ICAO Policy on GNSS, GNSS Sarps and Global GNSS Developments

ICAO policy on GNSS, GNSS SARPs and global GNSS developments

JimJim NagleNagle Chief,Chief, Communication,Communication, NavigationNavigation andand SurveillanceSurveillance SectionSection ICAOICAO Presentation overview

44 IntroductionIntroduction 44 GNSSGNSS developmentsdevelopments inin ICAOICAO 44 ICAOICAO policypolicy onon GNSSGNSS 44 BasicBasic technicaltechnical principlesprinciples 44 GNSSGNSS elementselements 44 GNSSGNSS performanceperformance requirementsrequirements 44 FutureFuture evolutionevolution 44 GNSSGNSS implementationimplementation inin StatesStates 44 GNSSGNSS andand PBNPBN Introduction - ICAO

44ConventionConvention (Chicago,(Chicago, 1944)1944) andand AnnexesAnnexes 44UNUN SpecializedSpecialized AgencyAgency 44190190 ContractingContracting StatesStates 44AssemblyAssembly (ordinarily(ordinarily everyevery 33 years)years) 44CouncilCouncil –– 3636 StatesStates 44AirAir NavigationNavigation CommissionCommission –– 1919 membersmembers 44AirAir NavigationNavigation BureauBureau 44Standards,Standards, RecommendedRecommended PracticesPractices (SARPs)(SARPs) Introduction - ICAO

ICAO HQ

Paris

Dakar Cairo Mexico Bangkok Nairobi Lima Introduction – GNSS

44 TheThe theoreticaltheoretical definitiondefinition:: ¾¾ ““GNSSGNSS.. AA worldwideworldwide positionposition andand timetime determinationdetermination systemsystem thatthat includesincludes oneone oror moremore sasatellitetellite constellations,constellations, aircraftaircraft receiversreceivers andand systemsystem integrityintegrity monitoring,monitoring, augmentedaugmented asas necessarynecessary toto supportsupport thethe requrequiredired navigationnavigation performanceperformance forfor thethe intendedintended operation.operation.”” [from[from ICAOICAO AnnexAnnex 10,10, VolumeVolume I]I]

44 TheThe practicalpractical foundationfoundation:: ¾¾ 1994/1996:1994/1996: USUS andand RussiaRussia offeroffer toto ICAOICAO toto provideprovide GPSGPS (Global(Global Positioning System)/GLONASS ((GLObalGLObal NAvigation NAvigation SatelliteSatellite System)System) serviceservice forfor thethe foreseeableforeseeable futurefuture onon aa continuouscontinuous worldwideworldwide basisbasis andand freefree ofof directdirect useruser feesfees GNSS developments in ICAO

44 19911991:: 10th10th AirAir NavigationNavigation Conference:Conference: ¾¾ TheThe AirAir NavigationNavigation CommissionCommission requestsrequests thethe initiationinitiation ofof anan agreagreementement betweenbetween ICAOICAO andand GNSSGNSS-provider-provider States concerning qualityquality andand durationduration ofof GNSSGNSS 44 19931993:: ICAOICAO GNSSGNSS PanelPanel establishedestablished ¾¾ PrimaryPrimary task:task: toto developdevelop SARPsSARPs inin supportsupport ofof aeronauticalaeronautical applicapplicationsations ofof GNSSGNSS 44 1994/19961994/1996:: GPS/GLONASSGPS/GLONASS offersoffers fromfrom US/RussiaUS/Russia 44 19991999:: GNSSPGNSSP completescompletes thethe developmentdevelopment ofof GNSSGNSS SARPSSARPS (applicable(applicable 2001)2001) 44 20022002 ––today today:: GNSSPGNSSP (subsequently(subsequently renamedrenamed NSP)NSP) developsdevelops GNSSGNSS SARPsSARPs enhancementsenhancements 44 20032003:: 11th11th AirAir NavigationNavigation Conference:Conference: ¾¾ TheThe ConferenceConference recommendsrecommends aa worldwideworldwide transitiontransition toto GNSSGNSS-based-based air navigationnavigation ICAO policy on GNSS

