVisibility[integer]:Minimumdistance(infeet)atwhichsurfacemarkingsbecomeinvisible

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Figure14:METARReport.ThisfigureillustratesthestructureofaMETARreport(data:METARreport)andrelatedsubclassesofdata:MeteorologicalCondition,includingTAFreportsandASPMweatherindicators.TheillustratedMETARreportwasissuedon7/15/2014at19:14UTCbasedondatafromsensorsatKJFK.TherawMETARreportconsistsofthefollowingWMOstandards-compliantMETARtextstring:‘KJFK151914Z17008KT4SMR04R/3500VP6000FT+TSRABRFEW017BKN042CBOVC07023/21A2980RMKAO2FRQLTGICCGNE-STSNE-SMOVNEP0014’.Meteorologicalconditionswereextractedfromthisstringandre-encodedwithintheontologystructureshowninthisfigure.AttherootofthisstructureisanoderepresentingtheoverallMETARreportinstance(data:METAR_KJFK201407151914).Thereisalinkfromthisnodetothereportingstationthatgeneratedthedataforthereport(inthiscaseKJFKairport).Thereportincludesdataaboutfourdifferentmeteorologicalcomponents:weather,visibility,skycloudcover,andwinds.EachofthesecomponentsisrepresentedinaseparateinstancelinkedtotheMETARreportinstance.Theweatherandwindcomponentsincludeonlydatatypeproperties,andhavenolinkingsubstructure.Thevisibilityconditionincludesalinktoarunwayvisiblerange(RVR)measurementinstance.ThatinstanceincludesvaluesforthemaximumandminimumrunwayvisibilityandalinktotheactualrunwayatKJFKbeingmeasured(Runway04R).Theskyconditioncomponentislinkedtoastructurecalledacloudlayerprofile,whichisasequenceofcloudlayers(data:CloudLayer)orderedfromthegroundupward.Thecloudlayerprofilerepresentsaslicethroughtheskiesabovethereportingstation.Eachsequencedcloudlayerhasalowerandupperaltitudeandrepresentsahomogeneouscloudlayerwithaspecifiedcloudcovertypeanddensity.See7.2.1.1.

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Figure15:TAFReport.ThisfigureillustratesthestructureofaTAFreport(data:TAFreport),whichprovidesmeteorologicalforecastsoveraspecifiedperiodoftime–typically24hours.ThegraphstructureinthisfigureillustratesaTAFreportasspecifiedinthefollowingWMOstandardTAFtextstring:‘TAFKJFK071120Z0712/081821010KTP6SMBKN070FM07150019015KTP6SMSCT060FM07190019018G25KTP6SMSCT060BKN250FM07230019016KTP6SMSCT060BKN250FM08020020010KTP6SMSCT060BKN250FM08130022012KTP6SMSCT060SCT250’.Meteorologicalconditionswereextractedfromthisstringandre-encodedwithintheontologystructureshowninthisfigure.TheforecastperiodforthisTAFisfrom7/7/2014at12:00UTCthrough7/8/2014at18:00UTC,andthereportisaforecastforKJFKairport.TherootnodeoftheTAFreportincludessomepropertiesrelatedtothereport’stimeofissueandincludestheTAFtextstring,butthemainfunctionofthisnodeistopointtothesequenceofnodesthatcomprisetheTAFforecast.TheitemsintheTAFsequenceeachcorrespondtoadifferentpredictedTAFmeteorologicalcondition(data:TAFmeteorologicalCondition).Eachconditioncoversaspecifiedtimerangeandprovidestheforecastsky,visibility,wind,andweatherconditions.Forexample,thefirstforecastperiod(data:TAFKJFK201407071120F1)islinkedtotherootnodeviathepropertygen:hasFirstItem,andexhibitsthesamebasicstructureastheMETARreportinFigure14.Butinaddition,thefirstforecastperiodislinkedtothenextperiod,whichhasthesamestructureasthefirstperiod.(Thesky,visibility,wind,andweatherconditionsarenotdisplayedforeachforecastperiodtoreduceclutter.)Inessence,aTAFreportcanbeviewedstructurallyasasequenceofMETARreports.AkeydifferenceisthatMETARreportsactualobservationsataspecifictime,whereasTAFreportsasequenceofsuccessiveforecastconditions,eachvalidforthedurationofaspecifiedtimeperiod.

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8 Sequences,Subsequenes,SequencedItems

Theclassesinthissectiondefinethenotionofasequence,whichisanimportantstructuringconceptusedthroughouttheontology.Asequence(gen:Sequence)representsanordered,linkedlistoftypedinstances.Forexample,anaircrafttrajectoryisrepresentedasasequenceofaircrafttrackpoints,whereeachtrackpointrecordstheGPScoordinatesandaltitudeoftheaircraftatsuccessivetimepointsthroughouttheflight.Anotherexampleofasequenceisaweatherforcast,whichisrepresentedasasequenceofmeteorologicalconditions,eachprojectedataspecifiedtimepointinthefuture.Anyclasscanbesequencedaslongasitinheritsthenecessarypropertiesfromgen:SequencedItem.Notethatthesequenceisdistinctfromtheitemsbeingsequenced.Thesequencepointstothefirst,last,andinterveningitemsinthesequence;eachofthoseitemspointstothenextandpreviousiteminthesequence.

