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IMPORTANTTheAbstractscontainedinthisBookofAbstractsarethePreliminaryabstractssuppliedbytheauthorsandareonlyprovidedtoassistyouwithchoosingthepresentationsyouwishtoattendattheSymposium.
AbstractTitlesand/ortextmayhavechangedslightlyandifsowillbeincludedwiththefinalpapersintheSymposiumProceedings.
PleaseselectthepresentationsyouwishtoattendpriortoattendingthesymposiumastheBookofAbstractswillnotbeprovidedasahandoutandwillonlybeavailabletoviewattheregistrationdeskIGNSS2013BookofAbstractsForOralandPosterPresentationswww.
ignss.
orgOralPresentationsAbstracts–Tuesday16July,2013Session1:PlenarySession0900-1030WhatdoestheMulti-GNSSEraMeanforAustraliaandtheRegionWelcomeAddress-CapitalisingonAustralia'sUniqueGeopoliticalAdvantageintheMulti-GNSSEraMatthewBHigginsPresidentoftheIGNSSSocietyManagerGeodesyandPositioning,DepartmentofNaturalResourcesandMines,QueenslandAustraliaTelephone:+61738963754Facsimile:+61738963697Email:matt.
higgins@qld.
gov.
auABSTRACTThispresentationwillcommencewithanoverviewoftheIGNSSSymposium,withparticularattentiontothePlenarySessionsdesignedtoaddressimportantissuesforAustralianGNSSusers.
ItwillthengoontooutlinerecentworkonthedevelopmentofaGNSSStrategicPlanforAustraliaanditsidentificationofsomeissuesspecifictoAustraliaasweentertheMulti-GNSSera.
ThepresentationwillexamineindetailaspecificfindingintheStrategicPlanrelatedtohowAustraliacancapitaliseonitsuniquegeopoliticaladvantagesasadevelopedeconomywithasophisticatedGNSSuserbase.
ThoseadvantagesstemfromthefactthatAustraliawillhaveaccesstothetworegionalnavigationsatellitesystemsbeingdevelopedbyJapanandIndiainadditiontothe4globalsystemsfromChina,Europe,RussiaandtheUnitedStatesofAmerica.
KEYWORDS:AustralianGNSSUsers,GeopoliticalAdvantages,GNSSStrategicPlan,GNSS,RNSS.
EnsuringThereisLeadershipfortheAustralianGNSSCommunityJoeAndrews,SpaceCoordinationOffice,CANBERRA,AUSTRALIAAbstractNotProvidedAdoptingaWhole-of-NationApproachtoaSustainable,Multi-GNSSEnabledNationalPositioningInfrastructureDrJohnDawson,GeoscienceAustralia,CANBERRA,AUSTRALIAAbstractnotprovidedSession2:PlenarySession1100-1230PresentationsfromtheGNSSSystemProvidersgivingupdatesontheirsystemsandcommentsontheirperspectiveontheissuesraisedinSession1PlenaryU.
S.
GPSPolicy,ProgramandInternationalUpdateJeffreyAuerbachOfficeofSpaceandAdvancedTechnology,DepartmentofState,UnitedStatesPhone:12026632388Fax:12026632402Email:auerbachjm@state.
govABSTRACTThispresentationprovidesanupdateonthestatusofUnitedStates(U.
S.
)GlobalPositioningSystem(GPS)policyandprogram,includingitsaugmentationsystems.
The2010U.
S.
NationalSpacePolicyprovidesguidancetoachievethespace-basedpositionnavigationandtiminggoalofmaintainingleadershipintheservice,provision,anduseofGlobalNavigationSatelliteSystems.
Akeycomponentincludesthecontinuedefforttoachievecompatibleandinteroperablesystemsthroughouttheworld.
Theprimarymeansforaccomplishingthisisthroughbilateralandmultilateraldiscussionsandforums.
TheU.
S.
alsocontinuestomodernizetheGPSanditsaugmentationsystems,providingnewcapabilitiesinanefforttoprovidethehighestlevelofservicetousersaroundtheworld.
TheU.
S.
performancecommitmentforcivilserviceuseoftheGPShasbeenmetcontinuouslysinceDecember1993.
KEYWORDS:GPS,Compatibility,InteroperabilityGLONASSGovernmentPolicy,StatusandModernizationPlansTatianaMirgorodskayaInformationandAnalysisCenterforPNT/CentralResearchInstituteofMachineBuilding/Roscosmos/RussianFederationTel.
:+74955134882;Fax:+74955134139;e-mail:tatyana.
mirgorodskaya@glonass-iac.
ruSergeyRevnivykhInformationandAnalysisCenterforPNT/CentralResearchInstituteofMachineBuilding/Roscosmos/RussianFederationTel.
/Fax:+74955134139;e-mail:sergey.
revnivykh@glonass-iac.
ruABSTRACTThepresentationwillfocusonprogrammaticissues,currentstatus,performanceandmodernizationofGLONASSsystem.
ItwillcoverthebackgroundprinciplesofthegovernmentpolicybehindGLONASSProgramimplementation.
GLONASSdeploymentphaseiscompleteandtheGLONASSSustainment,DevelopmentandUtilizationProgramisunderwaybringingnewopportunitiestotheusersandnewchallengestotheRussianGovernment.
Thepresentationwillgivesomereviewofthemodernizationeffortscurrentlyunderwaywithrespecttospaceandgroundsegments,signals,augmentationsandapplications.
TheinformationonGLONASSperformanceevolutionintermsofavailabilityandaccuracywillbeprovidedfollowedbytheoutlineofsystemmodernizationplanswiththeviewofincreasingthatperformance.
ThepresentationwillalsoincludeabriefsummaryoftheSystemofDifferentialCorrectionsandMonitoringwhichisconsideredasaconstituentpartofGLONASS.
WiththeincreasingroleofGLONASSastheoperatingGNSSinthemulti-GNSSinfrastructureRussia'scooperationwithotherGNSSproviderswillbecomemoreimportantintermsofprovidinggreaterinteroperabilitybetweenexistingandemergingsystems.
ThepresentationwilladdressinternationalactivitiesofRussianFederationinthefieldofGNSSandspace-basedPNT.
KEYWORDS:GLONASS,SDCM,CDMAsignals,interoperability,internationalcooperation.
PositioningPerformanceofBeiDouNavigationSatelliteSystemQileZhaoGNSSResearchCenter,WuhanUniversity,ChinaPhone:0086-27-68778240Fax:0086-27-68778971Email:zhaoql@whu.
edu.
cnABSTRACTFollowingthegeneralguidelineofstartingwithregionalservicesandthenexpandingtoglobalservices,theBeiDouSystemissteadilyacceleratingtheconstruction.
Bytheendof2012,theBeiDouSystemalreadyconsistsoffourteennetworkingsatellites,includingfiveGEOsatellites,fiveIGSOsatellites,andfourMEOsatellites,andownsfulloperationalcapabilityforChinaanditssurroundingareas.
ThepositioningperformanceofcurrentBDS(with5GEO+5IGSO+4MEOsatellites)fromJanuarytoJuneof2013isintroducedinthispresentation.
InChinaanditssurroundingarea,thepositioningaccuracyusingBDSopeningserviceisabout10metersinbothhorizontalandverticaldirection.
SomehighpreciseapplicationsusingNetRTKandPPPmethodarealsoshowninthiscontribution.
FromtheresultsweknowthatuserscangethighpreciseserviceusingBDSonly,andbothBDSandGPSuserscanbebenefittedfromcombinationofthetwosystems.
KEYWORDS:BDS,GPS,Positioningperformance,PPP,NetRTK.
Session3:PlenarySession1330-1530GNSSSystemProvidersandtheKeyIssuesforAustraliaandtheRegion(continued)CurrentStatusofQuasi-ZenithSatelliteSystemMrEigoNomuraCounselorforOfficeofNationalSpacePolicy,CabinetOffice,GovernmentofJapanAbstractNotProvidedInformationCentresoftheInternationalCommitteeonGlobalNavigationSatelliteSystemsSharafatGadimovaOfficeforOuterSpaceAffairs/UnitedNationsOfficeatVienna/Austria+431260605479/+431260605830/sharafat.
gadimova@unvienna.
orgABSTRACTEffortstobuildcapacityinspacescienceandtechnologyareconsideredamajorfocusoftheOfficeforOuterSpaceAffairsandareofspecificinteresttotheInternationalCommitteeonGlobalNavigationSatelliteSystems(ICG)withparticularreferencetoglobalnavigationsatellitesystems(GNSS).
SucheffortsshouldaimtoprovidesupporttotheregionalcentresforspacescienceandtechnologyeducationaffiliatedtotheUnitedNations(http://www.
unoosa.
org/oosa/en/SAP/centres/index.
html),whichwouldalsoactasinformationcentresforICG.
TheICGExecutiveSecretariatandGNSSprovidersseetwoareaswheretheycanassisttheprocessofthedevelopmentandprogresstowardsthefurtherdevelopmentandprogresstowardsthefurtherdevelopmentofICGInformationCentres:(1)thetechnicallevel,whichwillincludevariousGNSStechnologies,and(2)thecooperativelevelwithpossiblecollaborationwithindustryleadersandlinkageswithcurrentandplannedsystemandaugmentationsystemproviders.
LinkageswouldbefacilitatedthroughcollaborationwiththeICGProviders'Forum(seminars/trainingsandsupportivematerials),aswellascommunicationandoutreachtothewidercommunitythroughtheICGinformationportal,mailinglists,brochuresandnewsletter.
KEYWORDS:ICG,GNSS,informationcentres.
Session4:PlenarySession1600-1730TheRelianceofKeyIndustriesonGNSSGNSSUseandRelianceintheAgriculturalIndustriesTimNealePrecisionAgriculture.
com.
auMobile:+61428157208,tim@precisionagriculture.
com.
auABSTRACTAgriculturehasbenefitedgreatlyfromtheproliferationofGNSStechnology.
AustraliahasbeenleadingtheworldinhighprecisionGPSsincethe1990's,followingthedevelopmentoftheauto-steerguidancetechnologyfortractors.
SincethenwehaveseendevelopmentsinGNSSaccess,advancesinsoftwareandhardware,improvedRTKperformance,andCORSnetworkscoveringlargeareas.
Tractors,sprayers,seeders,andharvesterscannowbesteeredhandsfreeforarelativelylowcost.
Autosteersystemshavedroppedfromaround$120,000perunitinthelate1990's,toaround$25,000perunittoday.
Wehaveseenarationalisationinthenumberofdominantmanufacturesinrecentyearsfromaroundeighttotwo.
Notonlydoesagriculturerelyonhighprecisionguidanceformachineryauto-steering,butawiderangeofapplicationsuseloweraccuracyGNSSsuchasfarmmapping,variableratecontrol,andyieldmapping.
ThesesystemscanautonomousGNSSsuccessfullyduetoselectiveavailabilitybeingturnedoff.
Ouradoptionratesarealmostcertainlytobethehighestofanywhereintheworld,where80%ofcropfarmersinarecentstudyclaimtheyuseautosteer,and30%createyieldmapsusingGNSS.
Therearearound42,000cropfarmersinAustralia,whichmeansthattherecouldbeinexcessof30,000GNSSsystemsinuseforautosteer,and12,000usedingrainharvesters,ifthestudyresultswereextrapolated.
Robotics,drones(UAV's),andmachinecontrolarealsoemerginginAgriculture;allofwhichrelyonGNSS.
KEYWORDS:PrecisionAgriculture,Farming,Autosteer,Guidance.
CORSRTKCorrectionsforConstructionProjects–Status,BenefitsandWhat'sNextMartinNixCEOPositionPartnersPty.
Ltd.
AustraliaPhone:+61298980066Fax:+61298980700email:mnix@positionpartners.
com.
auABSTRACTItisalmost5yearssincethereleaseoftherecommendationoftheAllenConsultingReportontheEconomicBenefitsofHighResolutionGNSStoestablishastandardizednationwideCORSinfrastructure.
Theconstructionindustry,asoneof3keyindustriesstudiedinthereport,isexpectedtogainbetween$6and$10billioninproductivitybenefitsbetween2008and2030fromastandardizednationalCORSnetwork.
ThepaperreviewstheprogressofCORSinfrastructureandtheuseofCORSderivedRTKcorrectionsintheconstructionindustryinthelast5years.
PracticalexamplesofprojectsusingtheCORSdeliveredRTKversusothermethodsarecomparedforacostbenefitcomment.
TheconstructionapplicationsexaminedareGNSSmachinecontrolandtracking,GNSSsurveyingandnewdevelopmentsusingGNSStechnologysuchasUAVmapping,mobilescanningandcollisionavoidance,TechnicalandcommercialbarrierstofurtheradoptionofCORSderivedRTKcorrectionsremain.
Yet,trendsareuncoveredthatindicatefutureadoptionratesarelikelytoincrease.
Itisconcludedthattherearemanytechnical,commercialandorganizationalissuestosolvebeforetheeconomicbenefitsoftheAllenreportareachievedfortheconstructionindustry.
KEYWORDS:CORS.
MachineControl,RTKcorrections,AllDayRTK,construction.
MaritimeApplicationofGNSSandtheNeedforResilientPNTCapt.
MustafaAliAustralianMaritimeSafetyAuthorityP+61(0)262795018,F+61(0)262795966,mustafa.
ali@amsa.
gov.
auABSTRACTInternationalshippingcarriesmorethanninetypercentofglobaltradeandreliesalmostentirelyonGlobalNavigationSatelliteSystem(GNSS)forPosition,NavigationandTiming(PNT)information.
GNSShasnowbecometheprimarymeansbywhichshipsdeterminetheirpositions.
AndPNTinformationfromGNSSisvitalinputforshipboarddevicessuchasAutomaticIdentificationSystem(AIS),ElectronicChartDisplayandInformationSystems(ECDIS),GlobalMaritimeDistressandSafetySystem(GMDSS),LongRangeIdentificationandTracking(LRIT)andDynamicPositioning(DP)systems.
Inturn,AISinformationcanbeusedbycoastalstatestofulfilarangeoftheirobligations.
Inrecentyears,thedevelopmentofnewshipboardnavigationtechnologieshasbeenrapid.
Inordertobetterintegratenewandexistingnavigationalaidsandenhanceberth-to-berthnavigation,theInternationalMaritimeOrganization(IMO)isleadingthedevelopmentofan"e-navigation"concept.
Oneofthecentralpillarsofe-navigationisresilientPNT.
AlthoughtheubiquityofGNSSmakesitaprimeproviderofPNTinformationforseverale-navigationapplications,thevulnerabilityofGNSSisasourceofconcern.
Spaceandgroundsegmentfailures,atmosphericdisturbancesandunintentionalandintentionalinterferencecanallimpactontheperformanceofGNSS.
IMO'sworkone-navigationhashighlightedtheimportanceofresilientPNTsystemsandhasrecognisedthatdespiteagrowingnumberofsatellitesystems,theyallsufferfromasinglemodeoffailure.
AmongstthevariousalternativesmootedforPNTservices,terrestrialsolutionscanbeconsideredandfurtherdevelopedformaritimeuse.
Suchsolutionsshould,asfaraspracticable,beapplicablegloballyandnotresultinregionaldifferentiation.
ApracticalandachievablesolutiontomitigatethepotentialeffectsofGNSSvulnerabilitiesisimportanttoensurethesafenavigationofshipsinconfinedwaters,environmentallysensitiveareasandfortheoperationsoftheoffshoreoilandgasindustry.
OralPresentationsAbstracts–Wednesday17July,2013Session5:PlenarySession0900-1040CooperativeIntelligentTransportSystemsandGNSSEstablishingaFrameworkforCooperativeIntelligentTransportSystemsDennisWalshDepartmentofTransportandMainRoads,Queensland,AustraliaP:+61730668543,E:dennis.
j.
walsh@tmr.
qld.
gov.
auStuartBallingallAustroads,AustraliaP:+61392296095,E:stuart.
ballingall@roads.
vic.
gov.
auABSTRACTCooperativeIntelligentTransportSystems(C-ITS)referstoaubiquitousecosysteminwhichvehicleswillreceiveandsharedatawirelesslywithothervehiclesandroadsideunits.
Thiswillenablearangeofemergingapplicationsaimedatimprovingsafety,efficiencyandenvironmentaloutcomesfromourlandtransportnetwork.
Alsoreferredtoas'connectedvehicles',C-ITSwilluseacombinationoftechnologiesincludingDedicatedShortRangeCommunications(DSRC),cellularnetworks,GlobalNavigationSatelliteSystems(GNSS)andenhanceddigitalroadmaps.
Significanttechnicaldevelopmentsarecontinuinginternationally,includingeffortstogloballyharmonisestandardsandprocesses.
ProgresshasalsobeenmadewithregulationsandpoliciestosupportthedeploymentofC-ITS,particularlyinEurope,theUSAandJapan.
BasedonthestatusandplanningofinternationalC-ITSinitiatives,itisexpectedthatC-ITSenabledvehicleswillbeintroducedtoglobalmarketsfrom2015.
AustroadsistakingaleadroleinestablishingaregulatoryandoperationalframeworkthatwillenableC-ITSdeploymentinAustralia.
TherequiredC-ITSframeworkwillcoverpolicyandregulation,spectrummanagement,technicalstandards,platformrequirementsandoperationalarrangements.
ToensurethelocalC-ITSframeworkachievestherequiredinteroperability,marketaccess,andoptimisedtransportoutcomes,itiscriticalthatitisharmonisedwithinternationalstandardsandbestpracticeswherepossible.
KEYWORDS:CooperativeIntelligentTransportSystems(C-ITS),ConnectedVehicles,VehiclePositioning,OperationalFramework,RegulatoryFrameworkGNSSPositioningRequirementsforCooperativeIntelligentTransportSystemsMatthewBHiggins(1)PresidentoftheIGNSSSocietyManagerGeodesyandPositioning,DepartmentofNaturalResourcesandMines,Brisbane,AustraliaTelephone:+61738963754Facsimile:+61738963697Email:matt.
higgins@qld.
gov.
auYanmingFeng(2)Professor,ScienceandEngineeringFaculty,QueenslandUniversityofTechnology,Brisbane,AustraliaTelephone:+61731381926Facsimile:+61731389390Email:y.
feng@qut.
edu.
auABSTRACTCooperativeIntelligentTransportSystems(C-ITS)representaverydemandingsuiteofemergingapplicationforprecisepositioning.
ThispresentationwilloutlineworkundertakenrecentlyforAustroads(viatheAustralianRoadsResearchBoard)onthetechnicalbackgroundandanalysisofpositioningrequirementsforC-ITS.
PotentialC-ITSapplicationsrangefromsimplealertsforadriveraboutproblemsontheroadaheadtosophisticatedautomaticcollisionavoidancesystems.
AkeypieceoftheworkthereforewastodevelopaframeworkthatcanbeusedforcharacterisinganddescribingthepositioningrequirementsacrossthatrangeofC-ITSapplications.
Oneexampleistheneedtodifferentiaterequirementsacrossthreepositioningaccuracylevelsthatwecharacteriseasmetre(forroad-levelpositioning),submetre(forlane-level)anddecimetre(forwhere-in-lane-level).
Theworkalsoexaminedissuessuchasthevariationintimelinessrequirementsandfoundthatroad-levelapplicationscantypicallytolerateaboutonesecond(1Hz),whileforlane-levelandwhere-in-lane-levelapplicationsitis0.
1second(10Hz).
Theresearchalsodefinedandthenexaminedcriticalissuesforanumberofothervehiclepositioningperformancerequirementssuchascontinuity,availability,integrityandinteroperability.
AnotherimportantaspectoftheworkwastoidentifytheneedfortheroadtransportsectortoworkmorecloselywithotherkeysectorsofpositioninguserstoensurethatC-ITSrequirementsarefactoredintoplanningofinitiativesliketheNationalPositioningInfrastructurePlanandpossiblefutureSpaceBasedAugmentationsforGNSSusersinAustralia.
KEYWORDS:CooperativeIntelligentTransportSystemsC-ITS,GNSS,positioningrequirements,accuracy,timeliness,continuity,availability,integrity,interoperability.
TechnologicalLimitstoPositioningAccuracyforC-ITSAndrewGDempsterAustralianCentreforSpaceEngineeringResearch,SchoolofElectricalEngineeringandTelecommunications,UniversityofNewSouthWalesPh:+61293856890,a.
dempster@unsw.
edu.
auABSTRACTRequirementsandapplicationsofCooperativeIntelligentTransportSystems(C-ITS)arebecomingbetterdefined.
Itisimportantthatanyassumptionsregardingtheaccuracy,availabilityandintegrityofpositionsusedinC-ITSarewellfounded.
ThispresentationexaminestheuseofDedicatedShort-RangeCommunications(DSRC),theIEEE802.
11pstandardoperatingat5.
9GHz,toaidindeliveringC-ITSgoals.
ForthepositioningrequirementsofC-ITS,DSRCcanbeusedasacommunicationsmediumalone(i.
e.
reporting),asanenablerofvehiclead-hocnetworks–VANETs(usinglocalisationtechniques),orasasourceofrawmeasurementsforuseinthepositionsolution.
Thelattertwocanbeconsideredseparatelyandtogetherasmethodsofimprovingpositioningover,say,GPS.
However,therearelimitstotheextraaccuracyofferedbythesetechniques,soitispossiblethatDSRCdoesnotbringsufficientextracapabilitytosupportalloftheC-ITSapplications.
KEYWORDS:Upto5keywordsin11ptTimesNewRomanfont,separatedbycommas;thesewillassistinthecross-indexingofthepaper.
LeavetwolinespacesbeforetheIntroductionbelow.
Session6A:ChineseSatNav1110-1250TheBeiDouNavigationMessageOliverMontenbruckDLR,GermanSpaceOperationsCenter,GermanyPhone+49(8153)28-1195,fax-1450,oliver.
montenbruck@dlr.
dePeterSteigenbergerTechnischeUniversittMünchen,Germanysteigenberger@bv.
tum.
deABSTRACTWiththedisclosureofapublicsignalICDinlateDec.
2012,worldwideuserscannowgetaccesstothebroadcastnavigationmessagestransmittedbytheBeiDousatellitesandemploythemforreal-timenavigation.
FollowingasummaryoftheBeiDounavigationmessagecontents,itsspecificcommunalitiesanddifferenceswithrespecttootherGNSSconstellationsarehighlighted.
BasedonBeiDounavigationdatacollectedinthefirstquarterof2013byvariousreferencestationsinAsia,AustraliaandEurope,theaccuracyoftheprovidedorbitandclockinformationandtheresultingimpactontheachievablepositioningaccuracyareassessed.
Forcomparison,preciseorbitdeterminationresultsforBeiDouMEO,GEO,andIGSOsatellitesarecomputedfromobservationsofagloballydistributedsetofBeiDou-capablemulti-GNSSmonitoringstationsoftheMGEXandCONGOnetworks.