44 19941994:: StatementStatement ofof ICAOICAO policypolicy onon CNS/ATMCNS/ATM systemssystems implementationimplementation andand operationoperation approvedapproved byby thethe ICAOICAO Council:Council: ¾¾ ““GNSSGNSS shouldshould bebe implementedimplemented asas anan evolutionaryevolutionary progressionprogression fromfrom existingexisting globalglobal navigationnavigation satellitsatellitee systems,systems, including the UnitUniteded StatesStates’’ GPSGPS andand the Russian FederationFederation’s’s GLONASS, towards an integrated GNSSGNSS overover whichwhich ContractingContracting StatesStates exerciseexercise aa sufficientsufficient levellevel ccontrolontrol onon aspectsaspects relatedrelated to its use by civil aviation. ICAO shall contcontinueinue to explore,explore, inin consultationconsultation withwith ContractingContracting States,States, airspaceairspace usersusersand serviceservice providers,providers, thethe feasibilityfeasibility ofof achievingachieving aa civil,civil, internainternationallytionally controlledcontrolled GNSSGNSS”” 44 19981998:: AssemblyAssembly resolutionsresolutions A32A32-19-19 ((“Charter“Charter on the Rights and ObligationsObligations ofof StatesStates RelatingRelating toto GNSSGNSS ServicesServices”)”) and A32A32-20-20 ((“Development“Development andand elaborationelaboration ofof anan appropriateappropriate longlong-term-term legal framework toto governgovern thethe implementationimplementation ofof GNSSGNSS”)”) The GPS/GLONASS offers

44 GPSGPS offeroffer (1994):(1994): ¾¾ GPSGPS standardstandard positioningpositioning servserviceice toto bebe mademade availableavailable onon aa continuouscontinuous worldwideworldwide basisbasis andand freefree ofof directdirect useruser feesfees forfor thethe foreseeableforeseeable future.future. AtAt leastleast 66 yearsyears noticenotice priorprior toto termination.termination. 44 GLONASSGLONASS offeroffer (1996):(1996): ¾¾ GLONASSGLONASS standardstandard accuracyaccuracy cchannelhannel toto bebe providedprovided toto thethe worldwideworldwide aviationaviation communitycommunity forfor aa periodperiod ofof atat leastleast 1515 yearsyears withwith nono directdirect chargescharges collectedcollected fromfrom users.users. 44 BothBoth offersoffers acceptedaccepted byby ICAOICAO CouncilCouncil 44 OffersOffers reiteratedreiterated atat variousvarious ooccasions,ccasions, mostmost recentlyrecently FebruaryFebruary 20072007 (180th(180th SessionSession ofof thethe ICAOICAO Council)Council) GNSS elements: GPS

44 NominalNominal constellation:constellation: 2424 satellitsatelliteses (30(30 activeactive asas ofof MarchMarch 2007)2007) 44 SixSix orbitalorbital planesplanes 44 NearNear-circular,-circular, 20,20020,200 kmkm altitudealtitude (26,600(26,600 kmkm radius)radius) 1212-hour-hour orbitsorbits 44 FirstFirst experimentalexperimental satellitesatellite llaunchedaunched inin 1978,1978, operationaloperational inin 19951995 44 ManagedManaged byby thethe USUS NationalNational SpaceSpace-Based-Based Positioning, Navigation,Navigation, andand TimingTiming (PNT)(PNT) ExecutiveExecutive CommitteeCommittee 4 Standard positioning service (SPS) frequency: 1 575.42 MHz 4 Selective availability (SA) discontinued in 2000 4 ICAO Annex 10, Volume I, section 3.7.3.1 GNSS elements: GLONASS

44 NominalNominal constellation:constellation: 2424 satellsatellitesites (fewer(fewer activeactive asas ofof AugustAugust 2007)2007) 44 ThreeThree orbitalorbital planesplanes 44 NearNear-circular,-circular, 19,10019,100 kmkm altitudealtitude (25,500(25,500 radius)radius) 11:1511:15-hour-hour orbitsorbits 44 FirstFirst experimentalexperimental satellitesatellite llaunchedaunched inin 1982,1982, operationaloperational inin 1995,1995, subsequentsubsequent declinedecline (plans(plans toto restorerestore fullfull operationaloperational capabilitycapability byby 2010)2010) 44 OperatedOperated byby thethe MinistryMinistry ofof DefenceDefence ofof thethe RussianRussian FederationFederation 44 ChannelChannel ofof standardstandard accuracyaccuracy (CSA) frequencies: 1602 MHz ±±0.5625 0.5625nn MHzMHz 4 ICAO Annex 10, Volume I, section 3.7.3.2 GNSS elements: augmentation systems