8.1 gen:Sequence

• Description:Anorderedsequenceofinstances.Asequenceismodeledasalinkedlistofacertainlength,containinginstancesoftheclassgen:SequencedItem.Asequenceislinkedtoallitemsinitsorderedlist,withspeciallinkstothefirstitemandthelastitem.Eachiteminthesequenceisnumberedsequentiallyandpointstothenextinthelist.Foragivensubclassofgen:Sequence,thecontentsofthelistaregenerallyrestrictedtoonlyonesubclassofgen:SequencedItem.(ThisrestrictionisimplementedasanOWLrestrictionoftypeowl:allValuesFrom.)Inotherwords,thelistmaybeconstrainedtocontainonlyhomogeneoustypesofinstances.Forexample,apolygonboundary(gen:PolygonBoundary)isasequencecontainingonlypointlocations(gen:PointLocation).

• Subclasses:o atm:FlightSequence[sequenceofatm:AircraftTrackPointoratm:NavElementContainer]

§ Description:Anend-to-endflightplanoractualflightpathrepresentedasasequenceofnavigationalelementsfollowedfromorigintodestinationairport.

§ Subclasses:• atm:ActualFlightRoute[sequenceofatm:AircraftTrackPoint]:Seedetailsin

Section3.8.• atm:PlannedFlightRoute[sequenceofatm:NavElementContainer]:Seedetails

inSection3.4.o atm:NavigationPath[sequenceofatm:NavElementContainer]

§ Description:Anorderedsequenceofnavigationelements(fixes,routes,airports)representingapaththroughtheairspace.

§ Subclasses:• atm:PlannedFlightRoute[sequenceofatm:NavElementContainer]• nas:AirspaceRoute[sequenceofatm:NavElementContainer]

o atm:PopupFactorSequence[sequenceofatm:PopupFactorContainer]§ Description:AnorderedsequenceofhourlypopupfactorsusedinspecifyingaGround

DelayProgram(GDP).o atm:ProgramArrivalRateSequence[sequenceofatm:ProgramArrivalRateContainer]

§ Description:AnorderedsequenceofhourlyprogramarrivalratesusedinspecifyingaGroundDelaProgram(GDP).

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o atm:Taxipath[sequenceofnas:Taxiway]§ Description:Asequenceoftaxiwaysfollowedbyanaircrafttaxiingenrouteto/froma

runway.o data:CloudLayerProfile[sequenceofdata:CloudLayer]

§ Description:Asequenceofcloudlayers,orderedfromthegroundupward.Representscloudconditions.

o data:TAFreport[sequenceofdata:TAFmeteorologicalCondition]§ Description:MeteorologicalconditionsprovidedinaperiodicTAFforecast.Includessky,

wind,visibilityandweathercomponents.(Seefurtherdetailsondata:TAFreportinSection7.1.3.1.)

o gen:PolygonBoundary[sequenceofgen:PointLocation]§ Description:Anorderedsequenceofpointlocationswherethelastpointconnectsback

tothefirstpoint,closingthepolygon.o nas:DeicingQueue[sequenceofeqp:Aircraft]

§ Description:Anorderedsequenceofaircraftawaitingdeicingatadeicingpad.• Objectproperties:

o gen:hasFirstItem[gen:SequencedItem]:Linksasequencetothefirstitembeingsequenced.o gen:hasLastItem[gen:SequencedItem]:Linksasequencetothelastitembeingsequenced.o gen:hasSequencedItem[gen:SequencedItem]:Linksasequencetoanitembeingsequenced.The

firstandlastitemsinthesequenceshouldbelinkedusingboththispropertyandthedistinguishedpropertiesabove.

• Datatypeproperties:o gen:sequenceLength[integer]:Thenumberofitemsintheorderedsequence.

8.1.1 gen:SubSequence

• Description:Representsasubsequenceofanexistingbasesequence.Thesubsequencedoesnotreplicatetheitemsofthesequence,butmerelypointstothestartandendpositionswithinthebasesequence.Thisisused,forexample,tospecifythataflightistofollowaportionofanestablishedairspacerouteaspartoftheirflightplan.

• Subclasses:o atm:NavigationSubPath:Acontiguousportionofanexistingnavigationpath.

§ atm:AirspaceRouteSegment:Acontiguousportionofanexistingairspaceroute.§ atm:FlightPlanSegment:Acontiguousportionofacompleteflightplan.

• Objectproperties:o gen:subsequenceOf[gen:Sequence]:Linksasubsequencetoitsbasesequence.

• Datatypeproperties:o gen:subsequenceStartIndex[integer]:Anumericpositionwithinabasesequencethatrepresents

thestartofthesubsequence.o gen:subsequenceEndIndex[integer]:Anumericpositionwithinabasesequencethatrepresents

theendofthesubsequence.

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8.2 gen:SequencedItem

• Description:Thesetofinstancesthatcanbesequencedusinggen:Sequence.Thisclassdefinestwopropertiesthatfacilitatesequencing:apointertothenextinstanceinthesequence,andasequencenumberindicatingthepositionwithinthesequence.

• Subclasses:Sequencedinstancesmustbemembersofoneofthefollowingsubclasses.(Notethatthesesubclassessharenothingincommonconceptually,exceptthattheycanbesequencedforsomepurpose.)

o atm:AircraftTrackPointo atm:NavElementContainero atm:NumericParameterContainer

§ atm:PopupFactorContainer§ atm:ProgramArrivalRateContainer

o data:CloudLayero data:TAFmeteorologicalConditiono eqp:Aircrafto gen:PointLocation

• Objectproperties:o gen:hasNextItem[gen:SequencedItem]:Linksaninstanceinasequencetothesubsequent

instanceinthesequence.• Datatypeproperties:

o gen:sequenceNumber[integer]:Indicatestheorderedpositionofthisinstancewithinthesequence,where1signifiesthefirstpositioninthesequence.