WhileusersclosetotheChinamainlandwillgenerallybenefitfromaverylowephemerisage,thesamecannotbeguaranteedforremoteregionsinviewoflimiteduplinkstations.
TheresultingvariationinephemerisageandqualityisevaluatedforselectedtestsitesinsideandoutsidetheAsia-Pacificregion.
Furtherattentionisgiventosignal-specificgroupdelaysandtheirproperconsiderationinamulti-GNSSpositioningsolution.
TheTimingGroupDelayparametersprovidedinthenavigationmessagearecomparedwithvaluesderivedfromamonitoringstationsandathinlayerionospheremodel.
KEYWORDS:BeiDou,BroadcastEphemeris,multi-GNSSpositioning,TGD,MGEXAnalysingthePotentialBenefitsofAddingBeiDou/CompassSatellitestotheTrimbleCenterPointRTXServiceHerbertLandau,MarkusBrandl,XiaomingChen,RalfDrescher,MarkusGlocker,RodrigoLeandro,MarkusNitschke,DagobertoSalazar,UlrichWeinbach,FeipengZhangTrimbleTerraSatGmbH,GermanyPhone:+49810274330Fax:+4981027433131ABSTRACTTheTrimbleCenterPointRTXserviceprovidesreal-timeGNSSpositioningwithglobalcoverageandfastinitialization.
Theaccuracyofkinematicpositioningisbetterthan4cminhorizontal(95%)atanytime,anywhere.
Itisachievedafteratypicalconvergencetimeof30minutesorless.
TheCenterPointRTXsystemisbasedonthegenerationofpreciseorbitandclockinformationforGNSSsatellites.
TheCenterPointRTXsatellitecorrectionsaregeneratedinrealtimeusingdatastreamsfromapproximately100globallydistributedreferencestationsofTrimble'strackingnetwork.
Sinceitsintroductionin2011thesystemhasundergonetwomajorreleasesinspring2012andspring2013,whichincludedthegeneralperformanceimprovementwithrespecttoconvergencetimeandtheintroductionofadditionalserviceslikeRangePointRTXandfeatureslikexFill.
TheTrimbleCenterPointRTXservicetodaysupportsGPS,GLONASSandQZSSsignals.
Recentlyemphasiswasputontheevaluationofthepossibilitytoincludeadditionalsatellitesystemsintotheservice.
TheauthorsstartedtoresearchtheabilitytointegrateBeiDou/CompassintotheRTXsystem.
ResultsontheachievableorbitandclockqualityforBeiDousatellitesarepresentedusingtheTrimbleCenterPointRTXtrackingnetwork.
ThebenefitofusingBeiDouinRTXpositioningwasanalysedandfirstresultsareshownusingaprototypeimplementationKEYWORDS:BeiDou,Orbitandclockestimation,Real-timePPP,TrimbleCenterPointRTXVarianceAnalysisofPseudo-RangeNoisesofGPSandBeidouGNSSSignalsLeiWangScienceandEngineerFacultyQueenslandUniversityofTechnology,Australia(+61)0416892716I62.
wang@qut.
edu.
auCharlesWangScienceandEngineerFacultyQueenslandUniversityofTechnology,Australia(+61)0410060668cc.
wang@qut.
edu.
auYanmingFengScienceandEngineerFacultyQueenslandUniversityofTechnology,AustraliaPhone:0731381926Fax:0731389390emaily.
feng@qut.
edu.
auABSTRACTObservationweightingstrategyisoneofthechallengingissuesinprocessingofmulti-GNSSsignals.
Falseorsimplevariancesettingsbetweenmeasurementsfromtwosystemscancausedegradednavigationsolutionsinsteadofimprovingthesolutions.
Furthermore,reasonablepriorcodevariancesettingsbetweensystemsandsatellitescanimproveambiguityresolutionandpositioningaccuracyaswell.
Thispaperpresentedanewcodevarianceestimationmethodbasedontime-differenced(TD)observations,whichenablesrealtimeandsingle-receivercodevarianceestimation.
Thechallengeofcodevarianceestimationishowtoseparaterandomnoisefromsystematicbiasandhowtoevaluatethevarianceofrandomnoisesobjectively.
Currentpriorcodevarianceestimationmethodreliesonsingledifferenceobservationsbetweentworeceiverstoreducetheeffectsofsystematicbiases.
Thismethodmayperformwellintheshortbaselineorzerobaselinescenarios.
However,itisnotapplicablefordataprocessingwithzerodifferencedmeasurements.
Theproposedmethodcaneliminatetheeffectsofthemajorsystematicbiasesinthetimedifferencedcode-phaseobservations.
Itcanestimatethevariancecomponentsofcodemeasurementsoveramovingobservationwindowinrealtimemanner,suitableforrealtimedataprocessing.
Theexperimentalresultsindicatethatthetimedifferencedcodeobservationerrorscanbetreatedasnormallydistributedwhitenoises,althoughthetimecorrelationbetweenundifferencedcodenoisesareofconcerns.
CodeobservationsfromthreetypesofGPS/Beidoureceiverscollectedovermanyhoursareanalysedusingtheproposedapproach.
Theresultsshowthatthebehaviourofcodenoisesdependsonthesignaltrackingmethod.
Notallcodevariancesgenerallydependonelevationangleandthecodevariancesfordifferentsatellitesystemsaredifferentaswell.
Hence,areceive-specifiedcodevariancemodelisgenerallyrecommendedintheprocessingofmulti-GNSSsignals.
KEYWORDS:Stochasticmodel,Multi-GNSS,VarianceEstimation,GNSSobservables,timecorrelationTheCurrentARAIMAvailabilityAccordingtoLPV-200UsingGPSandBeiDouinWesternAustraliaAhmedEl-MowafyDept.
ofSpatialSciences,CurtinUniversityofTechnologyTel:+61892663403,Fax:+61892262703,a.
el-mowafy@curtin.
edu.
auBalwinderAroraDepartmentofAppliedPhysics,CurtinInstituteofRadioAstronomy,CurtinUniversityofTechnologyTel:+610892669899,Fax:+610892669246,B.
arora@postgead.
curtin.
edu.
auABSTRACTTheLocalizerPerformancewithVerticalguidanceat200feet(LPV-200)isasetofproceduresforaircraftprecisionapproachesdownto200feet(61metres).
WiththemodernisedGPSandemergingGNSSconstellations,itistargetedtogloballyfulfilrequirementsofLPV-200bytheyears2020-2025.
FulfilmentofLPV-200withintegritymonitoringwillsupporttheuseofGNSSasasupplementary/primarymeansforaircraftnavigation.
Inthisinvestigation,availabilityoftheAdvancedReceiverAutonomousIntegrityMonitoring(ARAIM)approachwillbeinvestigatedaccordingtoLPV-200requirementsinWesternAustralia(WA).
Twocaseswillbeconsidered,firstlyusingGPSaloneandsecondlywhenaugmentingGPSsatelliteobservationswiththecurrentregionalBeiDouconstellationof15satellites.
AustraliaenjoysanexcellentlocationinreceivingBeiDousignals,whichmayhelpinimprovingintegritymonitoringduetounavailabilityoftraditionalSBASserviceoverAustraliathatincludesintegrityinformation.
Inthispaper,theLPV-200requirementswillfirstbereviewed.
Next,theARAIMmethodwillbediscussedincludingtheairborneerrormodel,satelliteintegrityfailuremodel,andassumptionsonallocationsofthedifferentcasesofintegrityfaultsusingGPSalone.
TheimpactofusingBeiDousatelliteswillbeaddressed.
AssumptiononitserrormodelandallocationsofprobabilityofintegrityfaultswhenintegratingBeiDouwithGPSwillbediscussed.
ThedatausedinthisstudywerecollectedatsixIGSstations,well-distributedacrossWA,andareclosetomainairportsintheregion.
DuetoBeiDoudataavailability,testingofitsactualdataintegratedwithGPSwasonlyperformedatonesite(Perth).
ResultsshowthatthecurrentGPSconstellationalonedoesnotfulfilLPV-200requirementsinWA,withanaverageARAIMavailabilityof99.
9%acrossthestudyarea.
However,usingGPSwiththeBeiDoudramaticallyimprovesavailablyofARAIM.
KEYWORDS:IntegrityMonitoring,ARAIM,LPV-200,GPS,BeiDou.
QualityAnalysisofaCombinedCOMPASS/BeiDou-2andGPSRTKPositioningModelRobertOdolinski(1)GNSSResearchCentre,CurtinUniversityofTechnology,Australia+61892663157&+61892662703,email:robert.
odolinski@curtin.
edu.
auPeterJ.
G.
Teunissen(2)GNSSResearchCentre,CurtinUniversityofTechnology,Australia,andDelftUniversityofTechnology,theNetherlands+61892667676&+61892662703,email:P.
Teunissen@curtin.
edu.
auDennisOdijk(3)GNSSResearchCentre,CurtinUniversityofTechnology,Australia+61892663157&+61892662703,email:D.
Odijk@curtin.
edu.
auABSTRACTTheChineseCOMPASS(BeiDou-2)NavigationSatelliteSystemattainedinitialregionaloperationalstatusintheendofDecember2011,andcanprovidePositioning,NavigationandTiming(PNT)servicesinthewholeAsia-Pacificregion.
TheCOMPASSfullconstellationisexpectedbyyear2020withmorethan30satellites,andwillprovideglobalcoverage.
AustraliaisalreadyabeneficiaryoftheregionalCOMPASSsystemasenoughsatellitesareavailableforpositioning.
AcombinedCOMPASS-GPSsystemincreasestheredundancy,whichallowsforhigheraccuracyandimprovedintegrity.
InthiscontributionwewillcomparethecombinedsystemperformancewiththeCOMPASS-andGPS-onlysystems.
ThecomparisonswillbemadeonmeasuresofprecisionoftheestimatedGNSSparametersandtheirreliability,formallyaswellasempirically.
Reliabilityisameasureofrobustnessoftheunderlyingmodel,andcanbecategorizedintointernalandexternalreliability.
Internalreliabilityconcernstheabilityofthesystemtotesttheobservationsformodellingerrors,andexternalreliabilityisreferredtoastheconsequencesontheestimatedparameterswhensuchmodelmisspecificationsareleftundetected.
Comparisonswillinvolvesingle-frequencyvs.
multiple-frequencies.
KEYWORDS:COMPASS/BeiDou-2,GPS,RTK,precision,variancematrix,reliability,MinimalDetectableBias(MDB)Session6BInertialNavigationSystem1110-1250ZeroVelocityUpdatewithStepwiseSmoothingforInertialPedestrianNavigationYanLiFacultyofEngineeringandInformationTechnology,UniversityofTechnology,Sydney,Australian(02)95143148Yan.
Li-11@student.
uts.
edu.
auJianguoJackWangFacultyofEngineeringandInformationTechnology,UniversityofTechnology,Sydney,Australian(02)95142634Jianguo.
Wang@uts.
edu.
auABSTRACTZerovelocityupdate(ZUPT)isaneffectivewaytocorrectlowcostinertialmeasurementunit(IMU)errorswhenitisfoot-mountedforpedestriannavigation.
Thestancephaseinstepsprovideszerovelocitymeasurementforinertialsensorerrorcorrection.
Duringthisintegrativeandrecursivescheme,theerrorsofestimatedpositionandvelocitygrowwithtimerapidly,thusZUPTappliedateachstepleadstosharpcorrectionsanddiscontinuitiesintheestimatedtrajectory.
Rauch-Tung-Striebel(RTS)smootheriscommonlyusedforbridgingGPSoutages.
RTSisatwopassfilteroperatedinpostprocessingmodewhichcangetanoptimalestimateofthefilterstates.
TheforwardpassrunsasastandardKalmanfilterbutstoreallthefilterstateswhilethebackwardpassrunninginareversetimefashionusesthestoredstatestocomputesmoothedstates.
Inthispaper,weproposeaclosedloopRTSsmoothingfilter,whichcanachievenearreal-timebasedona24errorstatesextendedKalmanfilter(EKF).
UnlikecommonRTSsmoother,astepwisebackwardfilterisimplementedtoeliminatethesharpcorrectionsoverthesteps.
Theimpactofthenearreal-timesmoothingfilterfordifferentstepmanners(walkandrun)isillustratedandanalysed.
Experimentalresultsshowthattheproposedmethodcandramaticallyimprovepedestriannavigationsolutions.
Aprototypeisdevelopedfordemonstration.
Themethodcanalsobeusedinsportsandbodyartetc.
researcheswhenprecisetrajectoryoffootmovementisrequired.
KEYWORDS:Pedestriannavigation,INS,ZUPT,RTSsmoothing.
ImplementingQuaternionBasedAHRSonaMEMSMultisensorHardwarePlatformGangSun1.
SchoolofMechanicalEngineering/NanjingUniversityofScienceandTechnology/China2.
SchoolofSurveyingandGeospatialEngineering/UniversityofNewSouthWales/AustraliaT:86-025-8431-5471,F:86-025-8431-5471,E:sg_nj@hotmail.
comYongLiSchoolofSurveyingandGeospatialEngineering/UniversityofNewSouthWales/AustraliaT:61-2-9385-4173,F:61-2-9313-7493,E:yong.
li@unsw.
edu.
auJiawei(Steven)XieSchoolofSurveyingandGeospatialEngineering/UniversityofNewSouthWales/AustraliaT:61-2-9385-4173,F:61-2-9313-7493,E:stevenxie@live.
cnMatthewGarrattSchoolofEngineeringandInformationTechnology/UniversityofNewSouthWales/AustraliaT:61-2-6268-8267,F:61-2-6268-8581,E:m.
garratt@adfa.
edu.
auChangmingWangSchoolofMechanicalEngineering/NanjingUniversityofScienceandTechnology/ChinaT:86-025-8431-5471,F:86-025-8431-5471,E:wangchangming@mail.
njust.
edu.
cnABSTRACTOverthelastdecadeorsomicro-electromechanicalsystem(MEMS)technologyhasbeenwidelyusedinmanynavigationapplicationssuchaspedestrians,aircraft,landvehiclesandrobots,becauseofitsadvantagesintermsofprice,accuracyandsize.
Thispaperpresentsanovellow-costmultisensorhardwareplatformknownas"NAVCON",whichisdesignedfornavigationandcontrolofquad-rotorunmannedaerialvehicles.
ItisasmartboardwithGPS,MEMSaccelerometerandgyroscope,magnetometer,barometerandarichsetofperipheralinterfaces.
OnesignificantfunctionofthisplatformonUAVistheattitudeandheadingreferencesystem(AHRS),whichoutputsthepitch,rollandyawinrealtimetoassistthecontrolunittobalancetheaircraftortoperformspecificactions.
But,thelow-costinertialsensorsusuallyhavelargebiasesandnonlinearcharacteristicsintheiroutputs.
TocorrecttheerrorsoftheNAVCON,errormodellingandcalibrationareveryessential.
Thegeneralcalibrationmethodusuallyhasstrictrequirementsonexperimentalenvironmentandequipment.
Forcalibratingsuchlow-costsensorsmoreconveniently,theauto-calibrationstrategybasedonellipsoidfittingforaccelerometerandmagnetometerispresented.
Testresultshowsthattheauto-calibrationstrategycanobtainthesameaccuracyasthetraditionalmethod,butitissimplerandmoreefficient.
AquaternionbasedextendedKalmanfilter(EKF)isalsoproposedforimplementingtheAHRSfunctionontheNAVCON.
InadditiontotheonlinesensorbiasestimationandcompensationbyEKF,themeasurementnoisecovariancematrixissetadaptivelyinconsiderationofthedynamicdisturbanceinbothaccelerometerandmagnetometer.
Moreover,anewvariablemonitoringthelongtermchangeonmagneticfieldstrengthisintroducedtoimprovetherobustnessofmagneticdisturbancedetectionstrategy.
Inthetests,proposedAHRSalgorithmonNAVCONiscomparedwiththeXsens'AHRSproductMTidirectly.
Theresultshowsagoodaccuracy.
Andtheimproveddisturbancedetectionstrategycanidentifythebodymotionanddetectthemagneticdisturbancecorrectly.
KEYWORDS:MEMS;AHRS;quaternion;EKF;multisensorplatform.
Real-timeNonlinearComplementaryObserverforLow-costInertialAttitudeSystemDafizalDerawiMalaysia-JapanInternationalInstituteofTechnology,UniversitiTeknologiMalaysiadafizal2@live.
utm.
myJonghyukKimResearchSchoolofEngineering,TheAustralianNationalUniversityjonghyuk.
kim@anu.
edu.
auABSTRACTThispaperaddressesthereal-timeimplementationofanonlinearcomplementaryattitudeobserveronalow-costInertialMeasurementUnit(IMU)systemaimingbuiltin-houseforsmall-scaleflyingrobots.
Weproposeanewapproachforattitudeestimationinreal-timesystemonembeddedhardwarebyusinganonlinearcomplementaryobserveronthespecialorthogonalgroupofrotationmatricesSO(3),ratherthanconventionalExtendedKalmanFilter,toexploitthenear-globalconvergencepropertyoftheobserver.
Theproposednonlinearcomplementaryobservercombinesthepositivefeaturesofinertialsensorswherethegyroscopeisusedasthemainsourceofshort-termorientationinformationofthevehicle,whilstaccelerometerandmagnetometerareusedtocorrectlong-termdrifterroringyroscopeanderrorsincomputations.
Alos-costembeddedIMUboardhasbeenbuiltin-housecostinglessthan$50,aimingforfutureintegrationwithGPSandvisionsensors.
Theexperimentalresults,bothinindoorandoutdoorflyingenvironmentwillbepresentedshowingtheproposedsystemperformsreliablereal-timeattitudeestimationwithexcellentconvergence.
KEYWORDS:Nonlinearcomplementaryobserver,attitudeestimation,IMU,real-timeimplementation,small-scaleflyingrobots.
SeparabilityAnalysisforMultipleFaultsinGNSS/INSIntegrationJinlingWang,YoulongWuandMuwaffaqAlqurashiSchoolofSurveyingandGeospatialEngineeringUniversityofNewSouthWalesSydney,NSW2052AustraliaEmail:Jinling.
Wang@unsw.
edu.
auFax:+61293137493ABSTRACTGlobalNavigationSatelliteSystem(GNSS)sensorshavebeenwidelyusedformanyapplicationstoprovideposition,velocityandtiming(PNT)informationwithhighprecision.
However,underharshoperatingenvironments,duetothesignalstrengthattenuationoreventemporarylossesofrangingsignalsespeciallyinurbanandvegetativeenvironments,GNSSsensorscannotprovidereliableandcontinuousPNTinformationatanytime.
Incontrast,withoutexternalsignals,anInertialNavigationSystem(INS)sensorisabletoofferafullnavigationintermsofposition,velocity,andattitude.
However,theaccuracyofinertialnavigationsolutionsdecreasessignificantlywithtime.
Thus,anintegratedGNSS/INSsystemcanovercometheshortcomingsofeachindividualsub-systemtoimprovetheavailabilityandreliabilityofthefullnavigationsolutionsforavarietyofuserplatformsinsuchareasasmachineguidance,control,autonomousdriving,aswellasgeospatialmapping.
IntheintegrationofGNSSandinertialsensors,anypotentialsensorfailuresorfaultymeasurementsduetoharshoperatingenvironmentsormalfunctionsofsensorcomponentsmayresultinpoorlyestimatednavigationparameters.
Ifthesensorcomponentfailuresorfaultymeasurementsoccurandcannotbedetectedimmediately,overallsystemperformanceswilldedegraded.
Thus,realtimedetectionoffailuresinestimationssystemiscriticallyimportant,particularlyforsomesafetyorliability-criticalapplications.
Therefore,itiscertainlynecessarytoimplementanonlinefaultdetectionandisolation(FDI)algorithm.
Variousapproachesoffaultdetectionandisolationhavebeenproposedandimplemented,andatthesametime,theMinimumDetectableBiases(MDBs)intheGNSS/INSintegrationandtheimpactoftheseMDBsontheestimatednavigationparameterscanalsobedefined.
However,inordertoidentifyandremovethespecificfaultymeasurements,thesystemshouldhavetheabilitytoseparatethesefaults.
Suchfaultseparabilityanalysisforsinglefaultscenariohasbeenextensivelyinvestigated,whilethethemultiplefaultseparabilityanalysisisstilllacking.
Therecentstudieshaveshownthat,comparedwiththesituationinsinglefaultscenarios,thecorrelationrelationshipsbetweenthedetection/identificationstatisticsfortwogroupsofmultiplefaultsarequitecomplicatedandrelativelylessunderstood.
ThispaperwillpresentthelatestseparabilityanalysisformultiplefaultscenarioswithintheGNSS/INSintegration,whichisofimportanceindevelopingfuturerobustpositioningandnavigationsystemswiththefaultdetectionandisolationprocedures.
KEYWORDS:,QualityControl,GNSS,INS,Integration,FaultDetectionandIsolationSession6CLandNavigation1110-1250PerformanceofGNSSSpeedMeasurementforEvidentiaryPurposesAndriyDyukov(1)TransportCertificationAustralia+61386014600andriyd@tca.
gov.
auShaunTalko(2)TransportCertificationAustralia+61386014600shaunt@tca.
gov.
auABSTRACTGlobalNavigationSatelliteSystems(GNSS)inparticulartheGlobalPositioningSystem(GPS)arecorepositioningtechnologiesusedintelematicsapplications.
GNSSisbeingusedbeyondthetraditionalpositioning,navigationandtimingdomainsandisemergingasasystemfordeterminingvehiclespeed.
HowevernotallGNSSbasedsystemsperformequallyandtheaccuracyindeterminingvehiclespeedisnotconsistentacrossdifferenttelematicplatformsespeciallyforevidentiarypurposes.
TransportCertificationAustralia(TCA)testsGNSS-basedtelematicssolutionsfortheperformanceofspeedagainstnationalstandardstoprovideuserswiththeconsistencyandconfidenceinthereportingofspeed.
ThispaperexploresthemeasurementanduseofspeedbasedonGNSS.
KEYWORDS:GlobalNavigationSatelliteSystems(GNSS);GlobalPosiitioningSystem(GPS);Speed;TransportCertificationAustralia;RegulatoryTelematics;evidentiary;certification.
ImprovingtheLowCostINS/GNSSSolutionUsingCooperativePositioningandRobustDynamicModellingTechniquesAzmirHasnurRabiain(1)TheUniversityofMelbourne,Australia+61431729103azmirhr@unimelb.
edu.
auAllisonKealy(2)TheUniversityofMelbourne,Australia+61383446804a.
kealy@unimelb.
edu.
auMarkMorelande(3)TheUniversityofMelbourne,Australia+61383444672mrmore@unimelb.
edu.
auABSTRACTMaintainingtheavailabilityofapositionsolutionisasignificantchallengeformanyapplicationssuchasintelligenttransportationsystems(ITS),locationbasedservices(LBS)andcollisionavoidancesystem.