44 ThreeThree ICAOICAO GNSSGNSS augmentationaugmentation systems:systems: ¾¾aircraftaircraft-based-based augmentation system (ABAS) ¾¾satellitesatellite-based-based augmentation systemsystem (SBAS)(SBAS) ¾¾groundground-based-based augmentation system (GBAS)(GBAS) >ground>ground-based-based regionalregional augmentationaugmentation systemsystem (GRAS)(GRAS) 44 Purpose:Purpose: toto overcomeovercome inherentinherent limitationslimitations inin thethe serviceservice providedprovided byby thethe corecore constellationsconstellations GNSS elements: ABAS

44 ABAS:ABAS: aircraftaircraft-based-based augmentationaugmentation systemsystem 44 TheThe basicbasic elementelement ofof ICAOICAO GNSSGNSS 44 Purpose:Purpose: toto augment/integrateaugment/integrate GNSSGNSS informationinformation withwith onon-board-board aircraftaircraft informationinformation 44 RequiredRequired toto ensureensure thatthat performanceperformance meetsmeets AnnexAnnex 1010 requirementsrequirements (Volume(Volume I,I, TableTable 3.7.2.43.7.2.4-1)-1) 44 UsesUses redundantredundant satellitesatellite rangerange measurementsmeasurements (and/or(and/or barometricbarometric information)information) toto detectdetect faultyfaulty signalssignals andand alertalert thethe pilotpilot 44 ReceiverReceiver-autonomous-autonomous integrity monitoringmonitoring (RAIM)(RAIM) ––five five satellitessatellites requiredrequired (or(or fourfour ++ baro)baro) 44 FaultFault detectiondetection andand exclusionexclusion (FDE)(FDE) ––six six satellitessatellites requiredrequired (or five ++ baro)baro) 44 RAIM/FDERAIM/FDE availability:availability: areare sufficientsufficient redundantredundant measurementsmeasurements available?available? 44 ICAOICAO AnnexAnnex 10,10, VolumeVolume I,I, sectionsection 3.7.3.33.7.3.3 GNSS elements: SBAS (1)

44 SBAS:SBAS: satellitesatellite-based-based augmentationaugmentation systemsystem 44 AugmentsAugments corecore satellitesatellite constellationsconstellations byby providingproviding ranging,ranging, intintegrityegrity and correctioncorrection informationinformation 44 TheThe informationinformation isis broadcastbroadcast viavia geostationarygeostationary satellites,satellites, inin ththee same band asas thethe corecore constellationsconstellations 44 SBASSBAS elements:elements: ¾¾ aa networknetwork ofof groundground referencereference stationsstations thatthat monitormonitor satellitesatellite sisignalsgnals ¾¾ mastermaster stationsstations processingprocessing referencereference stationsstations datadata andand generatingeneratingg SBASSBAS signalssignals ¾¾ uplinkuplink stationsstations toto sendsend thethe messagesmessages toto thethe geostationarygeostationary satellsatellitesites ¾¾ transponderstransponders onon thethe satellitessatellites toto broadcastbroadcast SBASSBAS messagesmessages 44 SBASSBAS (where(where supported)supported) providesprovides higherhigher availabilityavailability ofof GNSSGNSS servservicesices and lowerlower minimaminima thanthan ABASABAS 44 ApproachApproach proceduresprocedures withwith verticalvertical guidanceguidance (APV(APV-I-I and --II)II) 44 DevelopmentsDevelopments toto achieveachieve CatCat-I-like-I-like minimaminima areare underway 44 ICAOICAO AnnexAnnex 10,10, VolumeVolume I,I, sectionsection 3.7.3.43.7.3.4 GNSS elements: SBAS (2)