Figure16:SequencesandSubsequences.Inpreviousfigures,therearemanyconcreteexamplesofsequences.Thisfigureillustratesanabstractinstanceofasequencenamednas:SampleSequence,whichcontainsanorderedsequenceofsamples(nas:Sample1throughnas:Sample4).Eachsampleislinkedtothesequenceinstanceusingthepropertygen:hasSequencedItem.Inaddition,therearespecialpropertiestoidentifythefirstandlastitemsinthesequence(gen:hasFirstItemandgen:hasLastItem).Eachitemintheinthesequenceislinkedtoitssuccessorthroughthegen:hasNextItemproperty,andthepositionwithinthesequenceisrecordedinthedatatypepropertygen:sequenceNumber.Finally,torepresentthesubsequenceofelementsinnas:SampleSequencethatstartsinposition2andendsinposition3,weuseasubsequenceinstance(nas:SampleSubSequence),whichavoidsduplicatingtheitemsinthesequence.Datatypepropertiesinnas:SampleSubSequenceholdthesequencenumberofthestartingandendingsubsequencepositionsandthepropertygen:subsequenceOflinkstothemainsequence.

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9 Temporal/Spatial

Theclassesinthissectiondescribegeneralconceptspertainingtotimeandspace.VerylittlehereisspecifictotheATMdomain.(Infact,mostoftheseconceptsaresobasicthattheycouldhave–andprobablyshouldhave–beenimportedfromotherwell-establishedexternalontologies.Thiswouldbeanareaforfutureimprovement.)

9.1 data:IntervalData

• Description:Thisclassincludesdatathathasatemporallifetime.Allsubclassesofdata:IntervalDatainheritthebasicpropertiesthatenabletemporally-dependentdata–thedata’speriodofvalidity,asdefinedbyastartingandanendingtime.

• Subclasses:o atm:AircraftFlowCapacityo data:AirportDatao data:MeteorologicalConditiono data:RunwayStatusDatao data:TAFreporto nas:RunwayVisibleRangeMeasurement

• Objectproperties:o data:dataIntervalEndDay[nas:NASday]:Linkstemporally-dependentdatatotheendingdayofits

periodofvalidity.o data:dataIntervalStartDay[nas:NASday]:Linkstemporally-dependentdatatothestartingdayof

itsperiodofvalidity.• Datatypeproperties:

o data:dataIntervalEndTime[dateTime]:Fortemporally-dependentdata,theendingtimeofthedata'speriodofvalidity.

o data:dataIntervalStartTime[dateTime]:Fortemporally-dependentdata,thestartingtimeofthedata'speriodofvalidity.

9.2 gen:TimeInterval

• Description:Atimeintervalwithstartingandendingtimepoints.Intervalscanbeopen(excludingtheendpoints)orclosed(includingtheendpoints)ormixed(includingonebutnottheotherendpoint).

• Notes:Thisistheproperwaytodoatimeintervalandthisrepresentationeventuallyshouldreplacethelessgeneralrepresentationscurrentlyusedinvariousclasses

• Datatypeproperties:o gen:closedEndTimeInterval[boolean]:Apropertythatspecifieswhetherornottheendpointof

thetimeintervalisclosed(inclusiveofthepoint).o gen:closedStartTimeInterval[boolean]:Apropertythatspecifieswhetherornotthestarting

pointofthetimeintervalisclosed(inclusiveofthepoint).o gen:endTime[dateTime]:Theendingtimeofadefinedtimeinterval.o gen:startTime[dateTime]:Thestartingtimeofadefinedtimeinterval.

9.3 nas:NASday

• Description:Aclassthatexplicitlyrepresentsadayoftheyear.Events,suchasflights,weatherforecasts,andothereventsarelinkedtotheinstanceofthedaytheyoccurred.

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• Datatypeproperties:o nas:calendarMonth[integer]:Themonthnumberassociatedwithanas:NASday.o nas:calendarYear[integer]:Theyearnumberassociatedwithanas:NASday.o nas:date[date]:Thedaterepresentedbythenas:NASday,storedindateformat.o nas:dayOfMonth[integer]:Thedaynumberassociatedwithanas:NASday.

9.4 nas:NAShour

• Description:Aclassthatexplicitlyrepresentsanhourwithinaday.Events,suchasflights,weatherforecasts,andothereventsarelinkedtotheinstanceofthehourtheywereinitiated.

• Datatypeproperties:o nas:startingTime[time]:Thebeginningofthehourrepresentedbythenas:NAShour,storedasa

datetimevalue.

9.5 gen:Location

• Description:Aplacedefinedbyapointoracontiguousgeographicregion.• Subclasses:

o gen:GeographicRegion§ gen:Region2D

• gen:CircularRegion• gen:Polygonal2DRegion

§ gen:Region3D• gen:ShearSidedPolygonalVolume

o gen:PointLocation§ atm:AbsoluteFix

• Datatypeproperties:o gen:WKTgeoRepresentation[string]:TheWKTstringrepresentationofalocation.Well-Known

Text(WKT)isanISO/IECstandards-basedatextmarkuplanguageforrepresentingvectorgeometryobjectsonamap,spatialreferencesystemsofspatialobjects,andtransformationsbetweenspatialreferencesystems.WKTisstoredasanalternativetotheexplicitpolygonboundaryrepresentationemployedinthisOntology(seegen:PolygonBoundary).