GlobalNavigationSatelliteSystems(GNSS)aretheprimarytechnologyformeetingpositioningrequirementsformanyapplications.
GNSSenableuserstosolvefortheirpositionsataglobalscalebutitsavailabilitycanbelimitedinurbanandotherenvironmentswheresatellitevisibilityispartiallyorcompletelyobscured.
Toprovideforcontinuouspositioning,lowcostMEMSInertialNavigationSystem(INS)canbeemployedtobridgeGNSSgaps.
However,MEMSINSareknowntoproducelargeerrorswhenGNSSgapsoccuroverevenshorttimeperiods(morethan30secondsforexample),tothepointthatitismeaninglessforcriticalapplicationssuchascollisionavoidanceandhazardwarningsystems.
Thispaperproposestwotechniquestotacklethisissue.
Thefirst,isbyemployingtheCooperativePositioning(CP)techniquewherevehicleswithinavehicularadhocnetwork(VANET)areabletosharerelativepositioninginformationwhichwouldinturn,improvetheirpositioningsolutions.
Secondly,thispaperpresentsanewdynamicmodelforcombiningGNSSandINSmeasurements,specificallyforlandbasedvehicles.
ThenewmodelisabletoprovidebetterpositioningestimatesandiscomputationallylessexpensivecomparedtoconventionalKalmanfiltertechniques.
DatasetsobtainedfromapracticalexperimentcoordinatedundertheInternationalAssociationofGeodesy-Commission4andtheInternationalFederationofSurveyors–Commission5havebeenusedtovalidatetheaforementionedtechniques.
TheresultsindicatetheproposedtechniqueoutperformstheconventionalstandaloneINS/GNSSintegratedsystem,particularlyduringlong(afewminutes)GNSSoutages,whichisbeneficialparticularlyinGNSSdeniedareas.
KEYWORDS:INS/GNSSintegratedsystem;CooperativePositioning;INSModelling;UbiquitousPositioning;LandMobileApplicationsFieldandLabTestResultsofVehiclePositioningSystemsinWeakGNSSSignalsEnvironmentsUsingaMulti-channelSignalGeneratorOliverMichler,ChairofTransportSystemInformationTechnology/FullProfessor,TUDresden,Germanyoliver.
michler@tu-dresden.
de,Tel.
+4935146336841,Fax.
+493514636782RobertRichter,ChairofTransportSystemInformationTechnology/ResearchAssistant,,TUDresden,Germanyrobert.
richter@tu-dresden.
de,Tel.
+4935146336842,Fax.
+493514636782GeorgFrsterFraunhoferIVI,Locating,InformationandCommunication,Dresdengeorg.
foerster@ivi.
fraunhofer.
de,Tel.
+493514640682,Fax.
+493514640803ABSTRACTForinternationaltransportsystems,vehiclelocalizationbasedonGNSSisbecomingmoreandmoreessential.
ParticularlyforthetwoprimaryfreighttransportcarriersrailwayandwaterwaytransporttheaccuracyofGNSSissufficient,butforotherpurposes,suchassafety-relevantapplications,inner-terminallogisticsanddigitalizationofinfrastructures,moresophisticatedsystemscapableoftrack-sharplocatingarenecessary.
Infuture,thosesystemswillseamlesslycombineGNSSwithinfrastructure-basedlocalization.
Ifsuchsystemsaregoingtobeintroduced,oneproblemwillbetheneedforvalidandreliabletestandevaluationprocedures.
Itisparticularlydifficultandextensivetoperformreproduciblefieldtrialsforthat.
InPiLoNav(PreciseandintegerLocalizationandNavigation)–aprojectfundedbytheGermangovernment–thisproblemisaddressed.
ItdealswiththeevaluationofGNSS-basedlocatingsystemsintherailwayandinlandshippingsectorusingamulti-channelradiofrequency(RF)signalradiorecorderandgeneratorsystem.
ThisRF-testenvironmentcanbeusedtorecordortogenerate,respectively,variousGNSSantennasignals(e.
g.
GPS,GLONASS,partiallyGalileo)synchronously.
ThisallowsstoringcharacteristicGNSSRFenvironmentsoftypicalscenariosasanIQ-DatabaseandreproducingthemforlaboratoryGNSSreceivertestsanynumberoftimes.
Therailwayfieldtrialsaddressedweaksatellitenavigationsignalsinenvironmentslikeonesided/twosidedshadowingthroughforests,buildingsandcliffsorpassingofbridges,tunnels,rockgalleriesandtrainstations.
Incomparisontothattheinlandwaterfieldtrialsaddressedweaksatellitenavigationsignalslikepassingofbridges,usinglocksandlandinginports.
Additionally,inertialsensordataandvideodatacanbestoredwithinthesameprocess.
Thismakesitveryefficienttoevaluatenewtechnologies(e.
g.
receivers,locatingdatafusionmethods,trackmatchingapproaches).
Thecontributiontotheconferencewillfocusontheexperimentaldesign,thetechnicalconfigurationandstatisticallyevaluatingpositioningresultsregardingtofieldtrialsintheEuropeanrailwayandwaterwaynetworks.
KEYWORDS:GNSSfieldtest,GNSSmulti-channelsignalgenerator,receiverevaluationADesignofCarrier-SmoothedGPS/DRIntegrationSystemforTwo-DimensionalPreciseVehicleTrajectoryEstimationKyu-JinLeeDepartmentofInformationandCommunicationEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-6807,Fax:+82-42-824-6807,likebasic@naver.
comJeong-MinLimDepartmentofInformationandCommunicationEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-6807,Fax:+82-42-824-6807,likebasic@naver.
comTae-KyungSungDivisionofElectricandComputerEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-5660,Fax:+82-42-824-6807,tksaint@cnu.
ac.
krABSTRACTUsingcarrierphaseaswellascodemeasurementsfromGPSsatellites,wecanobtainaprecisepositionorsmoothedtrajectory.
Ifthereal-valuedintegerambiguitiesincarriermeasurementsareestimatedusingsingleepochcodemeasurementsattheinitialstate,precisetrajectorywithbiascanbeobtainedassumingthatcycleslipsdonottakeplaceandsatellitesetisunchanged.
Therefore,inordertogetprecisetrajectoryinrealapplicationusingCSGPS(Carrier-SmoothedGPS),thechangeinpositionbiasshouldbecarefullymonitoredandcompensated.
Ontheotherhand,DR(deadreckoning)navigationhasanexcellentshort-termaccuracytoprovidepreciserelativepositionandattitude.
ButDRsensorerrorsareaccumulatedinthecomputation.
Asaresult,thepositionandattitudeerrorsincreaseexponentiallyifitisnotproperlycalibrated.
IftheCSGPSandDRareintegratedtogether,real-timeprecisetrajectoryestimationispossibleevenwhencycleslipsexistincarriermeasurements.
ThispaperpresentsaCSGPS/DRintegrationsystemfortwo-dimensionalprecisevehicletrajectoryestimation.
MEMSgyro,accelerometer,andodometerareusedforDRsystem.
UsingtheDRmeasurements,cycleslipsincarriermeasurementsaremonitoredandcompensatediftheyhappen.
Moreover,whenthevisiblesatellitesetischanged,real-valuedintegerambiguitiesarerecomputedtoguaranteethetrajectorycontinuity.
Also,DRsensorerrorsaswellasvehiclepositionandheadingareestimatedusingcarriermeasurementsconversely.
Byfieldexperiments,performanceoftheproposedintegratedsystemwillbeverified.
KEYWORDS:Carrier-SmoothedGPS,Deadreckoning,Cycle-slip,Vehicletrajectory,Session7AGNSSReceiverHardware1–Developments1350-1530MonolithicIntegratedRFFrontEndsforMulti-GNSSReceiversK.
J.
Parkinson(1)E.
Glennon(2)NagarajC.
Shivaramaiah(3)AndrewG.
Dempster(4)ChrisRizos(5)SchoolofSurveyingandSpatialInformationSystems,UniversityofNewSouthWales,Sydney,2052,AustraliaEmailforcorrespondingauthor:k.
parkinson@student.
unsw.
edu.
auABSTRACTThecontinuingexpansionofavailableGNSSsignalsisanincreasingchallengeforreceiverdesigners.
NewsignalswithexpandedbandwidthsaredemandinggreatersamplingratesthatrequirecarefuldesignofthereceiverRFsectiontomaximiseperformancetradeoffs.
Ahighlevelofintegrationisrequiredtopreservesignalpathintegrityandminimisenoisewhilekeepingpowerconsumptiontoaminimum.
ThedesignofthefrequencyplanandthechoiceofIFbandwidtharecriticaltooverallreceiverperformance.
ThispaperdescribesthedevelopmentofthemonolithicRFfrontendchipsusedinthenewNamurumulti-GNSSreceiversatUNSW.
AnalysisofthesystemrequirementsandarchitecturedesignarediscussedincludingtheLNA,Mixer,IFAmplifierthroughtotheA/Dconverter.
There-configurabledesignprovidesfrequencyplanandsignalselectionflexibilityusinganintegratedsynthesiserandprogrammablebandwidthfilter.
Thedesignchallengesofthenewfrontendchipsarediscussedincludingfeaturesaimedatdeliveringgreaterperformanceandflexibility.
KEYWORDS:Namuru,Receiver,FPGA,RFFEProjectBiarriandtheNamuruV3.
2SpaceborneGPSReceiverEamonnP.
Glennon(1),KevinJ.
Parkinson(2),MazherChoudhury(3),JosephP.
Gauthier(4),andAndrewG.
Dempster(5)SchoolofSurveyingandGeospatialEngineering,TheUniversityofNewSouthWalese.
glennon@unsw.
edu.
au,kevin@dynamics.
co.
nz,joseph.
gauthier@student.
unsw.
edu.
au;a.
dempster@unsw.
edu.
auABSTRACTTheNamuruV3.
2GPSreceiverisanAustraliandevelopedFPGA-basedGPSreceiverdesignedspecificallyfortheBiarriProject;amulti-lateralColony2cubesatdefenceprojectthatAustraliaisparticipatinginviatheDefenceScienceandTechnologyOrganisation.
InthispaperabriefintroductiontotheBiarrimissionrequirementsisprovided,asarethevariousdesignfeaturesofthereceiverthathasbeendevelopedtosatisfythoserequirements.
Inparticular,wefocusondescribingthefeaturesrelatingtooperationofthereceiverinlow-earthorbit,in-orbitreprogrammingofthereceiver,highaccuracyrelativepositioningusingcarrierphaseandtheprovisionofprecisetimingsignals.
GPSsimulatortestresultsusingthelatestgenerationofNamuruV3.
2receiverarealsopresented.
KEYWORDS:Cubesat,GPSreceiver,FPGA,Colony2NamuruGNSSReceiverDevelopmentatUNSWK.
J.
Parkinson(1)E.
Glennon(2)NagarajC.
Shivaramaiah(2)AndrewG.
Dempster(3)ChrisRizos(4)SchoolofSurveyingandSpatialInformationSystems,UniversityofNewSouthWales,Sydney,2052,AustraliaEmailforcorrespondingauthor:k.
parkinson@student.
unsw.
edu.
auABSTRACTTheUNSWNamuruFieldProgrammableGateArray(FPGA)basedGPSreceivers,developedoriginallyin2004,havebeendeployedintomanyorganisationsworldwideandusedasavaluableopensourceGNSSresearchplatform.
OriginallydesignedfortheL1/L2signals,theNamurureceivershavecontinuedtodevelopfurtherasGNSSresearchhasprogressed.
WiththeavailabilityofnewGNSSsignalsandaugmentationsystemsnewmulti-GNSSversionsofthereceiverhavebeendevelopedatUNSWtoaccessthosesignals.
ThereceiverdesignsconsistofcustomdesignedRFfrontendchips,printedcircuitboards,base-bandlogicinanFPGAandapplicationfirmware.
ThispaperdescribesthedirectionanddevelopmentpathoftheNamurureceivers,includinganinsightintotheRFfrontendsdesignedtoexpandreceiverbandwidthandsignalaccess.
Thearchitectureanddesignchallengesofthenewreceivermodelsarediscussedwithfeaturesaimedatdeliveringgreaterperformanceandflexibility.
KEYWORDS:Namuru,Receiver,FPGA,Base-band,RFFEGalileoIOVSatellitesReceiverDevelopmentJinghuiWu*MazherChoudhuryJoonWaynCheongNagarajCShivaramaiahAndrewGDempsterAustralianCentreforSpaceEngineeringResearch,UNSW,AustraliaPh:+61(2)93854206/Fax:+61(2)93137493/email:jinghui.
wu@unsw.
edu.
auABSTRACTThefirstfouroperationalGalileosatelliteswerelaunchedon21October2011and12October2012andwillplayanimportantroleasakernelofthefullGalileosatelliteconstellation.
ThesuccessofreceivinganddecodingtherealGalileoIOVPFMsatellitesignalsalongwiththeGPSsignalsenablestheuseofGPS+Galileointegratedreceivers.
ThispapershowshowourGalileoE1receiverhasbeendevelopedtoprocessthereal-timeGalileosignalsbroadcastedfromtheoperationalIOVPFMsatellites.
TheNavigationMessagewascorrectlydecodedfromtheliveGalileosignalswhichenableGPS/Galileointegrationpositioninginrealtime.
AMatlabsoftwareversionandanFPGA-basedreal-timereceiverhavebeenusedforsimultaneousacquisitionandtrackingofGPS+Galileosignals.
Theperformanceinstaticmodewasdemonstratedthroughcode-phasemeasurementaswellaszero-baselinedoubledifferencecarrier-phasemeasurements.
KEYWORDS:Galileo+GPS,Acquisition,Tracking,Decoding,MeasurementSession7BIndoorPositioning11350-1530ANewApproachtoModelWi-FiSignalStrengthLinaChenCollegeofMathematics,PhysicsandInformationEngineering,ZhejiangNormalUniversity,China;SchoolofSurveyingandGeospatialEngineering,UNSW+86-579-82282501,chenlina@zjnu.
edu.
cnBinghaoLiSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854189,Binghao.
li@unsw.
edu.
auAndrewDempsterSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93856890,a.
dempsteri@unsw.
edu.
auABSTRACTFingerprintingisawidelyusedtechniqueforindoorpositioning,especiallyforWi-Fipositioningsystems.
Itisessentialtocreatethefingerprintdatabaseintrainingphase.
Aquicksurveycansavelaboureffortandtime;howeveritnormallymeansthesacrificeofthepositioningaccuracysinceasmallnumberofmeasurementthesignalstrengthcan'trepresenttherealsignaldistributionwellwithcurrentmodelsateachreferencepoints.
Inordertoachievehighaccuracy,abettermodelisrequired.
AnewmodelisproposedinthispaperusingtheDouble-PeaksGaussfunctiontoapproximatetheWi-Fisignalstrengthdistributionintheofflinetrainingphase.
Themodelwascreatedbasedontheanalysingoflargeamountmeasurementduringtheintensiveexperiments.
Testingshowsthismodelworkedwelleventhesampleschangedfrom10000to100.
Themodelcanbeusedtoimprovetheefficiencytogeneratetheradiomap.
Thenewmodelcanpossiblybeappliedtoothertypesofwirelesssignal.
KEYWORDS:fingerprinting;radiomap;signalstrengthAOutlierDetectionalgorithmforRSSI-basedMLestimationinWirelessSensorNetworksWonjuLeeDepartmentofElectricalEngineering,KoreaAdvancedInstituteofScienceandTechnology,RepublicofKOREAPhone:+82-42-350-7522,Fax:+82-42-350-7622,Email:na5208@kaist.
ac.
krJoonhyukKangDepartmentofElectricalEngineering,KoreaAdvancedInstituteofScienceandTechnology,RepublicofKOREAPhone:+82-42-350-7522,Fax:+82-42-350-7622,Email:jhkang@ee.
kaist.
ac.
krABSTRACTInthesedays,targetlocalizationisimportantapplicationinwirelesssensornetworks.
Severallocationestimationmethods;timeofarrival-,timedifferenceofarrival-,angleofarrival-basedlocationestimationmethods,performgoodestimationaccuracy,however,thesemethodsbecomeworseasthenumberofmovingobjectincreasing.
Therefore,thereceivedsignalstrengthindicator-based(RSSI)localizationschemewithmaximumlikelihood(ML)estimationtechniqueisproposed,andwhichhasgoodlocalizationperformanceeventhoughmultipathfadingandshadowingeffectsexist.
Inotherhand,whentherearesomeoutliersoveranchornode,itiswellknownthatthelocalizationperformancebecomespoor.
Inordertoimprovetheestimationaccuracy,theproposedalgorithmefficientlydetectstheoutlierovereachanchornodebyusingextremestudentizeddeviatetestandestimatesthetargetnodelocation.
Fromsimulationresults,weshowtheestimationaccuracyofproposedalgorithmisbetterthanthatofconventionallocalizationalgorithm.
KEYWORDS:Wirelesssensornetworks,Localization,RSSI-basedMLestimation,Outlierdetection,Extremestudentizeddeviatetest.
UsingBarometertoDeterminetheHeightforIndoorPositioningBinghaoLiSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854189,binghao.
li@unsw.
edu.
auBruceHarveySchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854178,b.
harvey@unsw.
edu.
auThomasGallagherSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854208,t.
gallagher@unsw.
edu.
auABSTRACTIthasbeenobservedthatatmosphericpressuredecreasewhenthealtitudeincreases.
Modelshavebeencreatedtorelateheighttopressure.
Abarometercanmeasuretheairpressureandthenthealtitudecanbecalculated.
BeforetheeraofGNSS,barometerwaswidelyusedtodetermineheightsoutdoors.
TheinventionofGNSSwasarevolutioninpositioningandnavigation.
However,itdoesnotworkinindoorenvironment.
AlternativetechnologieshavebeendevelopedsuchasWi-Fifingerprintingmainlyfor2Dpositioningandnavigation.
Insomeoftheapplications,3Dor2.
5D(thelevelofthebuilding)isrequired.
Usingbarometerisapossiblesolutionandsomenewmobilephoneshaveabuildinpressuresensor.
Buttheretoomanyissuesshouldbeconsidered.
IsheightdeterminedfrombarometeraccurateenoughIstherealatencyproblemDoestheairconditioninginanalmostsealedbuildingsignificantlyaffectheightreadingsThispaperdiscussesthenecessaryconsiderationstousebarometersforindoorapplicationsbasedonexperiments.
Possiblesolutionsaresuggested.
KEYWORDS:Barometer;Indoorpositioning;AltitudeHyperbolicPositioningwithProximateMulti-channelPseudoliteforIndoorLocalizationYoshihiroSakamotoDept.
ofModernMechanicalEngineering,WasedaUniversity,Japanphone:+81-3-5286-3264,fax:+81-3-5272-0948,email:yoshi@aoni.
waseda.
jpHiroakiArieDept.
ofIntermediaArtandScience,WasedaUniversity,Japanphone:+81-3-5286-2742,fax:+81-3-5286-2742,email:arie@aoni.
waseda.
jpTakujiEbinumaDept.
ofAeronauticsandAstronautics,theUniversityofTokyo,Japanphone:+81-3-5841-6972,fax:+81-3-5841-6976,email:ebinuma@nsat.
t.
u-tokyo.
ac.
jpKenjirouFujiiHitachiIndustrialEquipmentSystemsCo.
,Ltd.
,Japanphone:+81-3-4345-6011,fax:+81-3-4345-6913,email:fujii-kenjirou@hitachi-ies.
co.
jpShigekiSuganoDept.
ofModernMechanicalEngineering,WasedaUniversity,Japanphone:+81-3-5286-3264,fax:+81-3-5272-0948,email:sugano@waseda.
jpABSTRACTThecarrier-phase-basedpositioningwithGPSpseudoliteshaspotentialtoachievecentimetre-levelpositioningaccuracy.
However,sinceithasseveralinnateproblemssuchasthenear-farproblem,synchronization,andintegerambiguityresolution,itisdifficulttousepseudolitesforpracticalapplications,especiallyinnarrowindoorenvironments.
Inthepresentwork,inordertoavoidtheseproblems,anoveluseofpseudoliteisintroduced.
Threepseudoliteantennasarelocatedatintervalsof95mm(halfwavelengthoftheGPSL1carrierwave)similartoanantennaarray,andthoseantennastransmitcarrierwavesthataresynchronizedtoeachother.
Thereceiver(anoff-the-shelfGPSreceiverwhosefirmwareismodified)detectsthephasedifferencesbetweenthecarrierwaves,andcalculatesitspositionusingahyperbolicpositioningmethod.
Positioningexperimentstoevaluatetheproposedmethodareconductedintwodifferentindoorplaces.
Theresultsoftheexperimentsshowthatpositioningaccuracyoflessthanonemetreispossibleifthedistancebetweenthereceiverandpseudoliteantennasislessthanaboutthreemetres.
Althoughthisaccuracyisworsethanthecentimetre-levelaccuracyaimedat(butpracticallynotachieved)byconventionalpseudolites,theproposedmethodcanavoidmajorproblemsofpseudolites;thatis,itopensupnewpossibilityforindoorpositioningapplicationsKEYWORDS:hyperbolicpositioning,pseudolite,indoorGPSSession7CDatumsandGeodesy1350-1530MonitoringStationMovementusingaState-WideSimultaneous'AdjustmentofEverything'ImplicationsforaNext-GenerationAustralianDatumJoelHaasdykSurveyInfrastructureandGeodesy,LandandPropertyInformationNSWDepartmentofFinance&Services,BathurstNSW2795,AustraliaTel:+61263328485,Fax:+61263328479,Email:Joel.
Haasdyk@lpi.
nsw.
gov.
auCraigRobertsSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,SydneyNSW2052,AustraliaTel:+61293854464,Fax:+61293137493,Email:c.
roberts@unsw.
edu.
auABSTRACTTheestablishmentofanext-generationAustraliandatumiscurrentlybeinginvestigated.
Suchdatumupdateisrequiredtoaccommodatetheincreasingaccuracyandimprovedspatialandtemporalresolutionavailablefrommodernpositioningtechnologiestoanever-broadeninguserbase.
Whilethespatialcommunitydebatesthecosts,benefitsandoptimumimplementationofanewdatum,eachAustralianstateandjurisdictioniscurrentlypreparingadatasetcontainingallavailablegeodeticmeasurementsfromtheirarchives.
Newcomputingtechnologiesmeanthatstate-wideandevennation-wideadjustmentsarenowroutinelypossiblewithanessentiallyunlimitednumberofstationsandmeasurements,whilenewmeasurementscanbeincorporatedimmediatelywhentheyareavailable.