44 WideWide AreaArea AugmentationAugmentation SystemSystem ((WAASWAAS)) --commissioned commissioned forfor safetysafety-of-life-of-life useuse inin 20032003 44 EuropeanEuropean GeostationaryGeostationary NavigationNavigation OverlayOverlay ServiceService ((EGNOSEGNOS)) -- initialinitial operationsoperations startedstarted inin 20052005 44 MultiMulti-functional-functional Transport SatelliteSatellite (MTSAT)(MTSAT) SatelliteSatellite-based-based AugmentationAugmentation SystemSystem ((MSASMSAS)) --satellites satellites launched in 20052005-2006-2006 44 GPSGPS aidedaided GeostationaryGeostationary EarthEarth OrbitOrbit (GEO)(GEO) AugmentedAugmented NavigationNavigation ((GAGANGAGAN)) --to to bebe completed in 2008 44 SBASSBAS coveragecoverage areaarea vsvs serviceservice area:area: ¾¾ SBASSBAS coveragecoverage area:area: GEOGEO satellitesatellite signalsignal footprintfootprint ¾¾ SBASSBAS serviceservice area:area: serviceservice areaarea establishedestablished byby aa StateState withinwithin SBASSBAS coveragecoverage areaarea GNSS elements: GBAS/GRAS

44 GBAS:GBAS: groundground-based-based augmentationaugmentation systemsystem 44 OperatesOperates inin thethe VHFVHF NAVNAV bandband (108(108 – 117.975 MHz) 44 SupportsSupports precisionprecision approachapproach serviceservice (currently(currently upup toto CATCAT I)I) andand optionallyoptionally positioningpositioning serviceservice 44 PrecisionPrecision approachapproach serviceservice providesprovides ““ILS-like”ILS-like” deviation guidance forfor finalfinal approachapproach segmentssegments 44 CanCan supportsupport multiplemultiple runwaysrunways 44 GRAS:GRAS: groundground-based-based regionalregional augmentationaugmentation systemsystem ¾¾ anan extensionextension ofof GBASGBAS toto provideprovide regionalregional coveragecoverage downdown toto APVAPV serviceservice 44 ICAOICAO AnnexAnnex 10,10, VolumeVolume I,I, sectionsection 3.7.3.53.7.3.5 GNSS signal-in-space performance requirements

44 AccuracyAccuracy ––The The differencedifference betweenbetween thethe estimatedestimated andand actualactual aircraftaircraft positionposition 44 IntegrityIntegrity ––A A measuremeasure ofof thethe trusttrust whichwhich cancan bebe placedplaced inin thethe correctnesscorrectness ofof thethe informationinformation suppliedsupplied byby thethe totaltotal system.system. ItIt includesincludes thethe abilityability ofof thethe systemsystem toto alertalert thethe useruser whenwhen thethe sysystemstem shouldshould notnot bebe usedused forfor thethe intendedintended operationoperation (alert)(alert) withinwithin aa prescribedprescribed timetime periodperiod (time(time-to-alert)-to-alert) 44 ContinuityContinuity ––The The capabilitycapability ofof thethe systemsystem toto performperform itsits functionfunction withoutwithout unscheduledunscheduled interruptionsinterruptions duringduring thethe intendedintended operationoperation 44 AvailabilityAvailability ––The The portionportion ofof timetime duringduring whichwhich thethe systemsystem isis simultaneouslysimultaneously deliveringdelivering thethe requiredrequired accuracy,accuracy, integrityintegrity andand continuitycontinuity GNSS signal-in-space performance requirements (Annex 10, Vol.I)

Accuracy Accuracy horizontal vertical 95% 95% Integrity Time-to-alert Continuity Typical operation Availability

En-route 3.7 km N/A 1 – 1 × 10–7/h 5 min 1 – 1 × 10–4/h 0.99 to (2.0 NM) to 1 – 1 × 10–8/h 0.99999

En-route, 0.74 km N/A 1 – 1 × 10–7/h 15 s 1 – 1 × 10–4/h 0.99 to Terminal (0.4 NM) to 1 – 1 × 108/h 0.99999

Initial approach, 220 m N/A 1 – 1 × 10–7/h 10 s 1 – 1 × 10–4/h 0.99 to Intermediate approach, (720 ft) to 1 – 1 × 10–8/h 0.99999 Non-precision approach (NPA), Departure