9.5.1 gen:GeographicRegion

• Description:AclassrepresentingademarcatedregiononorabovethesurfaceoftheEarth.• Superclasses:

o gen:Location

9.5.1.1 gen:Region2D

• Description:Atwo-dimensionalgeographicregion.• Superclasses:

o gen:GeographicRegion• Subclasses:

o gen:CircularRegiono gen:Polygonal2DRegion

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9.5.1.1.1 gen:CircularRegion

• Description:Atwo-dimensionalregiondefinedbyageographiccenterpointandradius.• Objectproperties:

o gen:centerpoint[gen:PointLocation]:Linkstothecenterpointofthe2-Dcircularregion.• Datatypeproperties:

o gen:radius[float]:Theradiusofacircularregion.Note:Unfortunately,theunitsarecurrentlydependentthetypeofcircularregiondefined.Thisneedstobeimproved.

9.5.1.1.2 gen:Polygonal2DRegion

• Description:Atwo-dimensionalregiondefinedbyapolygonalboundary.• Objectproperties:

o gen:hasPolygonBoundary[gen:PolygonBoundary]:Linksapolygonalregiontoitsboundaryrepresentation.

9.5.1.2 gen:Region3D

• Description:Athree-dimensionalgeographicregion.• Superclasses:

o gen:GeographicRegion• Subclasses:

o gen:ShearSidedPolygonalVolume

9.5.1.2.1 gen:ShearSidedPolygonalVolume

• Description:Athree-dimensionalvolumedefinedbyatwo-dimensionalpolygonplusalengthcomponentthatstretchesthepolygonalonganaxisperpendiculartothepolygonsurface.

• Objectproperties:o gen:hasPolygonBoundary[gen:PolygonBoundary]:Linksapolygonalregiontoitsboundary

representation.• Datatypeproperties:

o gen:polygonHeight[float]:Specifiesthelengthdimensionofapolygonalvolume.Note:Thelengthunitsareuse-dependent.

9.5.2 gen:PointLocation

• Description:Alocationinthree-spacedefinedbyalatitude,longitude,andaltitude.• Superclasses:

o gen:Locationo gen:SequencedItem

• Subclasses:o atm:AbsoluteFix

• Datatypeproperties:o gen:altitude[float]:Thealtitudeofapointlocationinfeet.o gen:latitude[float]:Thelatitudeofapointlocationindecimaldegrees.o gen:longitude[float]:Thelatitudeofapointlocationindecimaldegrees.

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9.5.2.1 gen:PolygonBoundary

• Description:Anorderedsequence(gen:Sequence)ofindividualpointlocationinstances(gen:PointLocation),wherethelastpointconnectsbacktothefirstpoint,closingthepolygon.

• Note:Thisisanexplicit,alternativerepresentationtotheWKTstringrepresentationstoredinthegen:WKTgeoRepresentationpropertyofthegen:Locationclass.

• Superclasses:o gen:Sequence


Figure17:Sectorlayerrepresentation.ThisfigureextendsFigure1andillustratesthespatialrepresentationforoneofthesectorlayerscomposingSector075inNewYorkCenter(ZNYARTCC).Eachsectorconsistsofasetofhorizontally-stackedpolygonallayerswithshearverticalsides,somethinglikealayercake.Eachsectorisrepresentedwiththreecomponents,aloweraltitude,anupperaltitude,andalayergeometry.Thegeometryprovidestheheightofthelayer(gen:polygonHeight)andalink(gen:hasPolygonBoundary)toarepresentationofthepolygonboundary.Theboundaryisrepresentedasanorderedsequenceofpointlocations(gen:PointLocation),eachofwhichspecifiesalatitudeandlongitude.Notethatthepropertygen:WKTgeoRepresentationingen:ZNYsector075Layer1PolygoncontainsanalternativerepresentationoftheboundaryintheWellKnownText(WKT)format.

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Figure18:Circularairportradius.ThisfigureillustratestheuseofacirculargeographicregiontodefinethescopeofaGroundDelayProgram(GDP)TMI.TheGDP’sdeparturescopespecifiesthattheTMIisapplicabletoanyaircraftdepartingwithinan800mileradiusaroundKDEN.Theinstanceatm:KDENradius800isacircularregionwithacenterpointspecifiedbynas:KDENcoordinates,whichspecifiestheairport’sgeographiccenter.

Figure19:Temporalrepresentationforairportdata.Inthisfigure,data:KEWRairportData20140701230000representsaninstanceofdata:AirportData.ThisinstancestoresdatathataremeasuredhourlyatmajorairportsintheUS,suchasKEWR.Theinstanceinheritsthepropertiesofdata:IntervalData,includingthedata’speriodofvalidity,asspecifiedbyastartingandendingvaliditytimeandlinkstothestartingandendingdays(nas:Day20140701andnas:Day20140702).

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10 Appendices

AppendixA References

[1] A.DoanandA.Y.Halevy,"Semanticintegrationresearchinthedatabasecommunity:Abriefsurvey,"AImagazine,vol.26,p.83,2005.

[2] N.F.Noy,"Semanticintegration:asurveyofontology-basedapproaches,"ACMSigmodRecord,vol.33,pp.65-70,2004.

[3] R.M.Keller,S.Ranjan,M.Y.Wei,andM.M.Eshow,"SemanticRepresentationandScale-upofIntegratedAirTrafficManagementData,"inInternationalWorkshoponSemanticBigData,SanFrancisco,California,2016.