ThisstudydiscussestheopportunitiesandlimitationsofasimultaneousadjustmentofallavailableGNSSmeasurementsformonitoringthemovementofgeodeticsurveystations.
TwocasestudiesinNSWarepresentedtohighlightthedifferentimplicationsoflandmovementversusstationinstabilityonpotentialdatumdeformationmodelsinthevicinityofthesestations.
Additionalmeasurementsvia'crowd-sourcing'methodologieswouldhelptomaintainthecurrencyandrelevanceofthedatum,whiletraditionallynon-geodetictechniquessuchasDInSARwouldbeinvaluableindefiningtheextentofanydetecteddeformation.
Theresultspresentedherearepreliminaryandaimtohighlightareasofpotentialresearch,andpromotediscussionregardingdatumupdateinthewiderspatialcommunity.
KEYWORDS:data-mining,Datum,deformation,geodesy,GNSSDeterminingNationalVerticalDatumbyGPSBuoyPo-HsienHsu(1)DepartmentofAppliedGeoinformatics,ChiaNanUniversityofPharmacyandScience,TaiwanR.
O.
C.
6-2664911&6-2666114,phhsu1688@mail.
chna.
edu.
twChing-LiangTseng(2)DepartmentofEarthSciences,NationalCheng-KungUniversity,TaiwanR.
O.
C.
6-2613614&6-2666114,tsengcl1155@gmail.
comABSTRACTUsually,tomaintainthenationalverticaldatumofTaiwanisbasedonthesupportoftidalgaugethatprovidesanaccurateandpreciseheightrecord.
Ideally,theheightoftheprimarytidalbenchmarklocatedonthestablesolidearthisbasedontheresultobtainedfromthelongtermtidalgaugerecordanditcanbereferredtoallbenchmarksaroundtheisland.
However,theheightdifferencebetweenthetidalgaugeandprimarytidalbenchmarkisrelative.
Ontheotherhand,theheightisreferredtolocaldatum.
Fromglobalpointofview,itshouldbetransformedtoglobalcoordinatesystembysatellitegeodesyorphysicalgeodesy.
Sincethetechniqueofspacegeodesyhasbeendevelopedrapidly,itcanachieveabsolutesealevelaccurately.
Therefore,asuitableGPSbuoywasdesigned.
Itwasdriftontheseasurfaceneartidalgaugetomonitortheheightofseasurfaceinglobalcoordinatesystem.
Itcansolvetheproblemsoflocaldatumandunstabletectonicplatesandsubductionzones.
SincetheantennasofGPScannotcontinuouslyperpendiculartotheseasurfaceduetoupanddownofthewave,thebuoygesturemustbesolvedout.
Accordingtotheresultcollectedfromtheharborneartidalgaugeforthreedays,theaccuracyofthezeropointofthesealevelisabout5mm~7mm.
ItisclearthatGPSbuoycanbeausefultooltoachievetheverticaldatuminglobalpointofview.
KEYWORDS:tidalgauge,GPSbuoy,ellipsoidheight,TGGSstation,altitudeangleVictoria'sGeodeticStrategy–OngoingDevelopmentsinLightofGeodeticInfrastructurePriorities,ChallengesandOpportunitiesDrRogerFraserDepartmentofEnvironmentandPrimaryIndustries,Victoria,Australia+61386362551,roger.
fraser@dse.
vic.
gov.
auHaydenAsmussenDepartmentofEnvironmentandPrimaryIndustries,Victoria,Australia+61386362374,hayden.
asmussen@dse.
vic.
gov.
auABSTRACTFundamentaltothesustainabledevelopmentofVictoriaistheavailabilityofareliable,highaccuracygeodeticreferencingsystemuponwhichspatialinformationcanbebased.
TheauthoritativereferencingsysteminAustraliaistheNationalGeospatialReferenceSystem(NGRS).
Likeotherfundamentalinfrastructure,theNGRSrequiresongoingdevelopmentandmaintenancetoensurethatitcontinuestomeetthepurposeforwhichithasbeenestablished.
IntheVictoriancontext,thedevelopmentandmaintenanceoftheNGRSstandsuponseveralcriticalinfrastructurecomponentsincludinganintegratednetworkofGlobalNavigationSatelliteSystem(GNSS)ContinuouslyOperatingReferenceStations(CORS)andconventionalsurveycontrolmarks;alargenumberofgeodeticmeasurements;avastamountofinformationaboutGNSSCORS,marksandmeasurements;hardware,databasemanagementsystemsandsoftware;andvariouspolicies,standardsandguidelines.
Inresponsetorecognisedtrendsinvarioussocietal,environmental,scientificandeconomicprioritiesandchallenges,DEPIispursuinganumberofstrategicobjectivesforthemaintenanceofVictoria'sgeodeticinfrastructureoverthenextfiveyears.
ThispresentationreviewsthesestrategicobjectivesanddiscussessomeopportunitiesforthewayinwhichAustralia'sgeodeticdatumismaintained.
KEYWORDS:Geodeticstrategy,GNSS,datum,infrastructure,information.
Session8AGNSSReceiverHardwareII–Performance1600-1740PerformanceEvaluationofaGPSReceiverwithVDFLLinHarshEnvironmentsDeokWonLimSatelliteNavigationTeam,KoreaAerospaceResearchInstitute,Korea+82-42-870-3978,+82-42-860-2789,dwlim@kari.
re.
krHeonHoChoiDepartmentofElectronicsEngineering,ChungnamNationalUniversity,Korea+82-42-825-3991,+82-42-823-4494,heonho@cnu.
ac.
krSangJeongLeeDepartmentofElectronicsEngineering,ChungnamNationalUniversity,Korea+82-42-825-3991,+82-42-823-4494,eesjl@cnu.
ac.
krMoonBeomHeoSatelliteNavigationTeam,KoreaAerospaceResearchInstitute,Korea+82-42-860-2266,+82-42-860-2789,hmb@kari.
re.
krABSTRACTTheproblemofdesigningrobustarchitecturestotrackglobalnavigationsatellitesystem(GNSS)signalsinharshenvironmentshasgainedhighattention.
Theclassicalclosedlooparchitecturessuchasdelaylockedloops(DLL)andfrequencylockedloops(FLL)havebeenusedformanyyearsfortracking,butinchallengingapplicationssuchasblockageofsignalsandthepresenceofmultipath,theirdesignprocedurebecomesintricate.
Asoneofthealternativearchitecture,thereisthevectortrackingtechniquewhichisabletoimprovetheGNSSavailabilityinsuchsignalenvironments.
Thispaper,therefore,describesanapproachtoimplementavectordelayandfrequencylockedloop(VDFLL)inaconventionalGPSreceiver.
Thearchitectureofthisapproachwillbedescribedindetailandthepotentialcapabilitieswillbeshownbytheresultsofexperimentsinurbanandsuburbanareas.
Fortheseexperiments,apairoflowcostGPSreceiverswasalsodeployedtoassesstheaccuracyincommercialdomain.
Thedatafromthesereceiverswaspost-processedforfurtherreasoningandconclusions.
Theanalysisofthisdatademonstratedthattheperformanceoftheproposedarchitecturehasbeenimprovedfortheharshsignalconditionsduetotheblockageofsignalsandthepresenceofmultipath.
KEYWORDS:GNSS,VectorTracking,SignalBlockage,MultipathAnalysisofPerformanceDegradationDuetoRFImpairmentsinQuadratureBandpassSamplingGNSSReceiversVaidhyaMookiah,EdizCetin,AndrewG.
DempsterUniversityofNewSouthWales,AustraliaTel:+61415823738e-mail:v.
mookiah@student.
unsw.
edu.
au,e.
cetin@unsw.
edu.
au,a.
dempster@unsw.
edu.
auABSTRACTRadioreceiverarchitectureswithAnalogtoDigitalConverter(ADC)closetotheantennacanperformreconfigurablebandselectioninthedigitaldomain,improvingperformance.
TechniquessuchasBandpassSampling(BPS)requireasamplingrateofatleasttwicethebandwidthofsignaltosampleanddownconvertthereceivedsignal,whereasQuadratureBandpassSampling(QBPS)accomplishesthiswithhalfthesamplingrate,butfortwosamplesequences.
QBPSachievesfrequencydownconversionanddigitisationeliminatingtheneedforexpensiveanalogmixers,filtersandtheRadioFrequency(RF)impairmentsassociatedwiththem.
QBPSoperatesonthereceivedRFsignalandusingtwoADCswithsamplingclocksseparatedbyonequarterofthesignalcarrierperiod(1/fc4)relativetooneanother.
ForGPSL1signalsthisdelaycorrespondsto158.
69pswhichisnottrivialtogenerateaccurately.
ImpairmentsassociatedwithgeneratingthisdelayandthesignalpathsbetweentheADCsresultsinperformancedegradationinthereceiver.
ThispaperwillinvestigatetheinfluenceoftheRFimpairmentsassociatedwiththeQBPSschemeandwillcompareitsperformancewithdifferentclassicalRFfront-endarchitecturesforgeneratingin-phaseandquadraturesignalsintermsofImageRejectionRatio(IRR)andBitErrorRate(BER).
AquantitativecomparisonofarchitectureswillbeperformedusingsimulationcasestudiesinaMATLABenvironment.
TheproposedQBPSarchitectureperformancewithrespecttoRFimpairmentisbetterthanotherarchitecturesasiteliminatespowerhungryandnon-linearanalogcomponents.
Inaddition,thefeasibilityofQBPSforfrequencytranslationanddigitisingmultibandGNSSsignalswillalsobeexplored.
KEYWORDS:softwareradio,bandpasssampling,RFimpairment,imagerejectionratio,quadraturesampling.
InitialTestResultsofNamuruDual-GNSSSpacebornReceiverMazherChoudhury(1)*JoonWaynCheong(2)*JinghuiWu(3)*NagarajCShivaramaiah(4)*AndrewGDempster(5)**AustralianCentreforSpaceEngineeringResearch,UNSW,AustraliaPh:+61(2)93856702/Fax:+61(2)93137493/email:(1)mohammad.
choudhury@unsw.
edu.
auABSTRACTThispaperanalysesthetestresultsoftheperformanceevaluationoftheNamurudual-GNSSintegratedreceivercapableofhandlingbothGPSandGalileosimultaneously.
TheNamuruisadual-RFfrontendFPGAhardwareplatformdevelopedbyUniversityofNewSouthWales(Sydney,Australia)andGeneralDynamics(NewZealand)tosupportvariousresearchprojectsthatrequiresaccesstothesignal-processinglevelofaGNSSreceiver–afeaturethatisnotavailableinanyCommercialOfTheShelf(COTS)GNSSreceiver.
RecentimprovementsmadetotheNamurureceiverenableittoprocessnotonlyGPSsignalsbutalsoQZSSandGalileosignals.
TheNamurureceiverthatisstillunderdevelopmentspecificallytargetsspaceoperationssuchasanorbitingsatelliteatLowEarthOrbit.
Thespacescenarioconsideredisarealisticsetofformation-flyingLEOsatelliteswhereaccuraterelativepositioninformationiscruciallyrequired.
Thetestsperformedincludeasingle-spacecraftsingle-antennacaseforabsolutepositioning,asingle-spacecraftmulti-antennacaseforattitudedeterminationandadual-spacecraftcaseforrelativepositioning.
Tosatisfybothattitudedeterminationandrelativepositionngcases,carrierphasepositioningalgorithmsareemployed,whereaspseudorange-derivedpositionsolutionisusedtoachieveabsolutepositioning.
TheevaluationwasperformedusingaSpirentsimulator(GSS8800).
TheNMEAoutputstreamfromthereceiverwasprocessedusingMATLABandRtkLibtoproducepositionsolutionsthatwillbecomparedagainstSpirent-derivedtruthdata.
Preliminarytestresultsinorbitscenarioexhibitsthenavigationaccuracyof0.
2±10m,0.
60±5and2±7mforX,YandZrespectively.
Ontheotherhand,baselinesolutionpresentsaccuracyof0.
20±0.
8mfor3Dposition.
Furtherimprovementonpseudorangeaswellascarrierphasemeasurementsareunderdevelopment.
KEYWORDS:Namuru,GPS-Galileoreceiver,dual-GNSS.
InitialAssessmentofBeiDouAugmentedGNSSThomasMorleyNovAtel,Inc.
+1-403-730-4641thomas.
morley@novatel.
comRodMacLeodNovAtelAustraliaPtyLtd+61400883601rod.
macleod@novatel.
comABSTRACTTherecentreleaseoftheBeiDouICDhasallowedGNSSreceivermanufacturerstointegrateBeiDousignalsintotheirtrackingandpositioningalgorithms.
ThispresentationwillprovideanoverviewofNovAtel'sinitialobservationsoftheBeiDousignalperformanceandcharacteristics.
Additionally,thispresentationwillreviewreal-worldresultsofBeiDouaugmentationofGNSSpositionsolutions.
Datawerecollectedatvariouslocationswithintheareacoveredbytheregionalcomponent(geostationaryandinclinedgeosynchronoussatellites)oftheBeiDouconstellation.
TheBeiDousignalswerefoundtobereasonablycompatibletoGPSsignalsintermsofpseudorangeandcarrierphasequality.
PerformancedeltasduetotheinclusionofBeiDouinformationarenotedforvariouspositioningmodesincludingsinglepoint,GL1DEandRTKmodes.
Improvementstosolutionaccuracyandavailabilityaredemonstrated,particularlyforusersoperatinginanobstructedenvironment,suchassurfacemining.
Thispresentationconcludesthat,whenproperlyintegrated,theBeiDousignalswillbeavaluableenhancementtoaugmentedGNSSpositioning.
KEYWORDS:BeiDou,RTK,accuracy,availabilitySession8BIndoorPositioningII1600-1740AComparisonofAlgorithmsAdoptedinFingerprintingIndoorPositioningSystemsZhaoKaiLiBinghaoSchoolofSurveyingandSpatialInformationSystemsUniversityofNewSouthWalesSydney,Australia+61424420022kai.
zhao@unsw.
edu.
auABSTRACTFingerprintingtechnologyhasbeenwidelyusedinindoorpositioningsystemssuchasWi-Fipositioningsystems.
Itsperformancedependsonnotonlythemeasurementofsignalstrength,butalsothealgorithmused.
Inthispaper,anoverviewisgivenofthecurrentpopularalgorithmsadoptedinWi-Fiindoorpositioningsystem,includingdeterministicmethod(Knearestneighbour,Kweightnearestneighbour),probabilisticmethodandneuralnetwork.
Inordertogetreliableandrepresentativeresult,twodifferentsetofdataweretested.
Comprehensivecomparisonsweremadewithrespecttopositioningaccuracy,computingpowerrequirementandthecomplexityofcreatingthedatabase.
Furthermore,detailsofchoosingparametersandimplementationofthesealgorithmsarediscussed.
KEYWORDS:Indoorpositioning,FingerprintingMethod,AlgorithmUsingGeomagneticFieldforIndoorPositioningBinghaoLiSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854189,binghao.
li@unsw.
edu.
auThomasGallagherSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854208,t.
gallagher@unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854205,c.
rizos@unsw.
edu.
auAndrewG.
DempsterSchoolofSurveyingandGeospatialEngineering,UNSW+61-2-93854205,c.
rizos@unsw.
edu.
auABSTRACTGeomagneticfieldvariationsforindoorpositioningandnavigationhasattractattentionsrecentlybecauseoftheadvantagethatnoinfrastructureneedstobepre-deployed.
Testusingdelicatemagnetometershasshownitispossibletousegeomagneticfieldforpositioningpurposes.
However,therearestillissuestobeaddressedforrealapplications.
Forinstance,arethelowcostbuilt-inmagnetometersinmobilephonesgoodenoughforpositioningpurposebasedonfingerprintingtechnologyIsthegeomagneticfieldstableforaverylongtermFurthertestswerecarriedoutusingthelatestsmartphones.
Asusinggeomagneticfieldaloneforpositioningmayhavedifficulties,integrationwithothermethodisnecessary.
Wi-Fiisoneoftheobviousoptions.
Therearetwopossiblewaystocombinethesetwomethods:oneisatwostepsprocess,usingWi-Fitoestimatetheapproximatepositionfirst,andthenapplygeomagneticfiledtorefinetheestimation;theotheriscreatingafingerprintingdatabaseincludingWi-Fisignalstrengthelementsandgeomagneticfieldelements,acombinedfingerprintisusedtoestimatethepositiondirectly.
Algorithmsweredevelopedandtested.
KEYWORDS:Geomagnetic;Indoorpositioning;Fingerprinting"Simonsays":MobilityandIndoorNavigationforpersonswhoareBlindorVisionImpairedEuanRamsey-StewartRamseyStewartIndustrialDesign(RSID)Sydney,AustraliaP:+61289584774E:euan@unsw.
edu.
auBinghaoLiSchoolofCivilandEnvironmentalEngineering,UNSWSydney,AustraliaP:E:binghao.
li@unsw.
edu.
auThomasGallagherSchoolofCivilandEnvironmentalEngineering,UNSWSydney,AustraliaE:t.
gallagher@unsw.
edu.
auChrisRizosSchoolofCivilandEnvironmentalEngineering,UNSWSydney,AustraliaE:c.
rizos@unsw.
edu.
auHoecheeYamSchoolofCivilandEnvironmentalEngineering,UNSWSydney,AustraliaE:yam.
hoechee@gmail.
comABSTRACTPeoplewhoareBlindorVisionImpaired(BVI)arearguablyapartoftheworldcommunitythatcouldbenefitmostfromusingnavigationandlocationtechnologies.
Suchtechnologiesareabletochangeaperson'squalityoflifeinmanyways;providinghealth,socialinteractionemploymentandeconomicopportunities.
.
.
Alltoooftenthiscommunityisforgottenorgiveninadequateconsiderationwhendesigningnavigationorwayfindingsystems.
Thisisevidencedbyminimalnavigationsystemsuse,amongstBVIpersons.
Almost80%percentofourlivesarespentindoorsandGPSonlyprovidesaccuratepositioningoutdoors.
Thereisavoidtobefilled;theindoorenvironment.
Wehaveyet,todevelopatrulylow-cost,usableandcommerciallyviablesolutiontotheproblemofindoornavigationandpositioning.
TheBVIProjectteamattheUniversityofNewSouthWales(UNSW)hasbeenaddressingthissituation.
Theteamsetouttodeliveralowcostsolutiontotheindoornavigationproblem.
Byhypothesising,"IfBVIpersonscansafelynavigatethroughanunfamiliarindoorenvironment,thenalmostanyonecould.
"TheteamusedtheinformationneedsaswellasthemanymobilityandorientationperspectivesofBVIpersons,intheoveralldesignandsystemsolutioncalledSIMO(SimplifiedInformationforMobilityandOrientation).
TheUNSWteamconductedresearchthrough,interviewswithBVIpersonsandOrientationandMobilityexperts,surveys,phonequestionnairesandprototype/usertesting.
Theteamhasuncoveredanon-traditionalwayofexpressingspatialinformationandprovidesasolutionusinganewSmartPhoneAPP,internalIMU'sandWi-Fidetection.
FromthestarttheBVIcommunitywasconsultedbytheteamwhothroughuserexperiencedesignandincorporationofinclusivedesignprinciplesatalltimes,enabledabetterunderstandingofspecificandparticularorientationandmobilityneeds.
"Thinkingoutsidethebox",theUNSWBVIProjectteamhaveprovideauniquesolutiontotheproblemofIndoorNavigationandPositioningandinterfacedesign.
KEYWORDS:SIMO,IndoorNavigation,IndoorLocation,BlindorVisionImpaired,BVI,UserInterface,UserExperience,InclusiveDesignIndoorGPS,SimplifiedInformation,Mobility,Orientation.
IntegrationofPedestrianDRandBeacon-APbasedLocationSystemforIndoorNavigationJeong-MinLimDepartmentofInformationandCommunicationEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-6807,Fax:+82-42-824-6807,likebasic@cnu.
ac.
krSang-HoonYooDepartmentofInformationandCommunicationEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-6807,Fax:+82-42-824-6807,hoonkko@hanmail.
netKyu-JinLeeDepartmentofInformationandCommunicationEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-6807,Fax:+82-42-824-6807,lkj0136@cnu.
ac.
krTae-KyungSungDivisionofElectricandComputerEngineeringChungnamNationalUniversity,KoreaTel:+82-42-821-5660,Fax:+82-42-824-6807,tksaint@cnu.
ac.
krABSTRACTThoughtheglobalnavigationsatellitesystems(GNSS)arewidelyusedinvariouslocationbasedservices(LBS),itcanhardlybeusedindoorsduetosignalblockingormultipathfading.
ForindoorLBS,variouslocationsystemshavebeendevelopedandexamplesincludeWiFimultilateration,RFfingerprint,UWBWPAN,andpedestriandeadreckoning(PDR).
Owingtorapiddeploymentofthesmartphone,WiFilocationsystemsandPDRaremorehighlightedasacandidateofindoorlocationsolutionrecently.
BecauseWiFimultilaterationutilizedreceivedsignalstrengthindicator(RSSI)measurementinranging,itspositioningaccuracyissomewhatpoor.
ThoughtheperformanceofRFfingerprintisbetterthanthatofWiFimultilateration,itsperformanceissensitivetoRFenvironment.
Moreover,ifmanyaccesspoints(AP)areinstalledtoimprovetheirlocationperformance,interferencebetweenAPsbecomescriticalindatacommunication.
InthePDR,pedometeriscommonlyusedtomeasuredistanceandtheheadingdirectionisfoundusingmagnetometerand/orgyroscope.
Becausedeadreckoning(DR)sensorerrorsareaccumulatedinthecomputation,locationerrorofPDRincreasescumulativelyastimegoesifthepositionandheadingarenotcalibratedpeoperly.
Thispaperpresentsanovelindoornavigationsystemintegratingbeacon-typeAPandPDR.
Tominimizetheinterferenceandtofinduserpositionwithhighaccuracy,wedevelopedabeacon-typeAPthathasasmallfootprint.
Whenthebeacon-typeAPsareinstalledatthecrossroadandthefootprintofeachAPcoverseachdirectionofcorridor,smartphoneuserscaneasilyobtaintheirprecisepositionandmovingdirection.
Becausebeacon-typeAPhasasmallfootprint,PDRisusedtocomputeuserpositionbetweenthefootprintcoverageofbeacon-typeAP.
ComparingtheAPpositionandtheoutputofPDR,userpositionandheadingarecalibrated.
Moreover,pedometerscalefactorandgyrobiasareestimatedtoimprovetheperformanceofPDR.
Byfieldexperiments,performanceoftheproposedindoornavigationsystemwillbeverified.