Approach operations with 16.0 m 20 m 1 – 2 × 10–7 10 s 1 – 8 × 10–6 0.99 to vertical guidance (APV-I) (52 ft) (66 ft) per in any 15 s 0.99999 approach

Approach operations with 16.0 m 8.0 m 1 – 2 × 10–7 6 s 1 – 8 × 10–6 0.99 to vertical guidance (APV-II) (52 ft) (26 ft) per in any 15 s 0.99999 approach

Category I precision approach 16.0 m 6.0 m to 4.0 m 1 – 2 × 10–7 6 s 1 – 8 × 10–6 0.99 to (52 ft) (20 ft to 13 ft) per in any 15 s 0.99999 approach Future evolution

44GPSGPS andand GLONASSGLONASS evolutionevolution (GPS(GPS L5/L5/ GLONASSGLONASS L3L3 signals)signals) 44GalileoGalileo 44GBASGBAS supportsupport ofof CatCat II/IIIII/III landinglanding operationsoperations GNSS implementation in States

44 ElementsElements toto bebe addressedaddressed foforr aa StateState implementingimplementing GNSSGNSS operationsoperations:: ¾¾ planningplanning andand organizationorganization ¾¾ procedureprocedure developmentdevelopment ¾¾ airspaceairspace considerationsconsiderations ¾¾ aeronauticalaeronautical informationinformation servicesservices ¾¾ systemsystem safetysafety analysisanalysis ¾¾ certificationcertification andand operationaloperational approvalsapprovals ¾¾ anomaly/interferenceanomaly/interference reportingreporting ¾¾ vulnerabilityvulnerability Implementation planning

44 PlanningPlanning toto bebe coordinatedcoordinated onon aa regionalregional // widewide areaarea basisbasis (common(common requirements)requirements) 44 CoordinationCoordination throughthrough ICAO and its regional bodies ((PIRGs)PIRGs) 44 Bilateral/multilateralBilateral/multilateral coordinationcoordination asas necessarynecessary 44 EstablishEstablish aa GNSSGNSS implementatiimplementationon team,team, involvinginvolving usersusers andand appropriateappropriate multidisciplinarymultidisciplinary expertiseexpertise 44 SampleSample teamteam TermsTerms ofof Reference:Reference: ICAOICAO GNSSGNSS ManualManual (Doc(Doc 9849)9849) AppendixAppendix CC 44 GNSSGNSS planplan toto includeinclude thethe developmentdevelopment ofof aa businessbusiness casecase 44 TrainingTraining requirementsrequirements Procedures development

44 ICAOICAO PANSPANS-OPS-OPS (Doc 8168) containscontains thethe designdesign criteriacriteria for GNSSGNSS proceduresprocedures 44 Departure,Departure, arrival,arrival, approachapproach proceduresprocedures usingusing ““basicbasic GNSSGNSS”” receiverreceiver (ABAS)(ABAS) and/orand/or SBAS/GBASSBAS/GBAS receiverreceiver 44 IncludesIncludes proceduresprocedures forfor ““APV”APV” (approach (approach procedure with verticalvertical guidance):guidance): ¾¾ APV/BaroAPV/Baro-VNAV-VNAV ¾ APV with SBAS (LPV: localizer performance with vertical guidance) Airspace considerations

44 AccurateAccurate navigation in oceanicoceanic enen-route-route airspaceairspace (no(no conventionalconventional navaidsnavaids available)available) 44 LateralLateral separationseparation reductionsreductions enabledenabled byby ADSADS (GNSS(GNSS-based)-based) inin nonnon-radar-radar airspace 44 ContinentalContinental enen-route-route and terminal airspace:airspace: RNAVRNAV arrivalarrival andand departuredeparture proceduresprocedures reducereduce delaysdelays andand lessless workloadworkload 44 Terminal,Terminal, approach/departureapproach/departure airspace:airspace: supportsupport toto aerodromesaerodromes notnot servedserved adequatelyadequately byby conventionalconventional navaidsnavaids Aeronautical information services