[4] R.M.Keller,"OntologiesforAviationDataManagement,"in2016IEEE/AIAA35thDigitalAvionicsSystemsConference(DASC),Sacramento,2016.

[5] R.M.Keller,"DataIntegrationUsingtheNASAAirTrafficManagementOntology,"presentedattheSemanticWebforAirTransportation(SWAT-2015),Washington,DC,2015.Available:https://www.faa.gov/nextgen/programs/swim/governance/servicesemantics/media/NASAATMOntologyforSWATrevised.pdf

[6] R.M.Keller,"NASA'sATMOntology,"presentedattheAirTransportationInformationExchangeConference,SilverSpring,MD,2015.Available:http://www.aixm.aero/sites/aixm.aero/files/imce/library/ATIEC_2015/38_day3_nasas_atm_ontology_semantic_integration_and_querying_across_nas_data_sources.pdf

[7] W3C.(2014).OWL2WebOntologyLanguageDocumentOverview(SecondEdition).Available:https://www.w3.org/TR/owl2-overview/

[8] W3C.(2014).RDF1.1ConceptsandAbstractSyntax.Available:http://www.w3.org/TR/rdf11-concepts/[9] W3C.(2014).RDFSchema1.1.Available:http://www.w3.org/TR/rdf-schema/

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AppendixB OntologyNamespaces

ClassesdefinedintheontologyareseparatedintodifferentXMLnamespacestofacilitatemodularityandreuse,andtoreducecomplexity.Theprimarypurposeforusingnamespacesinthisontologyistoseparatethelargenumberofclassesintoasmallerclustersofthematically-interrelatedclasses.Althoughthereisahighdegreeofinterconnectednessandcross-linkingamongclasseswithinthesamenamespace,classesalsocanmakereferencetoclassesoutsidetheirownnamespace.Thesereferencesareresolvedbytheuseofimportstatements,themechanismbywhichonenamespaceimportsanother.

IntheATMOntology,thenamespaceimportrelationshipsarestructuredlinearly,asdepictedontheleft.Thedatanamespaceimportsalloftheclassesintheontologybecauseitdirectlyimports

classesintheatmnamespace,whichindirectlyimportsconceptsfromnas,eqp,andgen.Thesefivenamespacesaredescribedinthefollowingsubsections.

Notethatthepartitioningofclassesintonamespacesisnotalwaysstraightforwardandunambiguous;rationalargumentsarepossibleforincludingagivenclassinadifferentnamespacethantheonehereinassigned.

B.1 Namespacegen:Generic,domain-independentclasses

• Prefix:gen• NamespaceURI:http://atmweb.arc.nasa.gov/ontology/general#• Description:Thisnamespacecontainsclassesthataregeneral-purpose,andnotspecifictotheairtraffic

oraviationdomain.Theseincludetemporal,spatial,andsequencingclasses.Thisisthebasenamespacethatisinherited(directlyorindirectly)byallothernamespaces.

• Classes:o gen:CircularRegiono gen:FloatParametero gen:GeographicRegiono gen:IntegerParametero gen:Locationo gen:NumericParametero gen:PointLocationo gen:Polygonal2DRegiono gen:PolygonBoundaryo gen:Region2Do gen:Region3Do gen:Sequenceo gen:SequencedItemo gen:ShearSidedPolygonalVolumeo gen:SubSequenceo gen:TimeInterval

B.2 Namespaceeqp:Equipment-relatedclasses

• Prefix:eqp• NamespaceURI:http://atmweb.arc.nasa.gov/ontology/eqp#

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• Imports:gen• Description:Thisnamespacecontainsclassesrelatedtoaircraft,aircraftmodels,aircrafttypedesignators,

aircraftweightandwakecharacteristics,anddecomposableengineeringsystems,ingeneral.• Classes:

o eqp:Aircrafto eqp:AircraftCommunicationSystemo eqp:AircraftEngineo eqp:AircraftModelo eqp:AircraftNavigationSystemo eqp:AircraftSubsystemo eqp:AircraftTypeo eqp:AircraftWakeCategoryo eqp:AircraftWeightClasso eqp:BallBearingo eqp:DecomposableSystemo eqp:ElectricalPowerSystemo eqp:EngineeredSystemo eqp:EngineTypeo eqp:NavigationAido eqp:UnitAssembly

B.3 Namespacenas:NationalAirspaceSystem-relatedclasses

• Prefix:nas• NamespaceURI:http://atmweb.arc.nasa.gov/ontology/nas#• Imports:eqp• Description:ThisnamespacedefinesclassesthatdefinetheoverallNationalAirspaceSystem(NAS)

infrastructure,includingNASfacilities(theFAAcommandcenter,Airports,ARTCCs/Centers,TRACONs),airportsurfacestructures(controltowers,runways/taxiways,terminals,gates),airspacestructures(routes,sectors,approachanddepartureprocedures),andaviationserviceproviders(aircarriers,manufacturers,airnavigationserviceproviders),

• Classes:o nas:AirCarriero nas:AircraftEngineManufacturero nas:AirframeManufacturero nas:Airporto nas:AirportInfrastructureComponento nas:AirportRouteo nas:AirportServiceVehicleo nas:AirspaceInfrastructureComponento nas:AirspaceLayero nas:AirspaceRouteo nas:ARTCCo nas:ARTCCtiero nas:ATCSCC