KEYWORDS:PedestrianDR,Beacon-typeAP,IndoornavigationAPerformanceEvaluationoftheRFIDMethodinIndoorPositioningFingerprintingDatabaseCollectionandMaintenanceZhaoKaiLiBinghaoSchoolofSurveyingandSpatialInformationSystemsUniversityofNewSouthWalesSydney,Australia+61424420022kai.
zhao@unsw.
edu.
auABSTRACTFingerprintingtechnologyhasbeenwidelyusedinWi-Fiindoorpositioningsystems.
However,themajordisadvantageofthistechnology–therequirementtogenerateandmaintainthelocationfingerprintingdatabaseremains.
WehaveproposedanapproachtouseRadioFrequencyIdentification(RFID)technologytosignificantlysimplifytheprocessoflocationfingerprintingcollection.
Inthismethod,weusetheRFIDtagstomarkandrepresentthereferencepoints.
Anelectronicdevicecanbeusedtocollectfingerprintingdataautomaticallywhilepeoplecarryitwalkaround.
Thus,theprocessoffingerprintingdatacollectioncanbedonebythestaffslikesecurityguardsintheircommonpatrol.
WehavedevelopedanexperimentalsystemcalledGeniWi-Fi,totesttheproposedmethod.
Inthissystem,RFIDtagsweredesignedtobedeployedinthetargetenvironmentinadvance.
Theportablefingerprintingdatacollector,whichisthemainpartofthissystem,containsaRFIDreader,aWi-Fiscanner,aprocessorchipandamemorybar.
WhenpeoplecarrysuchcollectorandpassbytheRFIDtag,thereaderscansthetagandtriggerstheWi-FiscannertorecordtheWi-Fisignalstrength.
DataaresavedinthememorybaranduploadedtotheserverviaeitheraWi-Ficonnectionoraserialportlater.
Thedataarepostprocessedtogenerateorupdatethefingerprintingdatabase.
GeniWi-Fiwastestedincommonindoorenvironment.
Weanalysedtheimpactofdifferentfactorstothepositioningperformanceandtestedsomepotentialsolutionswhichcouldimprovetheaccuracy.
Theissuesofcompatibilitywiththecurrentfingerprintingpositingsystemsarealsodiscussed.
KEYWORDS:GeniWi-Fi,indoorpositioning,RFID,FingerprintingmethodSession8CGNSSInfrastructureI1600-1740NationalPositioningInfrastructure:WherearewenowGrantHauslerCooperativeResearchCentreforSpatialInformationTheUniversityofMelbourne,AustraliaTel:+61390353223Email:g.
hausler@student.
unimelb.
edu.
auABSTRACTSpatialorganisationsacrossAustraliahavebeenleadingthepushtodevelopaNationalPositioningInfrastructure(NPI)thatwilldeliveruniformaccesstoreliableandaccuratePosition,NavigationandTiming(PNT)information.
TheNPIwillbebasedontheacquisition,processinganddistributionofGlobalNavigationSatelliteSystem(GNSS)datathroughanetworkofContinuouslyOperationReferencesStations(CORSs).
CORSinfrastructureiscurrentlydeployedandoperatedindependentlyonanad-hocbasisbygovernmentsandindustryacrossAustralia.
Australia'sspatialcommunityhasidentifiedandrespondedtotheneedformoreefficientandcost-effectivemanagementofPNTinfrastructurebydefiningagreedprinciplesandstrategiesfortheNPI.
Collectively,theSpatialInformationCouncil's(ANZLIC's)NPIPolicy,theAustralianSpatialConsortium's(ASC's)StrategicPlanforGNSS,andtheNPIInfrastructurePlanpreparedbyGeoscienceAustraliaidentifyobjectivesandpriorityactionsaimedatlimitinginfrastructureduplicationandover-investment;implementingdataandservicestandards;improvingqualitycontrolmeasures;extendinguseraccess;providingredundancythroughnon-GNSStechnology;anddesigningaNPIthatsupportsthediversePNTneedsofallindustrysectors.
ThispaperprovidesasummaryofpastandpresentworktowardsestablishingtheNPIandindentifiesfuturechallengesforcommunicatingandrealisingitsbenefits.
PNTinitiativesthataimtoimproveuseraccessandserviceperformancebothdomesticallyandinternationallyareidentifiedtojustifywhytheNPIwillensureAustraliaremainscompetitiveinamulti-GNSSfuture.
KEYWORDS:NationalPositioningInfrastructure(NPI);GlobalNavigationSatelliteSystem(GNSS);ContinuouslyOperatingReferenceStation(CORS);Position,NavigationandTiming(PNT);ServiceLevelManagement(SLM).
ArchitectureProposalfortheOpenSourceGNSSReferenceServerv4AliSarwarSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854185,Fax:+61293137493Email:ali.
sarwar@student.
unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854205,Fax:+61293137493,Email:c.
rizos@unsw.
edu.
auABSTRACTMobilecommunicationsnetworkarchitectureischangingrapidly,leadingtochangesinend-useraccess,coreandpositioningnetworkelements.
Forexample,cellularnetworkcarriersmaybeincreasinglyconstrainedtoprovidingtransmissioncarriagepipes.
Thismeansthatmobilelocationbasedservertechnologieswillneedtoevolve.
ThescalableOpenSourceGNSSReferenceServer(OSGRS)isanimplementationofacontinuouslyoperatinglocationbasedreferenceserveroperatingattheUniversityofNewSouthWales.
Itisbasedonthefollowingelements:GNSSReferenceInterfaceProtocol(GRIP),ExtensibleMark-upLanguage(XML),NovatelOEM4chipset,NetworkedTransportofRTCM(RadioTechnicalCommissionforMaritimeServices)overInternetProtocol(NTRIP),LongTermEvolution(LTE)PositioningProtocolanditsextensions(LPP/e).
TheOSGRSsystemdevelopmenttimeline(2007-2013)ispresented.
ThispaperproposesafuturearchitectureofOSGRSthatwillsourceNTRIPinformationoveradifferentunderlyingnetwork.
Thenetworksub-systemcorewhichcontainsthepositioningunitsofServingMobileLocationCentre(SMLC)andGatewayMobileLocationCentre(GMLC)intheRadioAccessNetwork(RAN)willmergewithGeneralPacketRadioSwitching(GPRS).
TheSMLC-GMLCtogetherservethelocalisationrequestsofend-usersthroughLPP/ewheretheGPRSnetworkprovidesOSGRStheconnectiontothegloballocalisationcasternetworksuchasNTRIP.
ThenewarchitectureisreferredtoasOSGRSversion4.
Possiblenetworkconfigurationssuitedtodifferentscenariosarepresented.
Opensourcesoftwarearchitectureanditsmulti-GNSSassistancemodelcanprovidecoarseandfineacquisitionanddataprocessingassistancetoGNSSreceiversoperatinginweaksignalenvironmentssuchasthoseencounteredinsidebuildings.
GNSSavailabilityandaccuracycanbeimprovedwithouttheuseofproprietaryprotocolsandlicensingcosts.
KEYWORDS:OSGRSv4,LPP,NTRIP,Availability,AccuracyEnsuringtheQualityoftheAustralianNationalGNSSInfrastructureGuorongHuGeospatialandEarthMonitoringDivision,GeoscienceAustraliaTel:02-62499884;Fax:02-62499969;Email:Guorong.
Hu@ga.
gov.
auJohnDawsonGeospatialandEarthMonitoringDivision,GeoscienceAustraliaTel:02-62499028;Fax:02-62499969;Email:John.
Dawson@ga.
gov.
auBobTwilleyGeospatialandEarthMonitoringDivision,GeoscienceAustraliaTel:02-62499066;Fax:02-62499969;Email:Bob.
Twilley@ga.
gov.
auNicholasDandoGeospatialandEarthMonitoringDivision,GeoscienceAustraliaTel:02-62499552;Fax:02-62499969;Email:Nicholas.
Dando@ga.
gov.
auABSTRACTTheAustralianNationalGNSSInfrastructureconsistsoftheContinuouslyOperatingReferenceStations(CORS)oftheAustralianRegionalGNSSnetwork(ARGN),operatedbyGeoscienceAustralia(GA),andtheAuScopenetworkoperatedcollaborativelybyGAandtheStateandTerritorygeodeticagencies.
DevelopedtosupportthegeospatialsectorandEarthscienceapplications,thisnationalinfrastructureunderpinsthenationaldatum,theGeocentricDatumofAustralia(GDA),andcontributestotheGlobalGeodeticObservingSystem(GGOS)productsandservices,whichincludestheInternationalTerrestrialReferenceFrame(ITRF).
Toensurethisinfrastructuremeetstheneedsofitsusersaqualitymanagementsystemhasbeendevelopedthatincludesproceduresforsiteselection,monumentationdesign,routinedatamanagement,anddatafitness-for-purposeassessment.
ThispresentationoverviewsGeoscienceAustralia'sapproachtoqualitymanagementincludingourapproachtomonitoringtheimpactof:equipmentconfigurationchanges;antennamalfunctions;crustaldeformation;andprocessingstrategyandmodellingchanges.
SomeexamplesaregivenbasedonexperiencewithintheAsiaPacificReferenceFrame(APREF)community.
KEYWORDS:CORS,GNSS,NationalDatum,ITRF.
DevelopmentofaTestSystemforGNSSReceiverPerformanceAhmadRidhwanuddinTengkuTheUniversityofMelbourne,Australia/CRCSI(61)431452766teng@student.
unimelb.
edu.
auAssociateProfessorAllisonKealyTheUniversityofMelbourne,Australiaakealy@unimelb.
edu.
auDr.
MarkMorelandeTheUniversityofMelbourne,Australiamrmore@unimelb.
edu.
auABSTRACTTheGlobalNavigationSatelliteSystem(GNSS)industryisexperiencingrapidgrowthwithnewsignalsandconstellationsbeingactivelydeployed.
Availabilityofadditionalsignalsandsatelliteswillbenefititsuserswithbettercoverageandimprovedintegrity,butitdoesnotnecessarilyguaranteethequalityofthederivedpositioningoutput.
Assuch,itisintegraltoensurethataGNSSreceiversystemisperformingaccordingtoitsexpectedstatisticalvalues.
AproblemoftenencounteredistheinabilitytoidentifytheactualcauseofpositioningdegradationwithusershavingalmostcompletetrustontheGNSSreceiversystem.
Theproposedtestsystemattemptstodefinetheseboundariesbydeterminingtherootcauseoftheissue–whetheritisreceiverorexternallydependent.
Inconceptualisingthephysicalandfunctionalfoundationsofthetestsystem,thispaperwilladdresstheissuesfromboththeoreticalandpracticalperspectives.
Fromapracticalperspective,aGNSSsimulatorwillbeusedtoexaminetheconsistencyofGNSSreceiverstoprocesssignalsunderdifferentmodelledconditions.
TheseindividualrawmeasurementswillbethebasisofdevelopinganundifferencedstochasticmodelwhichwilleffectivelybeusedasabenchmarkforaGNSSreceiverperformance.
Auserneedsanalysiswillalsobepresented,highlightingthespecificissuesfacedbydifferentmanufacturersandendusers.
KEYWORDS:GNSSReceiverPerformance,GNSSTestSystem,GNSSSimulation,UndifferencedStochasticModelling,UserNeedsAnalysisMonitoringinEstuariesandRiverswithGNSSFloatersCharlesWang,RichardBrownandYanmingFengQueenslandUniversityofTechnology,AustraliaABSTRACTBuoysequippedwithGPSreceivershavebeenusedtomeasurewaterlevels,atmosphericparameterandotherphysicalconditionsinoceansforthepurposesofnavigation,tidecorrection,thealtimeterrangecalibrationandaspartoftsunamiwarningsystems.
Inrecentyears,somestudieshaveemergedtoapplyasimilartechnologytosmallerbodiesofwatersuchasestuariesandriversinforhydraulicmonitoringpurposes,suchasdeterminationofwaterlevelsinrivers.
ThispaperpresentsthepreliminaryresultsofnewGPSexperimentsthatmeasuretheriverflowfieldinthree-dimensionsbydeployingafree-floatingGPScapsule.
Thewaterproofcircularcylindercapsulewasdesignedanddevelopedtoallowforsimplifiedanalysisofthedragcharacteristicsandinteractswithflowinthesamemannerregardlessofdirection.
Additionally,GNSSantennawasmountedontopcompartmenttominimizeinterferencewithGNSSsignals.
ThecapsuleincorporatedadualfrequencyGNSSreceiver,miniaturecomputingandstorageplatformandbatterytolastfora12hoursmission.
Thefieldexperimentswereconductedonthe20thOctober2012.
TheGPScapsulewasdeployedinalocalestuary,EprapahCreekRiver,SouthEastofBrisbane.
Multipletestswereconductedduringdifferenttidalconditions.
ThekinematicGNSSdataobtainedfromthecapsulewascomparedwiththevelocitydatafromafixedAcousticDopplerVelocemeter(ADV)systemandtheriverheightmeasurements.
Thecapsuleperformedasexpectedduringtesting.
Thecapsulewasabletoprovidecm-levelpositioningaccuracywiththeuselocalSunPOZreferencestationwhilefreeflowingintheriver.
Theperformancesweredegradedwhenthecapsulewasmovingclosetotheriverbankduetosignalblockagesbytrees.
Finally,theheightmeasurementsfromthecapsulealignedwellwithADVsiterecordedheight.
TheGNSSmonitoringsystemdevelopedinthisresearchprovidesaflexible,lowmaintenanceandcosteffectivealternativetocurrentfixedstations.
Withtheabilitytoprovide3DLagrangianmeasurements,theadditionalinformationmaybeusefultoimprovethewatermodellingforestuariesandriversinthecaseofclimatechangesandthefloodevents.
Keywords:GNSS,real-timekinematicpositioning,free-floatingGPSbuoyandfluiddynamics.
OralPresentationsAbstracts–Thursday18July,2013Session9AQZSS0900-1020PerformanceEvaluationoftheJapaneseQuasi-ZenithSatelliteSystem(QZSS)LEXSignalinAustraliaShaochengZhangSPACEResearchCentre/RMITUniversity/Australia(03)99253709shaocheng.
zhang@rmit.
edu.
auSuelynnChoySPACEResearchCentre/RMITUniversity/Australia(03)99252650suelynn.
choy@rmit.
edu.
auKefeiZhangSPACEResearchCentre/RMITUniversity/Australia(03)99253272kefei.
zhang@rmit.
edu.
auSuqinWuSPACEResearchCentre/RMITUniversity/Australia(03)99252114suqin.
wu@rmit.
edu.
auABSTRACTTheQuasi-ZenithSatelliteSystem(QZSS)isaJapaneseregionalsatellitenavigationsystem.
Theconstellationcurrently(in2013)consistsofonehighlyinclinedgeosynchronousorbitsatelliteandthreemoresatellitesby2018.
ItaimstoaugmentthecurrentGPSserviceoverJapanandprovideJapaneseuserswithatleastoneQZSSsatellitelocatedathighelevationangle,whichgivesrisetothetermof'quasi-zenith'.
TheQZSSorbitcoveragemapshowsthattheAsiaOceaniaregionincludingAustraliaiscoveredbytheQZSSserviceandthususerswillnotonlybenefitfromhavingadditionalnavigationsatellites,butalsohavingaccesstothehighaccuracyGNSSsatelliteorbits,clocks,andregionalionospheremodeltransmittedbytheLEXsignal.
However,astheLEXserviceisoriginallydevelopedforJapaneseusers,itisnecessarytovalidatetheusabilityandfeasibilityofthisserviceinAustralia.
Inthisresearch,theGPSsatelliteorbits,clocksandionospheremodeltransmittedfromtheLEXsignalarecomparedwiththeIGSpreciseproducts.
DatacollectedatseveralAustralianCORSstationsarethenpost-processedusingPrecisePointPositioning(PPP)tovalidatethequalityoftheestimatedpointpositions.
TheresultsshowthattheGPSsatelliteorbitsandclockstransmittedbytheLEXsignalhaveanaccuracyoflessthan1metreand2nanoseconds,respectively.
Thepositioningresultsfromthedual-frequency(ionosphere-free)PPPprocessingareaccuratetosub-metrelevel;andthesinglefrequencyuserscannotbenefittheionosphericcorrectionparametresasthemodelisgeneratedforJapaneseregional.
ItcanbeconcludedthatthecurrentQZSSLEXorbitsandclocksservicecanprovidesub-metrepointpositioningserviceinAustralia,howevertheionospherecorrectionparametresfromLEXservicecannotbeusedinAustralianarea,thefutureAustraliaionosphericgridwillbeanecessarysupplementforQZSSLEXservice.
KEYWORDS:GNSS,QZSS,SatelliteOrbitsandClocks,IonosphericDelay,PrecisePointPositioning.
KinematicEstimationofQZSSOrbitswithTripleFrequencyMeasurementsYongchaoWang(1)CooperativeResearchCentreforSpatialInformation,QueenslandUniversityofTechnology,AustraliaCharlesWang(2)CooperativeResearchCentreforSpatialInformation,QueenslandUniversityofTechnology,AustraliaYanmingFeng(3)SchoolofElectricalEngineeringandComputerScience,QueenslandUniversityofTechnology,AustraliaABSTRACTTheexistingGNSSorbitalsolutions,regardlessofbroadcastorbitalandpreciseorbitsolutions,arederivedfromdual-frequencycodeandphasemeasurementscollectedoverdataarcsof24-48hours.
However,someoperationalsatellitesofdifferentGNSSconstellations,suchasGPSIIF,QZSSMICHIBIKIandseveralrecentCompasssatelliteshavebeenabletotransmitcodeandphaserangingsignalsatthreeormorefrequencies.
Astraightforwardquestionishowthreetripleormulti-frequencysignalscancontributetoGNSSorbitssolutions.
ThispaperpresentskinematicorbitestimationalgorithmsusingQZSStriplefrequencyphaseandcodemeasurementsoverseveralminutescollectedfromaboutgroundGPS/QZSSstationsintheAsia-Oceaniaregion.
Thekeyistoestimationofionosphere-freenarrow-lanephasebiasestotheaccuracyofabout10centimetreseveryfewminutes,whichcanbeusedtoreplacetheionosphere-freecodemeasurementsusuallyusedintheorbitestimation.
AnotherimportantstrategyisuseofGPSmeasurementsandpreciseorbits/clockstoestimatethereceiverclocksandzenithdelays.
Withknowngroundclocks,preciseundifferencedionosphere-freerangemeasurements,theQZSSstatesarebedeterminedeveryepochandimprovedoverminutes.
QZSSorbitestimationexperimentalresultsfrom20stationsequippedwithTrimbleR9receiverswillbeanalysedandcomparedwithQZSSbroadcastorbitsandJAXApreciseorbitsolutions.
ItpreliminarilydemonstratesthatthekinematicQZSSorbitalsolutionscanachievesub-metreorbitalaccuracy,whichisexpectedtobefurtherimprovedthroughtheusualorbitimprovementprocedurestotheaccuracyofbetterthan10centimetresinthefuture.
KEYWORDS:QZSS,PreciseOrbitDetermination,Triplefrequency,kinematicorbitestimation.
QZSSLEXReceiverDesignBinLeiSchoolofElectricalEngineeringandTelecommunicationsTheUniversityofNewSouthWalesSydneyNSW2052,AustraliaJinghuiWuAustralianCentreforSpaceEngineeringResearchattheUniversityofNewSouthWales/Australia+61293854206/jinghui.
wu@unsw.
edu.
auAndrewG.
DempsterAustralianCentreforSpaceEngineeringResearchattheUniversityofNewSouthWales/Australia+61293856890/a.
dempster@unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineeringattheUniversityofNewSouthWales/Australia+61293854205/c.
rizos@unsw.
edu.
auABSTRACTSincethefirstGPSsatellitewaslaunchedinthe1970s,severalsatellite-basednavigationsystemshavebeendeployedgloballyorregionally.
Inthemeantime,researchersarestilltryingtodevelopinnovativesystemswhichcanprovidehigh-accuracypositioning,navigation,time(PNT).
Toenhancepositioningperformance,theJapaneseaugmentationsatellitesystemQZSS(QuasiZenithSatelliteSystem)broadcastsauniqueLEXOpenServicesignalfromtheQZSSsatellite"MICHIBIKI"tosupportprecisepointpositioning(PPP)ordifferentialGNSS.
ItiscompatibleandinteroperablewiththeEuropeanUnion'sGalileosignals.
AustralianresearchersanduserscantakeadvantageoftheQZSStoenhancePNTresults.
Inthisproject,theL-bandLEXsignalistheresearchfocususingasoftwareapproachbasedonMatlabsimulationofthetrackingreceiver.
TheaimwastomodifyexistingsoftwareusedforGPSL1C/AprocessingsothatitwouldbesuitableforLEXsignalprocessing.
DesignchallengessuchasCSKddemodulationandde-multiplexingoftheShortandLongCodeweretackledsothatnewacquisitionandtrackingapproachescouldbeproposedfortheLEXsignal.
KEYWORDS:GPS,GNSS,QZSS,Galileo,LEXReal-timePrecisePointPositioningUtilisingtheJapaneseQuasi-ZenithSatelliteSystem(QZSS)LEXCorrectionsSuelynnChoySchoolofMathematicalandGeospatialSciences,RMITUniversity,AustraliaPhone:+61399252650Fax:+61396632517Email:suelynn.
choy@rmit.
edu.
auKenHarimaSchoolofMathematicalandGeospatialSciences,RMITUniversity,AustraliaPhone:+61399253775Fax:+61396632517Email:ken.
harima@rmit.
edu.
auYongLiSchoolofSurveying&GeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854173Fax:+61293137493Email:yong.
li@unsw.
edu.
auYakaWakabayashiSatelliteApplicationandPromotionCentre,SpaceApplicationsMissionDirectorate,JapanAerospaceExplorationAgency,JapanPhone:+81-50-3362-3558Fax:+81-29-868-5987Email:wakabayashi.
yaka@jaxa.
jpHiroakiTateshitaSatelliteApplicationandPromotionCentre,SpaceApplicationsMissionDirectorate,JapanAerospaceExplorationAgency,JapanPhone:+81-50-3362-3361Fax:+81-29-868-5987Email:tateshita.
hiroaki@jaxa.
jpSatoshiKogureSatelliteApplicationandPromotionCentre,SpaceApplicationsMissionDirectorate,JapanAerospaceExplorationAgency,JapanPhone:+81-50-3362-2456Fax:+81-29-868-5987Email:kogure.
satoshi@jaxa.
jpChrisRizosSchoolofSurveying&GeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854205Fax:+61293137493Email:c.
rizos@unsw.
edu.
auABSTRACTTheQuasi-ZenithSatelliteSystem(QZSS)isaJapaneseregionalsatellitenavigationsystem(whenfullydeployed)consistingofseveralQZSSsatellitesinhighlyinclinedellipticalorbits.