44 StateState’s’s AeronauticalAeronautical informationinformation publicationpublication (AIP)(AIP) toto covercover thesethese aspects:aspects: ¾¾DescriptionDescription ofof GNSSGNSS servicesservices ¾¾InformationInformation aboutabout thethe approvalapproval ofof GNSSGNSS-based-based operationsoperations ¾¾WorldWorld GeodeticGeodetic SystemSystem ––1984 1984 (WGS(WGS-84)-84) coordinatecoordinate systemsystem ¾¾AirborneAirborne navigationnavigation databasedatabase ¾¾StatusStatus monitoringmonitoring andand NOTAMNOTAM WGS-84

44 CoordinateCoordinate systemsystem adoptedadopted byby ICAOICAO toto bebe usedused inin supportsupport ofof GNSSGNSS 44 ICAOICAO AnnexAnnex 4,4, 11,11, 1414 andand 1515 44 UsingUsing differentdifferent coordinatecoordinate systemssystems isis aa hazardhazard 44 TransitionTransition pathpath toto WGSWGS-84:-84: ¾¾mathematicalmathematical transformationtransformation ofof existingexisting coordinatecoordinate ¾¾resurveyresurvey (preferred(preferred option)option) Airborne navigation database

44 SafetySafety ofof GNSSGNSS navigationnavigation dependsdepends onon thethe integrityintegrity ofof thethe datadata inin thethe airborneairborne navigationnavigation databasedatabase 44 DataData originatesoriginates withwith StatesStates 44 QualityQuality ofof thethe positionposition datadata mustmust bebe retainedretained throughoutthroughout thethe datadata chainchain 44 ManualManual entryentry intointo thethe airborneairborne databasedatabase notnot permittedpermitted 44 EUROCAE/RTCAEUROCAE/RTCA standardsstandards (DO(DO-200A/ED-76-200A/ED-76 and DODO-201A/ED77)-201A/ED77) Status monitoring

44 WithWith conventionalconventional navaids,navaids, groundground equipmentequipment statusstatus mapsmaps directlydirectly toto serviceservice availability:availability: ¾¾ ILSILS isis downdown -->> precision approach service is not available 44 WithWith GNSS,GNSS, mappingmapping ofof individualindividual satellitesatellite statusstatus toto serviceservice availabilityavailability isis notnot direct:direct: ¾¾ GPSGPS satellitesatellite x isis downdown -->> impact on GPS service depends on useruser location,location, time,time, equipmentequipment characteristicscharacteristics andand configurationconfiguration 44 RealReal-time-time groundground-based-based monitoring of GNSS service is in general notnot aa requirement:requirement: ¾¾ PrimaryPrimary responsibilityresponsibility forfor basicbasic GNSSGNSS statusstatus monitoringmonitoring residesresides inin thethe avionicsavionics (RAIM:(RAIM: ReceiverReceiver AutonomousAutonomous IntegrityIntegrity Monitoring)Monitoring) 44 RAIMRAIM availabilityavailability predictionprediction obtainedobtained asas partpart ofof flightflight planningplanning(from GNSSGNSS avionicsavionics interface,interface, externalexternal software,software, websitewebsite…)…) GNSS NOTAM

44 GNSSGNSS NOTAMNOTAM provideprovide informationinformation on:on: ¾¾ IndividualIndividual satellitesatellite outagesoutages oror temporarytemporary unavailabilityunavailability ofof serviceservice duedue toto testingtesting oror anomaliesanomalies ¾¾ Example:Example: GPSGPS NOTAMNOTAM (location(location indicatorindicator KNMH,KNMH, U.S.U.S. CoastCoast GuardGuard NavigationNavigation SystemSystem Centre)CentreCentre)) suppliedsupplied byby constellationconstellation operatoperatoror asas internationalinternational NOTAMNOTAM ¾¾ ServiceService outagesoutages atat specificspecific airports/airspacesairports/airspaces ¾¾ Example:Example: SBASSBAS NOTAMNOTAM derivedderived frfromom serviceservice volumevolume modelmodel softwaresoftware suppliedsupplied byby SBASSBAS operatoroperator 44 NOTAMNOTAM requirementsrequirements cancan vavaryry dependingdepending onon practicalpractical considerationsconsiderations (e.g.(e.g. availabiliavailabilityty ofof conventionalconventional navaidsnavaids asas backback-up)-up) System safety assessment