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o nas:ATCTo nas:AviationIndustryManufacturero nas:AviationServiceProvidero nas:CanadianAirporto nas:CommonRouteo nas:CONUSairporto nas:DeicingPado nas:DeicingQueueo nas:DeicingTrucko nas:FederalAirwayo nas:Gateo nas:GovernmentAviationServiceProvidero nas:InternationalAirporto nas:JetRouteo nas:NASdayo nas:NASfacilityo nas:NAShouro nas:NonCONUSairporto nas:OperationalRunwayo nas:PhysicalRunwayo nas:QRouteo nas:RadialRouteo nas:RampTowero nas:RefuelingTrucko nas:RNAVrouteo nas:RunwayVisibleRangeMeasuremento nas:Sectoro nas:SIDo nas:SIDSTARo nas:SIDSTARrouteo nas:StandAloneWeatherStationo nas:STARo nas:Taxiwayo nas:Terminalo nas:TRACONo nas:TransitionRouteo nas:TRouteo nas:USairporto nas:VictorRouteo nas:VORroute

B.4 Namespaceatm:AirTrafficManagement-relatedclasses

• Prefix:atm• NamespaceURI:http://atmweb.arc.nasa.gov/ontology/atm#

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• Imports:nas• Description:Thisnamespacedefinesclassesthatspecificallyrelatetothecontrolofairtrafficthroughthe

NAS,includingTrafficManagementInitiatives(TMIs)andairnavigationstructures(fixes,paths/routes,flightplans).

• Note:Theborderlinebetweentheclassesinthisnamespaceandthenasnamespace(whichisimportedbyatm)isnotclearcut;reasonableargumentscanbemadeaboutwhichnamespaceismoreappropriateforagivenclass.

• Classes:o atm:AbsoluteFixo atm:ActualFlightRouteo atm:AircraftCapacityo atm:AircraftFlowo atm:AircraftFlowCapacityo atm:AircraftTrackPointo atm:AirportFixo atm:AirportSpeco atm:AirspaceFlowProgramTMIo atm:AirspaceRouteSegmento atm:CrewMembero atm:DelayModelo atm:Flighto atm:FlightPlanSegmento atm:FlightSpeco atm:FRDfixo atm:GPSfixo atm:GroundDelayProgramTMIo atm:GroundStopTMIo atm:IntersectionFixo atm:LatLonFixo atm:MeterFixo atm:MilesInTrailTMIo atm:NavaidFixo atm:NavElementContainero atm:NavigationElemento atm:NavigationFixo atm:NavigationPatho atm:NavigationSubPatho atm:NDBfixo atm:NRSfixo atm:NumericParameterContainero atm:PlannedFlightRouteo atm:PopupFactoro atm:PopupFactorContainero atm:PopupFactorSequence

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o atm:ProgramArrivalRateo atm:ProgramArrivalRateContainero atm:ProgramArrivalRateSequenceo atm:RelativeFixo atm:ReRouteSegmento atm:ReRouteTMIo atm:SIDSTARtraverseo atm:TACANfixo atm:Taxipatho atm:TFMcontrolElemento atm:TrafficManagementInitiativeo atm:VORfix

B.5 Namespacedata:Data-specificclasses

• Prefix:data• NamespaceURI:http://atmweb.arc.nasa.gov/ontology/data#• Imports:atm• Description:Thisnamespaceincludesclassesrequiredtodefinedata-specificconceptsrelatedto

meteorologicaldata(includingsky,wind,visibility,andweatherconditions),aswellasrunwaystatusandairportarrival,departure,flow,andcapacitystatistics.TheseclassescoverdataassociatedreportedfromMETAR,TAF,andASPMsources.

• Classes:o data:AirportDatao data:ASPMmeteorologicalConditiono data:CloudLayero data:CloudLayerProfileo data:FixCapacityo data:FixFlowo data:IntervalDatao data:METARreporto data:METARreportingStationo data:MetConditiono data:MeteorologicalConditiono data:RunwayStatusDatao data:SectorCapacityo data:SectorFlowo data:SkyConditiono data:SurfaceWindConditiono data:TAFmeteorologicalConditiono data:TAFreporto data:VisibilityConditiono data:WeatherConditiono data:WITIproperty

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AppendixC SubsumptionHierarchy

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AppendixD NotesontheOntology

• Ontologyscoping:Thescopingandfocusofthisontologywasprimarilyapplicationdriven.Wedesigneddatatypeproperties(andcorrespondingclasses)thatwouldenableustostoreallthetypesofdatavaluesthatwerecapturedbythedifferentaviationdatasourceswesoughttointegrate.Whileweattemptedtomaketheclassesandpropertiesasgeneralandreusableaspossible,achievinggeneralitywhilesatisfyingspecificneedsandapplicationrequirementscanbeadifficultproposition.Incaseswherenoimmediaterequirementswerepresenttodefineacertainclass,buttheclassisobviouslywarranted,themodelingisthin,andservesonlyasaplaceholder.