Thismeansthatatleastonesatelliteisconstantlylocatedatahighangleofelevation,whichgivesrisetotheterm'quasi-zenith'.
QZSSisasatellite-basedaugmentationsystemforGPSandGalileo,capableoftransmittingnavigationsignalsthatarecompatibleandinteroperablewithbothoftheseGlobalNavigationSatelliteSystems(GNSS).
Inadditiontothenavigationsignals,QZSSalsotransmitsaugmentationsignals,e.
g.
theL-bandExperimental(LEX)signalontheE6bfrequency.
TheLEXsignalisuniqueforQZSSdeliverscorrectionmessages–suchasorbitsandclockinformation–thatenablePrecisePointPositioning(PPP)forreal-timeapplications.
TheaimofthisresearchistoevaluatetheQZSSLEXsignalandthequalityofthebroadcastcorrectionmessagesontheLEXforreal-timePPP.
ThesystemwillbetestedinbothstaticandkinematicpositioningmodeinMelbourneinearlyMarch2013;andtheresultswillbepresentedandcomparedtopositioningsolutionsderivedfromconventionalpositioningtechniques,e.
g.
Real-TimeKinematic(RTK).
ThiswillbethefirstattemptinAustraliaatevaluatingthefeasibilityofusingtheQZSSLEXsignaltodeliverahighaccuracyreal-timepositioningservicetoAustralianGNSSusers.
ThisisacollaborativeresearchprojectbetweentheCooperativeResearchCentreforSpatialInformation(CRCSI)andtheJapanAerospaceExplorationAgency(JAXA).
KEYWORDS:GPS,QZSS,LEX,PPP,GNSS.
Session9BOrbitDetermination0900-1020ImpactofOrbitDynamicsonGPS-BasedSatelliteOrbitDeterminationLiQiaoAustralianCentreforSpaceEngineeringResearch,SchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,Australia61(2)93856705&61(2)93137493l.
qiao@unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,Australia61(2)93854205&61(2)93137493c.
rizos@unsw.
edu.
auAndrewDempsterAustralianCentreforSpaceEngineeringResearch,SchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,Australia61(2)93856890&61(2)93137493a.
dempster@unsw.
edu.
auABSTRACTDuetothesuccessofGPSspaceapplicationsmoreandmorespacemissionsarenowreplyingonGPStechnology.
AcommonlyusedapproachtoGPS-basedsatelliteorbitdeterminationistousefilteringalgorithmssuchasabatchestimatororKalmanfiltertoblendon-boardorbitalGPSobservationswithorbitdynamics.
InsomesituationswhenthegeometryofGPSsatellitesispoor,theorbitdynamicsalgorithmcanpredicttheorbittrajectorywiththerequiredlevelofaccuracy.
Consideringtheon-boardcomputationalworkload,theorbitdynamicsalgorithmcouldaccountforalltheperturbations.
Buttowhatextenttheorbitdynamicsmodelcanbereducedwithoutintroducingtoomucherrorinorbitdetermination/predictionisworthyofstudy.
ThispaperreviewstheorbitdynamicsmodelsforvarioussatellitemissionsfromLowEarthOrbittoHighEarthOrbit.
Thenthepaperdiscussestheimpactofgravitationalandnon-gravitationalforces,andtheintegrationmethodontheorbitdetermination/predictionperformance.
AnassessmenttoolhasbeendevelopedusingSTKandMatlabtoassistinevaluatingorbitdynamicsperformanceunderdifferentmissionscenarios.
KEYWORDS:orbitdynamics,on-boardGPS,orbitdeterminationAnalysisofRegionallyEnhancedGPSOrbitandClockSolutionsforSupportingReal-TimePositioningCharlesWangandYanmingFengQueenslandUniversityofTechnology,Australia,cc.
wang@qut.
edu.
auShengfengGuandChuangShiWuhanUniversity,ChinaABSTRACTCurrently,severalIGSAnalysisCentres,suchasGFZandCODE,aregeneratingultra-rapidGPSorbitandclocksolutionsfromapproximately80~120globalCORSinsupportingreal-timeapplication.
Suchsolutionsaretypicallyaccuratetoapproximately3cmand150psforobservedorbitandclocksolutionandapproximately5cmand3nsforpredictedorbitandclocksolution.
Although,thepredictedorbitsareofhighquality,largeerrorofmorethan10cmcansometimesoccurandcanimpactonthequalityofpositioning(PPPinparticular),downgradingaccuracyandincreasinginitialisationtimes.
ThisworkexploresthebenefitsofusingaregionallyenhancedCORSnetworktoderiveGPSorbitandclocksolutionsforsupportingreal-timeapplication.
TheregionallyenhancednetworkiscomprisedofaglobalevenlydistributedCORSnetworkwithadditionofadenselydistributednetworkinAustraliaandNewZealandregion.
AseriesofcomputationalschemeswereperformedtodemonstratethebenefitsofsuchnetworkontheGPSorbitandclocksolutions.
GamitandPANDAsoftwarewereusedtocomputedailyGPSorbitsolutionsfromdifferentnetworkconfigurationsofglobalnetworks(G35,G65,G84andG100)andregionalnetwork(A20,A50,A80).
ThesolutionperformanceswereanalysedbasedontheorbitaldifferenceswithrespecttotheIGSfinalorbitsolution.
Theresultshowsoverallimprovements(upto14%)intheregionallyenhancedorbitsolutions,forbothGamitandPandaPODprocessing,comparedtothesolutionsderivedfromglobalnetwork.
WhencomparingtoSIUhourlyultra-rapidsolutions,QUTGamitderivedregionallyenhancedorbitcanprovideimprovementsof15~28%intheestimatedorbitsolutionand12~26%inthepredicted(24hr)solution.
Additionally,theorbitaldifferencesoverGPSsatellitearcsthatarevisiblebyanyofthefivechosenAustralianCORSstations(ALIC,DARW,TOW2,HOB2andYAR3)showshigherpercentageofimprovementscomparedtosatellitearcsnotvisiblewithinAustralianregion.
Finally,itisnotedthattheuseofmoreregionalstations(>20)doesnotnecessarilyofferadditionalbenefits,itismoreimportanttokeepuseofwelldistributedandhighqualitystations.
Therecommendedconfigurationforgeneratingregionallyenhancedorbitsolutionsisawelldistributed100to120stationsofwhichatotalof20to30stationschosenfromAustralianandNewZealandregion.
TheregionallyenhancedclocksolutionswerecomputedwithPANDAsoftwareusingacombinationofG65,G100andA50networkconfigurationsfor30daysduration.
AnalysishaveshownimprovementsintheregionallyenhancedclocksolutionswhereRMSforG65,G65+A50,G100andG100+50networkconfigurationsare0.
113ns,0.
090ns,0.
073nsand0.
070nsrespectively.
KEYWORDS:GPS,regionalenhancement,preciseorbitdeterminationandclockestimation.
EstimationofInitialStateandModelParametersforAutonomousGNSSOrbitPredictionJuhaAla-LuhtalaTampereUniversityofTechnology/FinlandPhone:+358456509464,juha.
ala-luhtala@tut.
fiMariSeppnenTampereUniversityofTechnology/Finlandmari.
j.
seppanen@tut.
fiHenriNurminenTampereUniversityofTechnology/Finlandhenri.
nurminen@tut.
fiSimoAli-LyttyTampereUniversityofTechnology/Finlandsimo.
ali-loytty@tut.
fiRobertPichéTampereUniversityofTechnology/Finlandrobert.
piche@tut.
fiABSTRACTInself-assistedGNSStheorbitofasatelliteispredictedbysolvingthedifferentialequationthatmodelsitsmotion.
Theequationofmotionconsistsofaccelerationsduetodifferentforces.
Ourmodelincludesthemostimportantoftheseforces:Earth'sgravity,LunarandSolargravityandSolarradiationpressure.
TheeffectofunmodeledforcesistakenintoaccountbyusingGaussianwhitenoisewithcovariancematrixestimatedfromhistoricalorbitaldata.
Theestimationofmodelparameters(SolarradiationpressureandEarthOrientationparameters)andinitialstateforthepredictionisconductedintwosteps.
First,theparametersthatareexpectedtostayunchangedforlongperiodsoftimeareestimatedusingthepreciseorbitsgeneratedbytheInternationalGNSSService(IGS).
Inthesecondstep,thesatellite'sbroadcastephemerisisusedtoestimatetheinitialstateanddynamicmodelparameters.
Theestimationstepsareformulatedasnon-linearcontinuous-discretetimefilteringproblems.
Thefilteringequationsareintegratednumericallyandtheperformanceofdifferentnumericalintegrationmethods(Extended,CubatureandUnscentedKalmanfilters)iscompared.
Usingtheestimatedinitialstateandmodelparametersthesatellitesorbitispredicted5daysintothefuture.
TheaccuracyandconsistencyofthepredictedorbitsisanalysedusingtheIGSpreciseephemerides.
InthispaperonlyGPSsatellitesareconsidered,butthemethodcanbeextendedtoothersatellitesystems.
KEYWORDS:Satelliteorbitprediction;Gaussianfiltering;EstimationSession9CGSNSSInfrastructureII0900-1020DesigningandImplementingaSuccessfulGNSSInfrastructureProjectNeilAshcroft,LeicaGeosystems,SingaporeJolVANCRANENBROECK,LeicaGeosystems,SwitzerlandVincentLUI,LeicaGeosystems,HongKongABSTRACTMostoftheGNSSNetworkRTKprojectshavebeendevelopedbytheeconomicaljustificationthatanactivegeodeticnetworkwouldreducethecostofmaintainingatraditional(passive)geodeticnetworkwherethemaintenanceofthebenchmarksandthecontrolsurveywereasignificantpartoftheowner'sbudget.
AGNSSNetworkRTKcanalsobejustifiedwheretherewasnogeodeticnetworktoassistthecreationandthemaintenanceofaSpatialDataInfrastructuretosupportlandgovernanceandcadastreoperations.
Wealsohaveseenthedecisiontodeploysuchtechnologyaspartofprestigefromgovernmentalorganizationsbutwithoutaclearanalysisofuser'sneedandbusinessplanleavingsuchpositioninginfrastructurewithonlyfewusersandarequesttore-engineertheapproach.
Theauthorshavebeeninchargeofboththedevelopmentofthetechnologyandalsoonthepromotion,thedesignandtheimplementationofnumerousGNSSNetworkRTKpositioninginfrastructuresworldwide.
Thispaperisdealingwiththereasonstheauthorshaveidentifiedtomakesuchprojectasuccessorafailure.
KEYWORDS::GNSSInfrastructure,GPS,GLONASS,COMPASS,GALILEO,GNSS,RTCM,RTK,NTRIP,BusinessModelInvestigationofVirtualRINEXDataPerformanceVolkerJanssenSurveyInfrastructureandGeodesy,LandandPropertyInformationNSWDepartmentofFinance&Services,BathurstNSW2795,AustraliaTel:+61-2-63328426,Fax:+61-2-63328479,Email:Volker.
Janssen@lpi.
nsw.
gov.
auABSTRACTNetworkRealTimeKinematic(NRTK)GlobalNavigationSatelliteSystem(GNSS)technologyisincreasinglybeingutilisedforawiderangeofpositioningapplications.
TheadvantageofNRTKisitsabilitytoprovidecorrections(accountingforatmosphericandsatelliteorbiterrors)thatarebasedonaContinuouslyOperatingReferenceStation(CORS)networkratherthanasinglereferencestation.
WhilemostusersemployNRTKforreal-timeapplications,itisalsopossibletobenefitfromnetwork-basedGNSScorrectionsforpost-processingapplications.
ThisisachievedthroughtheprovisionofVirtualRINEXdata,i.
e.
datathatwouldhavebeenobservedataninvisible,unoccupied(i.
e.
virtual)GNSSreferencestationspecifiedbytheuser.
ThispaperinvestigatestheperformanceofVirtualRINEXdatacomparedtoobserveddata.
Anextensive3-daydatasetisusedtocomparestaticpositioningresultsobtainedwithVirtualRINEXdatageneratedbyCORSnet-NSWandRINEXdataobservedatthreetestsites(incorporatingsmallandlargeNRTKcells)inNewSouthWales,Australia.
Ateachtestsite,dataareanalysedinthreeways:(1)'zero'baselineprocessingbetweenvirtualandobserveddataforsessionlengthsrangingfrom24hoursto10minutes,(2)AUSPOSprocessingusingvirtualandobserveddatafor24-hour,6-hourand2-hoursessions,and(3)baselineprocessingrelativetofoursurroundingCORSusingvirtualandobserveddataforsessionlengthsof24hours,1hourand10minutes.
Itisfoundthat'zero'baselinesvaryfrom1mm(hz)and2mm(vt)forlongobservationsessionsinasmallNRTKcellto15mm(hz)and40mm(vt)forallobservationwindowsinvestigatedinalargeNRTKcell.
24-hourAUSPOSsolutionsbasedonVirtualRINEXdataagreewiththoseusingobserveddataatthe10mmlevelorbetter,while2-hoursolutionsshowdifferencesofuptoabout20mm(hz)and40mm(vt).
BaselineprocessingtosurroundingCORSrevealsdifferencesrangingfromthefew-mmlevelforshort(10km)baselinesinasmallNRTKcelltothefew-cmlevelforlong(60km)baselinesinalargeNRTKcell.
TheseresultsindicatethatVirtualRINEXdatacanbecomparabletoobserveddataforsomeapplications,providedNRTKcellsize,observationlengthandbaselinelengtharetakenintoconsideration.
KEYWORDS:GNSS,VirtualRINEX,NetworkRTK,CORSnet-NSW.
Victoria'sGNSSCORSinfrastructure–CurrentStatusandApplicationtoReferenceFrameMaintenanceandResearchDrRogerFraserDepartmentofEnvironmentandPrimaryIndustries,Victoria,Australia+61386362551,roger.
fraser@dse.
vic.
gov.
auHaydenAsmussenDepartmentofEnvironmentandPrimaryIndustries,Victoria,Australia+61386362374,hayden.
asmussen@dse.
vic.
gov.
auABSTRACTTheDepartmentofEnvironmentandPrimaryIndustries(DEPI)inVictoriacontinuestomaintainastatewideGlobalNavigationSatelliteSystem(GNSS)ContinuallyOperatingReferenceStation(CORS)networkknownasGPSnet.
Sinceitsinitialestablishmentin1996,GPSnethasbeenusedinawidearrayofapplicationsincludingengineeringandcadastralsurveying,mining,railandportoperations,precisionagriculture,vegetationmapping,environmentalscienceandassetmanagement.
Inresponsetofactorssuchasconsumerexpectationandtechnologicalevolution,GPSnethasseenconsiderableexpansionandenhancementoverthelastdecade.
ThispresentationprovidesanoverviewofthecurrentstatusofGPSnet,includingasummaryofvariousissuesrelatingtotheoperationofastatewideCORSnetwork.
ThispresentationalsosummarisestheapplicationofGPSnettoAustralianandregionalreferenceframemaintenance,anditscontributiontoGNSSrelatedresearchactivitiesintheAustraliancontext.
KEYWORDS:NetworkReal-TimeKinematic,GNSS,CORS,referenceframe,research.
EstimatingCoordinateUncertaintyinAUSPOSMinghaiJiaGeoscienceAustraliaPhone:+61262499045Fax:+61262499999Email:minghai.
jia@ga.
gov.
auJohnDawsonGeoscienceAustraliaPhone:+61262499028Fax:+61262499999Email:john.
dawson@ga.
gov.
auABSTRACTAUSPOSisGeoscienceAustralia'son-linestaticGPSpositioningservice,providinguseraccesstoastate-of-artanalysissystemviaasimpleweb-interface.
AUSPOSdeliversITRF2008,GDA94andAHDcoordinatestoAustralianusersandITRF2008coordinatestointernationalusersbysimultaneouslyprocessingupto7daysofuser-suppliedGPSdatafromupto20sites.
LikeotherGPSdataprocessingsystems,theinternalcoordinateuncertaintyofAUSPOSsolutionsistypicallyoptimistic.
Inthispaper,wereportonamorerealisticuncertaintyestimationmethodforAUSPOS.
TestresultsusingthismethodshowthatuncertaintiesofAUSPOSsolutionsvaryfromseveralmillimetrestoseveralcentimetres,withrespecttoITRF2008,dependingonthedurationofdatasetsandtheirgloballocation.
KEYWORDS:AUSPOS;GPS;UncertaintySession10APrecisePointPositioningandGNSSMeteorology1050-1230Real-TimePrecisePointPositioning–AreWeThereYetThomasGrinterUniversityofNewSouthWales,Sydney,AustraliaPhone:(02)63328211Email:Thomas.
Grinter@lpi.
nsw.
gov.
auABSTRACTTheconceptofPrecisePointPositioning(PPP)usingGlobalNavigationSatelliteSystem(GNSS)technologywasfirstintroducedin1976,howeverittookuntilthe1990sforPPPtogenerateinterestamongstthegreaterGNSScommunity.
Overthelasttwodecades,dual-frequencyPPPhasbeenextensivelyresearched,culminatingintheavailabilityofPPPpost-processedcorrectionproductsfromorganisationssuchastheNationalAeronauticsandSpaceAdministration(NASA)JetPropulsionLaboratory(JPL),theInternationalGNSSService(IGS)andNaturalResourcesCanada(NRCan).
Withtheadventofcost-effective,accurate,Real-TimeKinematic(RTK)positioningprovidedbyanincreasingnumberofContinuouslyOperatingReferenceStation(CORS)networksaroundtheworld,thefocusofPPPhasshiftedtoreal-timeornearreal-timesolutions.
Areal-timeornearreal-timePPPsolutionwouldpotentiallyallowforaviablealternativetoRTKsolutionsinsomecircumstances,whilemaintainingtheadvantagesofPPPoverdifferentialreal-timeproducts.
However,severallimitationsstillremain,primarilythelongconvergencetimesneededtoresolveambiguities,currentlyrestrictingtheuseofPPPforreal-timeapplications.
ThispaperprovidesabriefhistoryofthedevelopmentofPPPandreviewstheadvancesmadeinPPPinthelasttwodecadeswithanemphasisonthedevelopmentofareal-timeornearreal-timePPPsolution.
KEYWORDS:PrecisePointPositioning,GNSS,CORS,Real-TimeKinematic,IGS.
AReferenceStation-basedGNSSComputingModetoSupportUnifiedPrecisePointPositioningandRealTimeKinematicPositioningServicesYanmingFengandCharlesWangQueenslandUniversityofTechnology,Australia,y.
feng@qut.
edu.
auShengfengGuandChuangShiWuhanUniversity,ChinaChrisRizosTheUniversityofNewSouthWales,AustraliaABSTRACTCurrently,theGNSScomputingmodesareoftwoclasses:userreceiver-basedprocessingandnetwork-baseddataanalysis.
AGNSSreferencereceiverstationessentiallycontributesrawmeasurementdataineithertheRINEXfileformatorasreal-timedatastreamsinanRTCMformat.
Verylittlecomputationaleffortisdonebythereferencestation.
ThispaperdescribesanewGNSScomputingframeworkthatincorporatesthreeGNSSmodes:referencestation-based,userreceiver-basedandnetwork-baseddataprocessing.
ItisproposedthatrawdatastreamsfromeachGNSSreferencereceiverstationbeprocessedinadistributedmanner,i.
e,ateitherthestationitselforatahostingdataserver/processor,togeneratestation-basedsolutions(andperhapsadditionalusefulinformation).
Thestation-basedprocessingreferredtohereissimilartothe"precisepointpositioning"(PPP)technique.
PPPprocessingestimatesanumberof"local"parametersbutkeepsthesatelliteorbits/clocksandthereferencereceiverstationcoordinatesfixed.
Theestimatedreferencereceiver-specificparametersincludeprecisereceiverclock,zenithtroposphericdelay,anddifferentialcodebiases,aswellasline-of-sightinformationsuchasionosphericdelays,L1andL2ambiguityparameters,azimuthandelevationangles.
Insuchamodenotonlycanthenearbypositioningusersdirectlyapplysomeofthecorrectionsfromthereferencestation(s)forenhancedreal-timeprecisepositioning,butalsovariousnetwork-baseduserscanformlinearobservationequationsystemsdirectlyfromeachreferencestationsolutiontosupportcommercialservicesandscientificdataanalysis.
Attheuserreceiver,PPPandreal-timekinematic(RTK)modesareunifiedunderthesameobservationmodels,andthedistinctionishowtheuserreceiversoftwaredealswithcorrectionsfromthereferencestationsolutionsandtheambiguityestimatesintheobservationequations.
Preliminarynumericaltestsdemonstratethatthereferencestation-basedsolutions,suchastheconvergenceofambiguityestimates,canstabilisewithin4hoursofreceiveroperation.
Withstation-basedsolutionsfromthreereferencestationswithindistancesof20to100kmtheuserreceiverpositioningresultswithvariousschemeswereanalysed,showingaccuracyimprovementoftheproposedstation-augmentedPPPsolutionswithrespecttothetraditionalPPPsolutions.
KEYWORDS:GNSS,station-basedprocessing,precisepointpositioning,network-basedanalysis,andreal-timekinematicpositioning.
ComparingGPSRadioOccultationObservationswithRadiosondeMeasurementsOverAntarcticaR.
Norman1,J.
LeMarshall1,2,B.
A.
Carter1,K.
Zhang1,G.
Kirchengast3,S.
Alexander4,C-S.
Wang1andY.
Li11SatellitePositioningforAtmosphere,ClimateandEnvironment(SPACE)ResearchCentre,RMITUniversity,Melbourne,Australia,Tel:99256735,email:robert.
norman@rmit.
edu.
au2CentreforAustralianWeatherandClimateResearch(CAWCR),BureauofMeteorology,Melbourne,Australia3WegenerCenterforClimateandGlobalChange(WEGC),UniversityofGraz,Graz,Austria4AustralianAntarcticDivision,Hobart,Tasmania,AustraliaABSTRACTGPSRadioOccultation(RO)isaspace-basedtechniqueforsoundingtheEarth'satmosphere.
ThistechniquehasbeenshowntosignificantlyimproveweatherforecastingandclimatemonitoringovermanyregionsoftheEarth.
TheGPSROtechniqueusesspecially-designedGPSL-bandfrequencyreceiverson-boardLowEarthOrbit(LEO)satellitestoreceivesignalsfromGPSsatellites.
TheConstellationObservingSystemforMeteorology,IonosphereandClimate(COSMIC)isajointTaiwanandUSAsatelliteprogramandwaslaunchedintoorbitinApril2006.