44AnnexAnnex 11:11: safetysafety assessmentassessment beforebefore makingmaking significantsignificant safetysafety-relatedsafety--relatedrelated changeschanges toto ATCATC systemsystem 44SystematicSystematic analysisanalysis ofof hazardshazards andand mitigationsmitigations duringduring allall phasesphases ofof systemsystem’ssystem’’ss lifelife cyclecycle ¾¾GNSSGNSS safetysafety planplan Certification and operational approvals

44 StateState responsibilityresponsibility toto authorizeauthorize GNSSGNSS operationsoperations inin itsits airspaceairspace 44 ApprovalApproval document:document: forfor aircraftaircraft withwith certifiedcertified equipmentequipment andand approvedapproved flightflight manualmanual 44 SpecifiesSpecifies anyany limitationslimitations onon proposedproposed operationsoperations 44 VFRVFR useuse oror IFRIFR useuse 44 GNSSGNSS alonealone oror withwith otherother systemssystems 44 AirworthinessAirworthiness certificationcertification basedbased onon RTCA/EUROCAERTCA/EUROCAE documentsdocuments Anomaly reporting

44 Anomaly:Anomaly: GNSSGNSS serviceservice outageoutage (may(may bebe duedue toto interference)interference) 44 PilotPilot toto reportreport toto ATCATC asapasaprequesting requesting specialspecial handlinghandling asas requiredrequired andand filefile completecomplete reportreport inin accordanceaccordance withwith StateState proceduresprocedures 44 ControllersControllers toto recordrecord informationinformation ofof thethe occurrence,occurrence, toto identifyidentify otherother GNSSGNSS-equipped-equipped aircraftaircraft that may bebe affected,affected, andand toto forwardforward informationinformation toto designateddesignated authorityauthority 44 NationalNational focalfocal point unit to collect anomalyanomaly-related-related informationinformation Vulnerability

44 PotentialPotential forfor interferenceinterference isis thethe mainmain vulnerabilityvulnerability 44 ReceiverReceiver interferenceinterference maskmask specifiesspecifies thethe levellevel ofof interferenceinterference tthathat can bebe toleratedtolerated 44 SeveralSeveral interferenceinterference sourcessources ((eg.eg. microwavemicrowave links within L1 band in somesome States)States) 44 UnintentionalUnintentional vsvsintentional intentional interferenceinterference 44 StatesStates should:should: ¾¾ assessassess sourcessources of vulnerability and develop mitigations (technic(technical,al, proceduralprocedural backback-up)-up) ¾¾ provideprovide effectiveeffective spectrumspectrum managementmanagement andand protectionprotection ofof GNSSGNSS frequenciesfrequencies toto reducereduce thethe possibilitypossibility ofof unintentionalunintentional interfereinterferencence ¾¾ useuse onon-board-board mitigationmitigation techniquestechniques ((egeg inertial) ¾¾ considerconsider selectiveselective retentionretention ofof conventionalconventional navaidsnavaids asas partpart ofof an evolutionaryevolutionary transitiontransition ¾¾ taketake fullfull advantageadvantage ofof newnew GNSSGNSS signalssignals andand constellationsconstellations GNSS and Performance Based Navigation

ALLALL PBNPBN NavigationNavigation specificationsspecifications areare basedbased onon GNSSGNSS eithereither asas thethe primaryprimary navigationnavigation infrastructureinfrastructure oror asas oneone elementelement ofof thethe infrastructureinfrastructure END

ThankThank youyou forfor youryour attention!attention! Background Basic technical principles (1)

44 TheThe aircraftaircraft computescomputes itsits positionposition byby ““trilateration”trilateration” 44 AA simplifiedsimplified geometricalgeometrical explanation:explanation: ¾¾thethe aircraftaircraft computescomputes distancesdistances d1,d1, d2d2 andand d3d3 fromfrom threethree satellitessatellites whosewhose positionspositions P1,P1, P2P2 andand P3P3 areareknown; known; ¾¾knowingknowing distancesdistances from,from, andand positionspositions of,of, threethree satellites,satellites, itit isis aa simplesimple geometricalgeometrical problemproblem toto derivederive thethe positionposition ofof thethe aircraft:aircraft: ¾¾ thethe positionposition ofof thethe aircraftaircraft isis thethe intersectionintersection ofof thethe threethree spheresspheres ofof radiusradius d1,d1, d2d2 andand d3d3 andand centrescentres respectivelyrespectively P1,P1, P2P2 andand P3P3 ¾¾ (there(there areare actuallyactually twotwo intersectionintersection points,points, butbut typicallytypically onlyonly oneone ofof themthem isis ““reasonable”)reasonable”) Basic technical principles (2)