• Improvementareas:o Representationoftimeintervals:Currently,thereisanmixtureofrepresentationsusedwithinthe

Ontologyfortimeintervals.Forexample,theactualoperatingtimeforaflightiscurrentlyrepresentedbytwoseparatepropertiesatm:actualDepartureTimeandatm:actualArrivalTime.Thismightberepresentedalternativelywithonepropertythatlinkstoaninstanceofgen:TimeInterval.Thesituationissimilarforatm:TrafficManagementInititive,whichusesatm:effectiveStartTimeandatm:effectiveEndTimetomarktheintervalthataTMIistobeenforced.Theclassgen:TimeIntervalallowsformoreflexibilityconcerningwhethertheintervalendpointsareopenorclosed,andisamoreappropriate,morefine-grainedrepresentationtouseinsomesituations.Forinstance,theclassnas:NAShourisdefinedtohaveastarttimeonly.Implicitly,theendtimeistheendofthehour.Amorecorrectrepresentationwoulduseatimeintervalwithaclosedstartingtimepoint(atthebeginningofthehour)andanopenendingtimepoint(atthebeginningofthenexthour).

o Treatmentofunits:Ingeneral,measurementunitsareimplicitinthisOntology.Sometimesthemeasurementunitsareembeddedinthepropertynames(e.g.,nas:runwayLengthInFeet);othertimes,theunitsaredefinedinthisdocument(e.g.,gen:altitude[float]:Thealtitudeofapointlocationinfeet);othertimestheunitsareunstatedordefinedbyconvention(e.g.,data:hourlyPrecipitation[float],whichisinmillimetersbyWMOstandards).Thistreatmentisunsatisfactoryandshouldberemedied.Note,however,thattheprocessingandstorageburdenimposedbyexplicitlyassociatingunitinformationwitheachmeasurementwouldlikelybeunacceptableforverylargedatasets.

o LackofOWLconstructs:TheATMOntologyusesfewfeaturesfromOWLandtheclassescanmostlybeexpressedusingRDFS.However,theontologydoesincludetheuseofsomeOWLrestrictions.See,forexamplethedescriptionofsequences(gen:Sequence).Ingeneral,additionalOWLconstructscouldbeincorporatedintotheOntologytofurtherconstrainsemanticsandtoenableinferencestobedrawn.However,poorinferenceengineperformanceonlargedatasetslimittheeffectivenessofinferenceinthecontextofNASAdata.Thisisanareaforfurthercost/benefitanalysisandmoretestingandevaluation.

o Lackofconceptreusefromestablishedexternalontologies:TheATMOntologywasdevelopedwithoutreferencingclassesimportedfromexternally-developedontologies.Althoughthisrunscountertothespiritofontologyreuse,externally-definedclasseswerenottypicallyavailablefortheaviation-specificconceptsrequiredinthisOntologyorweredefinedinamannerthatdidnotmeetNASA’sapplicationrequirements.Noupperontologywasusedasascaffoldingforbuildingthisontology;ourassumption–correctormisinformed–wasthatanupperontologywouldaddcomplexitybutprovidelittlevalue-addedcontentorstructuretotheontology.Thisassumptionmustbecriticallyreexamined.

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AppendixE OrganizationofOntologyFiles

Tofacilitatereuse,ontologyfilesaredividedintobasemodelfilesandinstancefiles.Typically,thebasemodelfilescontainonlyclassesandsubclasses,withnoinstances;instancefilescontaininstancesonly.Occasionally,however,instancefileswillcontainclassesandsubclasses,especiallywhenthoseclasseshavebeenprogrammaticallygeneratedandmaynotbeofgeneralinterest.Thesecasesarenotedbelow.

Basemodelfilesareorganizedbynamespace(seeAppendixB).TheclassesassociatedwithagivennamespacearestoredinasingleOWLfileinTurtleformat(.ttl),withthefollowingfilenames:

• ATM.ttl:Allclassesdefinedfornamespaceprefixatm.• data.ttl:Allclassesdefinedfornamespaceprefixdata.• equipment.ttl:Allclassesdefinedfornamespaceprefixeqp.• general.ttl:Allclassesdefinedfornamespaceprefixgen.• NAS.ttl:Allclassesdefinedfornamespaceprefixnas.

Classinstancesarestoredinaseparatesetoffiles.Eachinstancefileimportsthebasemodelfilesinwhichthecorrespondingclassesaredefined.Theinstancefilesare:

• acInst.ttl:Containsaircraftinstancesassociatedwithprocessedflights.(eqp:Aircraft)• acManufInst.ttl:Containsaircraftmanufacturerinstances.(nas:AirframeManufacturer)• acModelInst.ttl:Containsinstancesofaircrafttypedesignators(eqp:AircraftType),aswellassubclassesof

eqp:AircraftModelandinstancesofthosesubclasses.BothaircraftmodelandtypearederivedfromtheCAST/ICAOAircraftTaxonomy.SeeSections5.4.3.1and5.4.3.2.Note:Thisisoneofonlyafew‘instancefiles’thatcontainssubclassesaswellasinstances.Typicallyallclassesandsubclassesaredefinedinabasemodelfile(seeabove).

• airlineInst.ttl:Containsinstancesofairlinecarriers(nas:AirCarrier).• airportInst.ttl:Containsinstancesofnas:Airport,nas:PhysicalRunway,nas:OperationalRunway,nas:Gate,

andgen:PointLocation,whichprovidestheairportcoordinates.Inaddition,thisfilecontainssubclassesofnas:Gate,nas:PhysicalRunway,andnas:OperationalRunwaythatareairport-specific.SeesubclassesdiscussioninSection6.86.96.10.Note:Thisisoneofonlyafew‘instancefiles’thatcontainssubclassesaswellasinstances.Typicallyallclassesandsubclassesaredefinedinabasemodelfile(seeabove).

• allInst.ttl:Thisfilecanbeusedtoloadtheentireontology,becauseitimportsallinstancefiles.• ARTCCLocationInst.ttl:Containsinstancesofnas:ARTCC,plusinstancesofgen:Polygonal2DRegion,

representingtheboundariesofeachARTCC(includinggen:PointLocationinstancesspecifyingthepointsthatdefinethepolygonboundary).