GPSROdatafromthisconstellationofsixFORMOSAT-3(FormosaSatelliteMission#3),LEO(800kmaltitude)micro-satellitesprovidesanobservationaldatatypeforoperationalmeteorologyandsignificantinformationonthethermodynamicstateoftheatmosphere.
IntheAntarcticregionthereareonly18radiosonde(RS)weatherstationsmainlydistributedalongthecoastalfringe.
AssuchthisRSnetworkisfarfromidealforstudyingtheatmosphere,meteorologyandclimatologyintheAntarcticregion.
ItdoeshoweverprovideexcellentreferencestationstotestandvalidatetheGPSROtechniqueasasuitablemeteorologicaldatatypeintheAntarcticregion.
InthisstudytheCOSMICGPSROtemperatureandpressureprofilesarecomparedtothosemeasuredusingradiosondesintheAntarcticregion.
Yearlyandseasonally,weightedareaaveragetemperatureprofilesfromtheAntarcticregionarealsopresented.
KEYWORDS:RadioOccultation,Antarctica,radiosonde,satellites,COSMICANewAustralianGNSSRadioOccultationDataProcessingPlatformKefeiZhangSPACEResearchCentre/RMITUniversity/Australia(03)99253272kefei.
zhang@rmit.
edu.
auShaochengZhangSPACEResearchCentre/RMITUniversity/Australia(03)99253709shaocheng.
zhang@rmit.
edu.
auJohnLeMarshallTheAustralianBureauofMeteorologyRobertNoman,YingLi,CongliangLiuandBrettCarterSPACEResearchCentre/RMITUniversity/AustraliaABSTRACTGNSSRadioOccultation(RO)isarobustspace-bornetechnologyforsoundingtheEarth'satmospherewithglobalcoverage.
ThedataretrievedusingGNSSROhasbeendemonstratedwithunprecedentedadvantagesandusedtoimproveoperationalweatheranalysisandforecastingandtoassistinregionalreanalysisandclimatemonitoring.
Thistechnologyhasbeenconsideredasanewavenueforprofilingtheatmospherewithahighaccuracyandhighverticalresolutionthatisnotsubjecttobiasesandinstrumentdriftingandhasheraldedaneweraofclimate,weatherandsevereweatherforecastingsystems.
Mostrecently,GNSSROprofilesfromCOSMIC,MetOpandGRACEhavebeensuccessfullyusedoperationallyinAustraliaandeight-hourimprovementhasbeendemonstrated.
In2010,aprestigiousAustraliaSpaceResearchProgram(ASRP)projectwasawardedtoaninternationalconsortiumledbytheSPACEResearchCentreinRMITUniversity.
Theaimsofthismulti-milliondollarASRPprojectaretodevelopplatformtechnologiesforSpace,AtmosphereandClimate.
AnumberofsoftwareplatformsintheareasofGPSradiooccultation,spacetrackingandatmospheremodellinghavebeendevelopedsincebeingawardedtheASRPproject.
ThiscontributionintroducesthenewGNSSdataprocessingplatformdevelopedincludingitsrationale,mainfunctionalities,processingengineandalgorithmusedetc.
ThesystemisdevelopedbasedonacustomizedBerneseGPSsoftwareplatformwithselectedprocessorsfrombothEGOPSandROPP.
ThecurrentversionofthesystemisabletocarryoutextensivedataprocessingfromLevel0LEOon-boardreceiverrawobservationstotheLevel2atmosphericprofilesofbendingangle,refractivity,temperatureandpressure.
ThisnewGNSSROplatformconsistsofseveralmajormodules,i.
e.
LEOsatellitepreciseorbitdeterminationmodule,GNSSROexcessphasedataprocessingmodule,qualitycontrolmoduleandatmosphereparameterretrievalmodule.
VariousresultsfromthisnewsystemhavebeencomparedwithotherindependentROdataprocessingproducts(e.
g.
UCAR)andconsistentresultshavebeenobtained.
ItisanticipatedthatthenewGNSSROsystemwillprovideanimportantresearchplatformforourresearchandavaluablecontributiontotheinternationalcommunityinGNSSRO.
ThissystemcanbeaveryusefultoolfortheoperationalusageoftheGNSSROinAustralianNWPmodels,severeweatherandclimateresearch.
ThiswillalsobeanimportantstepforwardforfutureAustralianGNSSsatelliteremotesensingprograms.
KEYWORDS:GNSSradiooccultation,PlatformTechnology,Bernese,Atmosphere.
ImprovedRealTimeIonosphericScintillationandTECMonitoringUsingAllGNSSConstellationsRodMacLeodNovAtelAustraliaPtyLtdSydney,NSW,AustraliaABSTRACTGiventhepredictableimpactoftheIonosphereontheGNSSsignals,thesesignalsprovideanexcellenttoolforionosphericmonitoringonaglobalandcontinuousbasis.
ThepresentationdiscusseshowIonosphericdisturbancesinducerapidfluctuationsinthephaseandtheamplitudeofreceivedGNSSsignalsandtheshortcomingsofpreviousionosphericmonitoringthatusedGPSonlySemi-codelessL2trackingdualfrequencyreceivers.
Thesereceiversgreatlylimitedtheaccuracy,robustnessandutilityoftheTECmeasurementsandwereuselessforscintillationmeasurementsonL2.
ItprovidesrealtimeresultsofNovAtel'sGPStation-6receiverwiththeabilitytonowtrackmulti-frequencymeasurements,forallGPS+GLONASS+GALILEO+BEIDOU+QZSSsatellitesbyusinganewspecializedreceiverdesignthatprovidesrobustandlessnoisyrealtimeionosphericmeasurements.
KEYWORDS:ionosphere;GNSS;amplitudescintillation;phasescintillation;totalelectroncontent(TEC);spaceweather;monitoring.
Session10BNetworkandSignalProcessing1050-1230MixedSignalsDOAEstimationMethodinthePresenceofNonuniformNoiseYuexianWangSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiajwang@eleceng.
adelaide.
edu.
auMatthewTrinkleSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiamtrinkle@eleceng.
adelaide.
edu.
auBrianNgSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiabrian.
ng@adelaide.
edu.
auABSTRACTAnewestimationmethodcombiningobliqueprojectorandspace-timematrixalgorithmisproposedwhenuncorrelatedandcoherentsourcescoexist.
Withthisalgorithm,thecoherentandincoherentsourcesareestimatedseparately.
Thecoherentsourcesareestimatedbyexploringthesymmetryofarraygeometrytoavoidthesignificantlossofarrayapertureandhighcomputationoftheconventionalsmoothingmethod.
TheobliqueprojectorinsteadofdifferencingmethodisusedtomakethealgorithmworkwithouttherestrictionofToeplitzconfiguration.
Therefore,thealgorithmissuitableforarbitraryarraystructure.
Thismethodcanobviouslyimprovetheoverloadcapabilitytoresolvesources,andalongwiththeprocessingoftime-spacematrixreconstruction,thenonuniformnoiseistransformedtowhitenoise.
Asaresult,themethoddiscussedcanfullyeliminatenonuniformnoise.
KEYWORDS:centre-symmetricvirtualarray;directionofarrival(DOA);coherentsignals;nonuniformnoiseDesignofNetworkArchitectureforRoutinginTerrestrialandSatelliteNetworkKwang-ChunGoSchoolofElectricalandComputerEngineering,AjouUniversity,Korea+82-31-219-2474,xaviersr@ajou.
ac.
krJae-HyunKimSchoolofElectricalandComputerEngineering,AjouUniversity,KoreaABSTRACTInaterrestrialnetworkinterworkingwithsatellitenetworks,itisimportanttodesigntheoptimalnetworkarchitectureforselectionofefficientroutingpaths.
Especially,thesatellitenetworkhasdifferentcharacteristicscomparedwiththeterrestrialnetwork.
Thus,thecharacteristicsofsatellitenetworksshouldbeconsideredtodesigninterworkingnetworkarchitecture.
Inthispaper,wedesignnetworkarchitecturebyconsideringthecharacteristicsoftheterrestrialnetworkinterworkingwiththesatellitenetworks.
WeintroduceseveraldesigncriteriasuchasASseparation,NCCconfiguration,topologyofsatellitelink,andetc.
Then,weconsiderallcombinationsofthecriteriatodesigntheroutingscenariosonthenetworkarchitecturesandevaluatetheadvantagesanddisadvantagesbetweenroutingscenarios.
Finally,weproposeefficientnetworkarchitectureoftheterrestrialnetworkinterworkingwithasatellitenetworkandevaluatetheend-to-enddelayandpacketerrorrateperformancefortheproposednetworkarchitecture.
KEYWORDS:Routing,Networkarchitecture,Terrestrialnetwork,SatellitenetworkDOAEstimationforUncorrelatedandCoherentSignalswithCentre-symmetricVirtualArrayYuexianWangSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiajwang@eleceng.
adelaide.
edu.
auMatthewTrinkleSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiamtrinkle@eleceng.
adelaide.
edu.
auBrianNgSchoolofElectricalandElectronicEngineering,UniversityofAdelaide,Australiabrian.
ng@adelaide.
edu.
auABSTRACTAnewdirectionofarrival(DOA)estimationmethodfortheuniformlineararrayisproposedtocopewiththescenariowherebothuncorrelatedsignalsandcoherentsignalsarepresented.
Byconstructingacentre-symmetricvirtualarraymanifoldandexploitingitspropertiescoherentsignalscanbedecorrelatedandthenestimatedwithouttheinterferenceofuncorrelatedsignals,whiletheuncorrelatedsignalsareestimatedbyutilisingtheuniquenessconditionofarraymanifold.
Thetwo-stageestimationmethodissimplebuteffective.
ItexpandstheapertureofarrayandcanestimatemoreDOAswithlessantennasthantraditionalspatialsmoothingmethods.
Ithashigherestimationprecision.
Simulationresultsdemonstratetheeffectivenessandefficiencyoftheproposedmethod.
KEYWORDS:centre-symmetricvirtualarray;directionofarrival(DOA);coherentsignals;realsignalsSimulationandAnalysisofTimeSynchronizationBasedonInter-satelliteLinkXuhaiYANGKeyLaboratoryofPrecisionNavigationandTimingTechnology/NationalTimeServiceCenter,ChineseAcademyofSciences/China,Email:yyang@ntsc.
ac.
cn+86-29-83890424&+86-29-83892309LinFangKeyLaboratoryofPrecisionNavigationandTimingTechnology/UniversityofChineseAcademyofSciences/China+86-18292485175BaoQiSunKeyLaboratoryofPrecisionNavigationandTimingTechnology/NationalTimeServiceCenter,ChineseAcademyofSciences/China+86-15249092933ABSTRACTTheinter-satellitelinkisoneofkeytechniquesintheautonomousoperationofsatellitenavigationsystem.
Inter-satellitetwo-waytimetransfercalculationformulaisbuiltinthispaperbyadoptingasynchronoustwo-waysatellitetimetransfertechnologyinGPSconstellation.
Correctivemethodofmainsystematicerrorisproposed.
Inter-satelliteasynchronoustwo-waytimesynchronizationissimulatedonthebasisofIGSpreciseephemerisandon-boardclock.
Weanalyzetheimpactofepochdomesticationofasynchronouslinkpseudo-range,initialorbit,andothermainsystematicerroronsatellitetimesynchronization.
Simulationresultsshowthatepochdomesticationofasynchronouslinkpseudo-rangeandinitialorbithavelittleimpactonsatelliteclock-error,andthusitneedn'tbetakenintoaccount.
Theerrorcausedbyrelativitytheoryeffectandmulti-pathhavelargeimpactonsatelliteclock-error,andthoseshouldbecorrectedwiththeoryformula.
KEYWORDS:inter-satellitelink,timesynchronization,GPSLowCostAdaptiveArraySignalProcessingbySubarraySelectionXiangrongWang(1)UniversityofNewSouthWales/AustraliaEmail:x.
r.
wang@unsw.
edu.
auAndrewDempster(2)UniversityofNewSouthWales/AustraliaEmail:a.
dempster@unsw.
edu.
auEliasAboutanios(3)UniversityofNewSouthWales/AustraliaEmail:elias@unsw.
edu.
auABSTRACTAdaptiveantennaarrayshavebeenproposedtomitigatestronginterferenceandmultipathinGlobalNavigationSatelliteSystems(GNSS)receivers.
However,thehighcostofanentirefront-endandlimitedsignalprocessingresourcesmakelargeantennaarrayaluxuryforGNSSreceivers.
Therefore,weproposeinthisworkalowcostadaptivearrayprocessingstrategybysubarrayselection,whilewithmaximumpreservedperformance.
ThereareonlyKfront-endsinstalledinthereceiver,thusthehardwarecostisreduceddramatically.
ThenweadaptivelyselectanoptimumK-antennasubarrayfromNcandidatesusingswitchesandthenconnectthemtothefollowingsignalprocessingnetwork.
AparameterdefinedasSpatialCorrelationCoefficient(SCC)isintroducedtocharacterisethespatialseparationbetweenthesatellitesignalandtheinterferenceandusedasacostfunctiontocalculatetheoptimumsubarray.
TherelationshipbetweentheeffectiveandtheSCCisexpressedasaclosedformulaaswell.
ThisformulashowsthattheeffectivedependsonboththenumberofselectedantennasKandtheSCCvalue,thusthereisnolinearrelationshipbetweentheeffectiveandK.
TheoptimumK-antennasubarraycanguaranteenegligibleperformancelosswhenthesatellitesignalandtheinterferencearecloseinspaceandnomorethanwhentheyarewellseparated.
An8-antennacirculararrayisusedtocollectthedatainourexperimentandonlythedatareceivedfromselectedantennasisprocessed.
Experimentalresultsshowthat(1)SCCisaneffectiveparameterforcharacterisingtheeffectofarrayconfiguration,withthesmallestvaluedenotingthebestperformanceunderthefixedsubarraysize;(2)theoptimumsubarraycanreducethehardwarecostdramaticallywithmaximumpreservedperformance;(3)giventhefixedhardwarecost,theoptimumsubarraycanachievethebestperformance.
KEYWORDS:adaptivearrayprocessing,subarrayselection,lowcost,spatialcorrelationcoefficient,effectivecarriertonoisedensityratioSession10CGNSSSoftwareReceivers1050-1230AHighAccuracyReconfigurablePlatformofMulti-modeNavigationSignalSimulatorbasedonSNWAFengXuzhe(1)CollegeofMechatronicsEngineeringandAutomation,NationalUniversityofDefenseTechnology,China0731-84575313/0731-84576475/kd805fxz@163.
comChenJianyun(2)CollegeofMechatronicsEngineeringandAutomation,NationalUniversityofDefenseTechnology,China0731-84575313/0731-84576475/kdcjy@sina.
comLinJinmao(3)CollegeofMechatronicsEngineeringandAutomation,NationalUniversityofDefenseTechnology,China0731-84575313/0731-84576475/kd805fxz@163.
comABSTRACTThispaperrepresentsahighaccuracyreconfigurableplatformofmulti-modenavigationsignalsimulatorbasedonSNWA(SoftwareNavigationWaveformArchitecture,SNWA).
Navigationsignalsimulator,astheresourcestandard,canprovideareal-likesignalenvironmentfortheresearchandtestofnavigationreceiver.
What'smore,itcanshortenthedevelopmentcycleandlowertheresearchrisks.
Withaadaptabilitytodifferentnavigationsystemsandsignalforms,thenavigationsignalsimulatorshouldbemulti-modeandreconfigurable,soitcansatisfythedemandofcompatibilityandrenewal.
Thatistosay,multi-modenavigationsignalcanbegeneratedonsamehardwareplatformbysoftwarereconfiguration.
Furthermore,thesesignalswhichindifferentmodeanddifferentfrequenciescanbeswitchedrapidlyandeasily.
ThepaperintroducestheprincipleofSNWAatfirst,andthenstudiesthearchitectureofreconfigurablenavigationsignalsimulatorbasedonSNWA,somereconfigurabledesignsforimportantmodulesarealsostated,suchasprecisetimedelay,navigationsignalgenerator,interferencesignalgenerator,etal.
Ahighresolutionsignaldelayalgorithmbasedonmultilevelre-constructdelayfiltersisinvestigated,testmethodandresultarealsogiveninthispaper.
Inaddition,thesystemperformanceevaluation,algorithmofhighaccuracydelayandparameterestimationvalidationarelistedatlast.
Thenavigationsignalsimulatorhashighadaptabilitytodifferentnavigationsystems,suchasBeidou,GPS,GLONASSandGalileo.
Itsmainperformancesareasfollows,pseudorangeuncertaintyis1mm,zerostabilizationis1cm,interchannelbiasis1cm,coherencebetweendifferentfrequenciesis2cm.
KEYWORDS:navigationsignalsimulator;multi-mode;reconfigurable;highprecision;SNWAGNSSSoftwareReceiverSamplingNoiseandClockJitterPerformanceandImpactAnalysisChenJianYun(1)CollegeofMechatronicsEngineeringandAutomationNationalUniv.
ofdefenseTechnologyChina13974980956kdcjy@sina.
comFenXuZhe(2)CollegeofMechatronicsEngineeringandAutomationNationalUniv.
ofdefenseTechnologyChina13974980956kdcjy@sina.
comZhouYonBin(3)CollegeofMechatronicsEngineeringandAutomationNationalUniv.
ofdefenseTechnologyChina13974980956kdcjy@sina.
comABSTRACTInthedesignofamulti-frequencymulti-constellationGNSSsoftwaredefinedradioreceiversisbecomingmoreandmorepopularduetoitssimplearchitecture,flexibleconfigurationandgoodcoherenceinmulti-frequencysignalprocessing.
Itplaysanimportantroleinnavigationsignalprocessingandsignalqualitymonitoring.
Inparticular,GNSSsoftwaredefinedradioreceiversdrivingthesamplingclockofanalogue-to-digitalconverter(ADC)byFPGAimpliesthatamoreflexibleradiotransceiverdesignispossible.
Accordingtotheconceptofsoftwaredefinedradio(SDR),theidealistodigitizeasclosetotheantennaaspossible.
WhereasthecarrierfrequencyofGNSSsignalisofthefrequencyofGHz,convertingatthisfrequencyisexpensiveandconsumesmorepower.
Bandsamplingmethodisacheaper,moreeffectivealternative.
Whenusingbandsamplingmethod,itispossibletosampleaRFsignalattwicethebandwidthofthesignal.
Unfortunately,astheothersideofthecoin,theintroductionofSDRconceptandbandsamplingmethodinducenegativeinfluenceontheperformanceoftheGNSSreceivers.
ADCssufferlargersamplingclockjittergeneratedbyFPGA;andlowsamplingfrequencyintroducesmorenoisetothereceiver.
Thentheinfluenceofsamplingnoisecannotbeneglected.
Thepaperanalyzesthesamplingnoise,presentsitsinfluenceonthecarriernoiseratio,andderivestherangingerrorbycalculatingthesynchronizationerrorofthedelaylockedloop.
Simulationsaimingateachimpactfactorsofsampling-noise-inducedrangingerrorareperformed.
Simulationandexperimentresultsshowthatifthetargetrangingaccuracyisatthelevelofcentimeter,thequantizationlengthshouldbenolessthan8andthesamplingclockjittershouldnotexceed60ps.
KEYWORDS:GNSSsoftwarereceivers,bandsampling,samplingnoise,clockjitter,rangingerror.
AnalysisofReceiverObservablestoSpoofingAttacksUsingSoftwareReceivers.
RyanJ.
R.
Thompson,EdizCetin,AndrewG.
DempsterUniversityofNewSouthWales,Australia.
Tel:+61293854184E-mail:r.
thompson@unsw.
edu.
au,e.
cetin@unsw.
edu.
au,a.
dempster.
@unsw.
edu.
auABSTRACTSpoofingattacks,wherefalsesatellitessignalsarebroadcasttotricktheoperationofaGNSSreceiver,presentaseriousthreattoGNSSsecurity.
Thereareanumberofreceiverobservables,suchasC/No,correlatorfunctionshape,pseudo-range,andclockoffset,tonameafew,whichwillshowvariationsduringspoofingattacks.
Theaimofthisworkistoinvestigatetheresponseoftheseobservables,usingacommercialandaMATLABbasedsoftwarereceiver,todifferenttypesofspoofingattacks.
ThisworkwillmakeuseoftheTexasSpoofingTestBattery,acollectionofscenariosforevaluatingspoofingdetectiontechniques,providedbytheRadionavigationLaboratoryattheUniversityofTexasatAustin.
Thefirstpartofthisworkisconcernedwiththeconversionofthesedatasets,whichareathighsamplingandbitrates,foruseinsoftwarereceiversusingopensourcetoolssuchasgnuradio.
Thesecondpartofthisworklooksattheresponseofthereceiverobservablesandhowreceiversettings,suchascorrelatorspacing,integrationtimes,trackingloopbandwidthsandbit-rates,affecttheirresponsetospoofing.
TheresultsoftheanalysiswillprovideinsightsintotheabilityofanautonomousGPSreceivertodetectspoofingusingonlytheobservablesgeneratedduringthenormalnavigationprocess.
ThedatasetswillalsobeconvertedforusewithacommercialGNSSreplayunittoanalyseandquantifytheeffectofquantizationandup-conversionoperationswhenreplayingthescenariostoasoftwarereceiverconnectedtoaRFfront-endoperatinginreal-time.
KEYWORDS:spoofing,softwarereceivers,C/No,clockoffset,trackingloops.
Multi-processorArchitecturesforFPGA-basedMulti-GNSSReceiversNagarajCShivaramaiahAndrewGDempsterAustralianCentreforSpaceEngineeringResearch,UNSW,AustraliaPh:+61(2)93856702Fax:+61(2)93137493email:nagaraj@unsw.
edu.
auABSTRACTThispaperanalysesmulti-processorarchitecturesforsoftwaredefinedGNSSreceiversimplementedusingFPGA-basedSoCtechnology.
Severaldesignarchitecturesarestudiedinthepaperstartingfromasinglehigh-endprocessorbasedsolutionononeendofthespectrumtoacoarse-grainedarchitecturewithmultiplelow-endsoft-coreprocessorsontheotherend.
ConsideringtheavailabilityoftherangeofprocessorsinthecurrentFPGAdevices,thechallengesandthefeasibilityofthesedesignarchitecturesarediscussed.
Whilethehorse-poweroftheFPGA-basedhigh-endprocessorsbecomesachallengeforsimultaneousprocessingofmultipleGNSSsignals,thearchitectureintricaciesposeotherinterestingchallengesforthecoarse-grainedarchitectures.
Theinter-signalandinter-processorinteractionandrelatedintricaciesinthemulti-processorarchitecturesneedsathoroughanalysisofthedebatingdesignpartitionmethodologies.
Thepaperwilltouchonthesetopicsandproviderecommendationsbasedoninitialresultsanduse-cases.