44 HowHow doesdoes thethe aircraftaircraft knowknow thethe positionposition ofof thethe satellites?satellites? ¾¾ thethe satellitesatellite positionposition informationinformation isis broadcastbroadcast byby thethe satellitesatellitess themselvesthemselves asas aa partpart ofof thethe navigationnavigation messagemessage transmittedtransmitted byby eacheach satellitesatellite 44 HowHow doesdoes thethe aircraftaircraft computecompute itsits distancedistance fromfrom thethe satellites?satellites? ¾¾ messagesmessages sentsent byby thethe satellitessatellites areare timetime-tagged-tagged with the time of transmission;transmission; ¾¾ byby comparingcomparing thethe timetime thethe messagemessage isis receivedreceived andand thethe timetime thethe messagemessage waswas sent,sent, thethe aircraftaircraft cancan measuremeasure thethe timetime takentaken byby thethe messagemessage toto traveltravel fromfrom thethe satellitesatellite toto thethe aircraft;aircraft; ¾¾ knowingknowing thethe speedspeed atat whichwhich memessagesssages traveltravel (the(the speedspeed ofof light),light), andand thethe timetime taken,taken, thethe aircraftaircraft cancan computecompute thethe distancdistancee travelledtravelled byby thethe messagemessage (or(or “rangerange””),), asas follows:follows: ¾¾ speedspeed == distance/tidistance/time,me, hencehence >> distance=distance= speedspeed xx timetime Basic technical principles (3)

44 SomeSome complicationscomplications:: ¾¾ thethe simplifiedsimplified geometrical explanatexplanatiionon assumes thatthat timetime referenreferencece usedused byby thethe satellitessatellites andand byby thethe aircraftaircraft areare thethe samesame ¾¾ however,however, thisthis isis notnot thethe casecase – the satellites carry ““precise”precise” clocks (atomic(atomic clocks),clocks), whereaswhereas thethe aircraftaircraft typicallytypically carriescarries aa relatirelativelyvely impreciseimprecise (and(and lessless expensive)expensive) quartzquartz clockclock ¾¾ hence,hence, thethe ““range”range” computed by the aircraft based on the equation shownshown aboveabove isis notnot thethe ““true”true” range – it isis a “pseudorangepseudorange”” ¾¾ Example:Example: aa 1 µµss (microsecond) synchronizationsynchronization error betweenbetween clocks correspondscorrespondsto aa 300300 mm errorerror inin rangerange measurementmeasurement ¾¾ Solution:Solution: thethe clockclock errorerror isis resolvedresolved byby usingusing aa fourthfourth additionadditionalal satellitesatellite toto provideprovide additionaladditional informationinformation toto estimateestimate aircraftaircraftclock error andand thusthus derivederive ““truetrue rangerange”” information ¾¾ InsteadInstead ofof threethree equationsequations inin threethree unknownsunknowns (the(the threethree positionposition coordinatescoordinates ofof thethe aircraft),aircraft), thethe aircraftaircraft receiverreceiver solvessolves fourfour equations inin fourfour unknownsunknowns (the(the threethree positionposition coordinatescoordinates andand thethe clockclock eerror)rror) GNSS signal-in-space performance requirements (Annex 10, Vol.I)

Typical operation Horizontal alert limit Vertical alert limit

En-route (oceanic/continental 7.4 km N/A low density) (4 NM) En-route (continental) 3.7 km N/A (2 NM) En-route, 1.85 km N/A Terminal (1 NM) NPA 556 m N/A (0.3 NM) APV-I 40 m 50 m (130 ft) (164 ft) APV- II 40.0 m 20.0 m (130 ft) (66 ft) Category I precision approach 40.0 m 15.0 m to 10.0 m (130 ft) (50 ft to 33 ft)