• ASPMinst.ttl:ContainsairportweatherinstancesgeneratedfromtheASPMdatabase,includinginstancesofdata:ASPMmeteorologicalConditionandassociatedinstancesofvarioussky,wind,visibility,andweatherconditions.

• dayInst.ttl:Containsinstancesofalldaysfrom2012-2017.• equipmentInst.ttl:Containsinstancesofeqp:EngineType,eqp:AircraftWakeCategory,and

eqp:AircraftWeightClass.• fixInst.ttl:Containsinstancescorrespondingtoallnamedfixes(allsubclassesofatm:NavigationFix).These

fixesweregeneratedfromFAA’sERAMdata,whichincludesacomprehensivelistingofnavigationfixes.• flightInst.ttl:Containsinstancesof100flightsduringJuly2014eitherarrivingordepartingNewYorkarea

airportsJFK,EWR,andLGA.Includesinstancesofactualflightsandplannedflightpaths,plusassociated

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flightplans(includingtheplannedroutes,fixes,andSID/STARtraverses)andactualtrackpoints(includingtheassociatedfixesandsectorsthroughwhichtheflightspassed).

• METARinst.ttl:ContainsinstancesofallMETARreports(data:METARreport)issuedatJFK,EWR,andLGAduringJuly2014,plusalloftheassociatedinstances(data:SkyCondition,data:SurfaceWindCondition,data:VisibilityCondition,data:WeatherCondition,data:CloudLayerProfile,data:CloudLayer,nas:RunwayVisibleRangeMeasurement).

• NASinst.ttl:ContainsaninstancerepresentingtheFAAcommandcenter(ATCSCC)plusARTCCinstancescoveringtheentireNASandthesetofNAShourinstancesrepresentingeachhourinaday.

• routeInst.ttl:ContainsinstancesofdefinedFAAairspaceroutes(nas:AirspaceRouteanditsvarioussubclasses)plusthecorrespondinginstancesofatm:NavElementContainerthatsequencethenavigationalelementscomprisingeachroute.

• SectorLocationInst.ttl:Containsinstancesofnas:Sector,plusinstancesofgen:ShearSidedPolygonalVolume,representingthevolumeofeachairspacelayerthatcomprisesthesectors(includinggen:PointLocationinstancesspecifyingthepointsthatdefinethepolygonboundaryforeachlayer).See2.3.

• sidStarInst.ttl:ContainsinstancesofSIDsandSTARs,alongwithinstancesofthevariousroutesthroughthem(atm:SIDSTARroute)plusthecorrespondinginstancesofatm:NavElementContainerthatsequencethenavigationalelementscomprisingeachroute.

• TAFinst.ttl:ContainsinstancesofallTAFweatherforcasts(data:TAFreport)issuedatJFK,EWR,andLGAduringJuly2014,plusalloftheirassociatedinstances(data:TAFmeteorologicalCondition,data:SkyCondition,data:SurfaceWindCondition,data:VisibilityCondition,data:WeatherCondition,data:CloudLayerProfile,data:CloudLayer).

• TMIinst.ttl:ContainsinstancesofallGroundDelay,GroundStop,andReRoutetrafficmanagementinitiativesissuedduringJuly2014.Includedareauxiliaryinstancesdescribingflightandairportconstraints(atm:FlightSpec,atm:AirportSpec).AlsoincludedaretheroutesegmentspermittedforeachReRouteTMIandalltheassociatedinstancesnecessaryfordefiningthoseroutesegments.SeeSection4.

• TRACONinst.ttl:ContainsinstancesofallTRACONs(nas:TRACON).

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AppendixF Acronyms

Acronym AcronymExpansionADL AggregateDemandListARTCC AirRouteTrafficControlCenter(or"Center")ASPM AviationSystemPerformanceMetricsATCSCC AirTrafficControlSystemCommandCenterATCT AirTrafficControlTowerATM AirTrafficManagementCDR CodedDepartureRouteCONUS ContinentalUSDAS DelayAssignmentEDCT EstimatedDepartureClearanceTimeERAM En-RouteAutomationModernizationETA EstimatedTimeofArrivalETD EstimatedTimeofDepartureETMS EnhancedTrafficManagementSystemFAA FederalAviationAdministrationFCA Flow-ControlledAreaGAAP GeneralAviationAirportProgramGDP GroundDelayProgramGMT GreenwichMeanTimeGS GroundStopIEC InternationalElectrotechnicalCommissionISO InternationalStandardsOrganizationLOA LetterofAgreementMETAR MeteorologicalTerminalAviationRoutineWeatherReportMIT Miles-in-TrailNAS NationalAirspaceSystemNASA NationalAeronauticsandSpaceAdministrationOAG OfficialAirlineGuidePAR ProgramArrivalRateRVR RunwayVisibleRangeSID StandardInstrumentDepartureSTAR StandardTerminalArrivalRouteTAF TerminalAerodromeForecastTFMS TrafficFlowManagementSystemTMI TrafficManagementInitiative

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TRACON TerminalRadarApproachControlUDP UnifiedDelayProgramUTC CoordinatedUniversalTimeor"ZULU"TimeVOR Very-highFrequencyOmniDirectionalRadioRangeWITI WeatherImpactedTrafficIndexWMO WorldMeteorologicalOrganization

The NASA Air Traffic Management Ontology

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