KEYWORDS:Multi-GNSS,Receiverdesign,Multi-processor.
MitigationofStandingMultipathBasedonAdaptiveFilteringXuanyingZhouSchoolofScience,NationalUniversityofDefenseTechnology,ChinaPhone:+86-731-84573260,Fax:+86-731-84574234,emailaddress:djulia1020@gmail.
comBoChenSchoolofScience,NationalUniversityofDefenseTechnology,ChinaPhone:+86-731-84573260,Fax:+86-731-84574234,emailaddress:chenbo0354@yahoo.
comJingYaoSchoolofScience,NationalUniversityofDefenseTechnology,ChinaPhone:+86-731-84573260,Fax:+86-731-84574234,emailaddress:isabellayj@gmail.
comJiyingLiuSchoolofScience,NationalUniversityofDefenseTechnology,ChinaPhone:+86-731-84573260,Fax:+86-731-84574234,emailaddress:gene0572@163.
comABSTRACTGEOsatelliteshavebeenusedinsatellitenavigationsystemssuchasBeidouandaugmentationsystemsofGPS.
BecauseGEOsatellitesarealmoststationaryrelativetotheEarth,somemultipathsignalsarevaryingveryslowly.
Thiscausesthe"standingmultipath",whichdramaticallydecreasestheaccuracyofpositioning.
Someapproachescombinedbyradiofrequencyandpost-processingmethodshavebeenproposedtomitigatethestandingmultipath.
Thepost-processingmethodscanbeclassifiedintotwotypes:thetime-domainandfrequency-domainprocessing.
WhilethefrequencyofmultipathoftheGEOsatelliteislow,whichmaylapoverthoseofionosphere,troposphereandsoon,theyaredifficulttoseparateinfrequencydomain.
Italsoneedsthedatainatleastoneperiodtocalculateitsspectrum.
Forthemultipathofone-dayperiod,thefrequencydomainmethodneedsawholedaytoinitialization.
Thetimedomainprocessingcanbedoneinawaycalledcodenoiseandmultipath(CNMP),whichwasproposedforrealtimeprocessinginWideAreaAugmentationSystem(WAAS).
Becausemultipathinthecarrier-phasemeasurementisquitesmall,themultipathinpseudorangecanbecancelledinthesimilarwayaspseudorangesmoothing.
Unfortunately,inourexperimentsitisfoundthatthesmoothedcodeinCNMPstillhassomeerrorleft,whichhasthesameperiodsasstandingmultipath.
Asanimprovement,weproposedacoefficient-adaptivefilter.
Thecoefficientsofthisfilterareestimatedaccordingtothemodelingofstandingmultipathdatabymethodsoftimeseriesanalysis.
AnumericalverificationwascarriedoutbyusingWAASdata.
Theresultsindicatethattheproposedmethodcansignificantlysuppressthestandingmultipathandimprovetherateoffilteringconvergence.
KEYWORDS:standingmultipath,adaptivefiltering,GEOsatellites,time-frequencyanalysisSession11AMultiGNSSDataProcessing1330-1530ImprovedHighPrecisionGNSSPositioningwithNewSatellitesandSignalsNicholasTalbotResearchFellow,TrimbleNavigation,AustraliaPh:+61(0)395187464;Fax:+61(0)395187401;nick_talbot@trimble.
comTimoAllisonEngineeringManager,TrimbleNavigation,UKtimo_allison@trimble.
comKendallFergusonSoftwareEngineer,TrimbleNavigation,USAkendall_ferguson@trimble.
comRodrigoLeandroEngineeringManager,TrimbleNavigation,Germanyrodrigo_leandro@trimble.
comGangLuDevelopmentEngineer,TrimbleNavigation,USAgang_lu@trimble.
comStuartRileyResearchFellow,TrimbleNavigation,USAstuart_riley@trimble.
comStephanSeegerDevelopmentEngineer,TrimbleNavigation,Germanystephan_seeger@trimble.
comRalfStolzDevelopmentEngineer,TrimbleNavigation,Germanyralf_stolz@trimble.
comABSTRACTTheworldisonthecuspofasignificantenhancementtotheconstellationofGlobalNavigationSatelliteSystems.
By2015,approximately90navigationsatelliteswillbeinorbitaroundtheearth;by2020,thenumberofsatelliteswillincreaseto120ormore.
Today,intheAsia-Pacificregion,30ormoreGNSSsatellitesareroutinelyinviewabovethelocalhorizon–thisprovidesanopportunitytoexplorethebenefitsofusingsignalsfromtheChineseBeiDou;JapaneseQZSS;RussianGLONASS;andUSGPSconstellations,forprecisepositioning.
PreciseGNSSpositioningtechniquesthatdelivercentimetre-levelaccuracyarenowwidelyusedacrossabroadspectrumofapplications,amongthemanyare:precisionagriculture,construction,machinecontrol,andsurveying.
Theperformanceofhigh-precision,Real-TimeKinematic(RTK)positioningisoftenmeasuredintermsofinitializationtime,accuracyandsolutionreliability,andtheseparametersarestronglyrelatedtotheprevailingsatellitegeometry.
ThispaperexaminesthebenefitsandchallengesofusingthelatestGlobalNavigationSatellitesignalsforprecisepositioning.
SeveralRTKtestswereconductedwithandwithouttheinclusionofnewsatellitemeasurements.
Theresultsindicatethatadditionalsatellitesproducesubstantialimprovementinthestandarddeviationandrangeofthepositionerrors.
Theinclusionofnewsatellitesystemmeasurementsisshowntoparticularlystrengthentheheightcomponentestimatesandthesolutionintegrity.
Furthermore,thespatialdistributionofthesatellitesincreasestheabilityofuserstooperateinchallengingtrackingenvironmentswherepartsoftheskyareobstructed.
KEYWORDS:RTK,Precise-Positioning,BeiDou,QZSS,GLONASSGNSSSatelliteSelectionWithIntegrityConsideration:ACaseStudyintheDifferentialPositioningModeLiangLIAcademyofOpto-electronics,ChineseAcademyofScience,Beijing,China,100094(+86)-010-82178653,lilianghrb@gmail.
comHongYUANAcademyofOpto-electronics,ChineseAcademyofScience,Beijing,China,100094(+86)-010-82178851,yuanh@aoe.
ac.
cnChaoYUAN,DongyanWEI,RuidanLUOAcademyofOpto-electronics,ChineseAcademyofScience,Beijing,China,100094(+86)-010-82178653,yuanchao_yx@aoe.
ac.
cnABSTRACTWiththepromisingfutureofGlobalNavigationSatelliteSystem(GNSS),thehighprecisionLocationBasedServices(LBS)basedondifferentialpositioninginhighdensityurbanareaismoreenviablethanever.
Astrackingallavailablesatellitessimultaneouslyintheuserreceiverleadsunacceptablecomputationburden.
SatelliteselectionthereforewereproposedtoreleasethecomputationlimitationwithselectingtheminimumoperationsatellitessettomaintainendurablepositioningaccuracyundertheleastDilutionofPrecision(DOP)losscriterion.
Mostoftheexistingsatelliteselectionmethodsarebasedonsingle-pointpositioningmodel.
Asthedifferentialresidualerrorsvarywithtime,measurementqualityshouldthereforebeconsideredintheselectioncriterion.
Furthermore,anotherchallengeforsatelliteselectionisthesignalinterference/deformationintheurbanareaasmultipatherrorwillbedominant,theintegritymonitoringneedtobeusedinsuchcase.
Anovelsatelliteselectionalgorithmwithusingtotalweightingscoremethodispresentedtoselecttheoptimalsatellitessetwithsatisfyingtherequirementfrombothaccuracyandintegrity.
TheselectionthresholdvaluesforweightedDOPandintegrityisdeducedfromtheRequiredNavigationPerformance(RNP).
Theperformanceoftheproposedmethodwasvalidatedwithusingthereal-worlddatawhichwascollectedinBeijing.
Theexperimentresultsdemonstratethatweightedsatellitesselectionmethodcouldprovidenotonlytheminimumaccuracyandintegrityloss,butalsowithareasonablecomputationburden,andthuscouldbeanedgeoptionforthedifferentialpositioningintheurbancanyonarea.
KEYWORDS:GNSS;differentialpositioning;satelliteselection;accuracy;integrityEffectofSatelliteSelectionofGPSandGLONASSbyHighAccuracyPositioningwithRovingAntennaTakahiroIkedaTransportationEngineeringandSocio-Technology,GraduateSchoolofScienceandTechnology/NihonUniversity/JapanPhone&Fax:+81-47-469-8147Email:ikeda.
takahiro@trpt.
cst.
nihon-u.
ac.
jpTatsunoriSadaDepartmentofTransportationEngineeringandSocio-Technology,ScienceandTechnology/NihonUniversity/JapanPhone&Fax:+81-47-469-8147Email:sada@trpt.
cst.
nihon-u.
ac.
jpTetsuhiroIshizakaDepartmentofTransportationEngineeringandSocio-Technology,ScienceandTechnology/NihonUniversity/JapanPhone&Fax:+81-47-469-8147Email:ishizaka.
tetsuhiro@nihon-u.
ac.
jpABSTRACTGLONASSandothersatellitesystemswaslaunchtooperateandhascometobeusedinrecentyears,althoughGPShadmainlyused.
Therefore,theimprovedavailabilityofhighaccuracypositioningisexpectedinurbanandmountainousareasbyusingGLONASSwithGPS.
However,theincreaseofsatellitesmaycausetheincreaseofmultipath;itisrequiredtobeforehandselecttheGNSSwithoutmultipathbycheckingthestatusofsatelliteradio.
TheauthorsproposedtheselectionmethodofsatellitesignalwithmultipathusingthedistancechangeofthecarrierwaveL1andL2,inadditiontothesignalstrengthofthesatellite.
Theeffectofhighaccuracypositioningwasverifiedbythesatelliteselectiontobeusedforpositioning.
Intheexperiment,GNSSsatellitesignalwerereceived.
Anditsobservationpointsweresetonthecourseformovinginordertoobservethevariousambientconditions.
Asaresult,satellitesignalaffectedbymulti-pathwasconfirmedbyefficientcombinationofdistanceandsignalstrengthofthecarrierwavechanges.
Inaddition,positioningratiooffixedsolutionwasimprovedbythesatelliteselection.
KEYWORDS:GPS,GLONASS,highaccuracypositioning,multipath,carrierwaveL1andL2ReceiverInter-ChannelBiasSearchTechniqueforReal-TimeKinematicGPS/GLONASSHeeSungKimSchoolofElectronics,Telecomm.
,andComputerEng.
/KoreaAerospaceUniversity/Korea82-2-300-0148,hskim07@kau.
ac.
krJeYoungLeeSchoolofElectronics,Telecomm.
,andComputerEng.
/KoreaAerospaceUniversity/Korea82-2-300-0148,jeylee@kau.
ac.
krKwangHoChoiSchoolofElectronics,Telecomm.
,andComputerEng.
/KoreaAerospaceUniversity/Korea82-2-300-0148,sahnhara@kau.
ac.
krHyungKeunLeeSchoolofElectronics,Telecomm.
,andComputerEng.
/KoreaAerospaceUniversity/Korea82-2-300-0131,hyknlee@kau.
ac.
krABSTRACTItisanticipatedthatthenumberofvisiblenavigationsatelliteswouldincreasedramaticallyinthenearfuturebymultipleGNSSconstellations.
Currently,mostrepresentativeexamplesofmultipleconstellationsincludeGPSandGLONASS.
However,itisnoteasytointegratethetwodifferentsystemssincetheyhavedifferenttimereferences,coordinatesystems,andsignalcharacteristics.
Especially,signalgenerationtechniqueknownasFDMA(frequencydivisionmultipleaccess)utilizedinGLONASScausesreceiverICBs(inter-channelbiases).
ICBsvaryamongthereceiversfromdifferentmanufacturersandvaryamongthedifferentchannelsofareceiver.
ThispaperinvestigatesreceiverICBsearchtechniquebasedonLAMBDA(least-squaresambiguityresolutiondecorrelationadjustment)methodforRTK(real-timekinematic)GPS/GLONASS.
AlthoughreceiverICBwhichexistsineachGLONASSchannelarewithinonewavelength,itcancausedegradationofpositioningperformanceandpreventambiguityresolutioninRTK.
TosearchreceiverICBs,thedecorrelatedintegerambiguityestimationmethodisutilized.
Next,theperformanceofICBsearchandambiguityresolutionisfurtherimprovedutilizingcorrelatedintegerambiguityestimations.
Toevaluatetheperformanceoftheproposedtechnique,staticandkinematicexperimentsareperformedbetweenheterogeneousGNSSreceiversinreal-timemode.
KEYWORDS:GPS/GLONASS,RTK,Inter-ChannelBias,AmbiguityResolution,LAMBDAAGeneralisedFormationofGNSSObservationalModelsforMulti-ConstellationandMulti-frequencyDataProcessingShengfengGu,ChuangShi,YidongLouWuhanUniversity,China;emails:gsfjay@163.
com;shi@whu.
edu.
auYanmingFengQueenslandUniversityofTechnology,Australia,email:y.
feng@qut.
edu.
auABSTRACTTheexistingGNSSdataprocessingmodelsandmethodsarepredominatelybaseddual-frequencycodeadphasesignals.
Forinstance,bydefault,dual-frequencycodeand/orphaseGPSmeasurementsarelinearlycombinedtoeliminatetheeffectsofionospheredelaysinpreciseorbitdetermination(PPP)andprecisepointpositioning(PPP).
Thistraditionaltreatmentexhibitslimitationswhenprocessingsignalsofthreeormorefrequenciesandfrommultipleconstellations.
ThispaperexploresageneralisedformationofGNSSobservationalmodelsthatareapplicableforanynavigationsystemsandanynumberofcarriersandcansuitbothsingleandmulti-sitedataprocessing.
Forthesynchronizationbetweendifferentsystemsandsignals,uncalibratedsignaldelays(USD)aremoregenerallydefinedtocompensatethesignalspecicosetsincodeandphasesignalsrespectively.
Inaddition,theionosphericdelaysareincludedintheparameterizationwithanelaborateconsideration.
Basedontheanalysisofthealgebraicstructures,thisgeneralizedmodelisfurtherrefinedwithasetofconstrainstoregularizethedatumdeciencyoftheobservationequationsystem.
Withthisnewmodel,uncalibratedsignaldelays(USD)andionospheredelaysarederivedfromalargesetforGPSandCOMPASSdata.
Numericalresultsdemonstratethat,withalimitednumberofstations,theuncalibratedcodedelays(UCD)aredeterminedtoaprecisionofabout0.
1nsforGPSand0.
4nsforCOMPASSsignals,whiletheuncalibratedphasedelays(UPD)forL1andL2aregeneratedwith37stationsevenlydistributedinChinaforGPSwithaconsistencyofabout0.
3cycles.
Additionalexperimentsconcerningtheperformanceofthisnovelmodelinpointpositioningwithmixed-frequenciesofmixed-constellationsareanalysed,inwhichtheUSDparametersarexedwiththegeneratedvaluesfromthenetwork.
Theresultsareevaluatedintermsofbothpositioningaccuracyandconvergencetime.
KEYWORDS:Multi-GNSS;Multi-frequency;UncalibratedSignalDelay;Ionosphericdelay,PrecisePointPositioningSession10BNonGNSSPositioning1330-1530Locata,aNon-GNSSPositioningTechnology:FromMinestotheMassesChrisRizosSchoolofSurveying&GeospatialEngineering,UNSW,Australia+61-2-93854205(T),+61-2-93137493(F),c.
rizos@unsw.
edu.
auABSTRACTUntilrecentlytherehavebeennoviablealternativestoGNSSthatprovidethecombinationofhighaccuracypositioning(centimetre-to-several-decimetre),goodcoverage,lowreceivercost,andeaseofuse.
LocataisanAustralianpositioningtechnologysolutionthatisapromisingoptiontoeitheraugmentGNSSwithextraterrestrialsignalswheretheskyviewislimitedasinthecaseofdeepopen-cutmines,ortoreplaceGNSSaltogetherinindoorandurbanenvironments.
UNSWhasbeenconductingLocataresearchforoveradecadeinavarietyofsensorscenarios,fromGNSS+Locata,multi-sensormodes,andLocata-only.
Locataappearsassuredofafutureasacommercialpositioningtechnology,nowintegratedwithinLeica'sminingpositioningproducts.
AlthoughLocatahasnowdemonstrateditscapability,anddespiteithavingseveralveryinnovativefeatures,thetransitionfrombeingapositioningsystemfornicheapplications(suchasforopen-cutmines)tobeingabletoaddressthe"ubiquitouspositioning"marketisanextremelydifficultone.
FirststepsinpromotingLocataasaviablepositioningtechnologyforuseinurban/indoorenvironmentsweretakeninOctober2012whenUNSW,LPIandLocatacooperatedinaSydneyHarbourexperiment.
ThenextstepistobuildapermanenttestnetworktoservicetheSydneydowntownarea.
ThefundamentalobstacleinLocatabecomingacceptedasanaugmentation/alternativetoGNSSistheclassic"chicken-and-the-egg"challenge.
NoserviceproviderwillinvestindeployingtheLocatasignaltransmittersunlessthereareusers;yetcommercialuserdeviceswillnotbedevelopedunlessthereispre-deployedLocatasignaltransmissioninfrastructure.
ThispaperdiscussestheLocatatechnologyfromtheperspectiveofmassmarketapplications,includingthenotionsofaLocata"ecosystem",thevalueoftechnologydemonstrationplatforms,andtherespectiverolesoftechnologypioneers(orearly-adopters),governmentagencies(throughR&Dpoliciesandincentives)andresearchinstitutions(bothinprogressingfundamentalresearchandprovidingindependentassessmentofthetechnology).
KEYWORDS:Locata,alternativePNT,GNSS,indoorpositioning,positioninginfrastructureANovelDeformationMonitoringSystemBasedonPseudoliteTechnologyTaoWang,QiuWu(1)CentreofCommunicationandTT&C/ChongqingUniversity/China02365105925-614wt1977@cqu.
edu.
cnAndrewGDempster(2)ACSER/UNSW/Australia0293856890a.
dempster@unsw.
edu.
auABSTRACTThispaperputsforwardanoveldeformationmonitoringsystembasedonpseudolitetechnology.
Thissystemconsistsofonereferencestation,threepseudolitesandmanyobservationpointsinstalledonthestructure.
Thereferencestationradiatestworadiofrequencyspreadspectrumsignalsmodulatedbythesamepseudonoisesignal.
Thepseudolitesareactivedelay-repeaters.
Theamplifierofthepseudoliteisusedtoadjusttheamplitudeofthesignalarrivedattheobservationpointtoeliminatetheinfluenceoffar-neareffectexistedinCDMAsystem.
Thedelaylineofthepseudoliteisusedtomakethepseudonoisecodephasedifferencebetweenanytwosignalsarrivedattheobservationpointlargerthanonechipwidthinordertodistinguishthemfromeachother.
Theobservationpointreceivedonepurelowfrequencyspreadspectrumsignalandonehighfrequencyspreadspectrumsignalwhichisamixedsignaloffoursignalscomingfromreferencestationandthreepseudolites.
Theobservationpointusescarrierrecoveringcircuitsuchassquarelooptorecoverthecarrierofthelowfrequencyspreadspectrumsignalandthenusesthiscarriertomixwiththespreadspectrumtorecoverthepseudonoisecode.
Thenwecandelaythisrecoveredpseudonoisecodeandmixitwiththereceivedhighfrequencyspectrumsignaltorecoverthecarriersignalsfromthereferencestationandthreepseudolites.
Wecanusephasedetectorstocalculateoutthephasedifferencebetweenanypseudoliteandreferencestation.
Wecanconstructonelinearequationgrouptousethephasedifferencevariationstocalculateoutthethreedimensionaldeformationofobservation.
ComparedwithLocataPseudolitepositioningtechnology,there'snoneedofclocksynchronizationcircuitandpseudolitenoisecodeacquisitionandtrackingloop,andalsothepseudolite'circuitisrelativelysimplified.
Inshort,thissystemismorerobustbutthecosthasdecreasedsharply.
KEYWORDS:Pseudolite,deformationmonitoring,pseudolitenoisecode,activerepeaterCooperativeWirelessSensorNodesbasedAcquisitionforMobileLocationServices(MLoC)AliSarwarSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854185,Fax:+61293137493Email:ali.
sarwar@student.
unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineering,UniversityofNewSouthWales,AustraliaPhone:+61293854205,Fax:+61293137493,Email:c.
rizos@unsw.
edu.
auABSTRACTPositioningbasedonWirelessSensorNodes(WSNs)hasproveneffectiveforassistingGNSSoperationsinindoorenvironments.
Basedonthereceivedsignalstrengthindicator,linkqualityindicatorsandindividualfixednodelocation"slices"(containedinacumulativesignatureindicesdatabaseateachnode)cansupplyfrequencyoffset,rangeandcoordinateassistanceforlocationbasedservicesforindoorcoverageoroutdoor(GNSS)coveragescenarios,throughperiodictransmissiontosurroundingnodes.
Sinceeachnodestoresadatabaseofitsownaswellasneighbouringnodelocation"slices",acumulativeoutputstreamcontaininglocationcoordinatesofamobilenodeofinterestiscalculatedandinputthroughadynamicallychosenpointofinterconnectintotherovernodeforlocationdetermination.
TherovernodeisasmartphoneinterfacedtoaWSN,displayingthelocationinformationandprovidingassistanceparameterstotheinbuiltGNSSchipset.
Howeverproblemssuchasmisalignedtransceivertime-syncing,thermalnoiseandbroadcasterror,incorrectparameterdecodingandprocessorinitialisationdelayatafixedormobilesensornodecanintroducearbitraryerrorsinGNSScalculations.
Thiscanadverselyaffecttheresultantlocalisationperformance.
Inthispaperthedifferenterrortypes,theirrespectiveeffectsandresourceconstraintconsiderationsarediscussed.
Toaddresssuchproblemsasystemcomprisingsevenfixedstand-aloneWSNisproposedforindoorpositioningandcomparedagainsttraditionalGNSS,Assisted-GNSS(AGNSS),andWSN-AGNSStechniques.
Thispaperpresentstestresultsdemonstratingcm-levelaccuracy,anddiscussesresponsesensitivityandreliabilityintheeventofpartialnodemalfunction.
Empiricalmeasurementsbasedonreceivedsignalstrength(RSS)(neighbor-to-neighbour),linkqualityindications(inoverlappingcoverage)withdiversegeographicalgeometryarepresented.
Systemarchitecture,codeprocessingworkflowandRSS-basedlocalisationmethodsaredescribed.
TechnicaldetailsoftheIEEE802.
15.
4dprotocol,physicalandmediumaccesscontrollayerswithrespecttoMICAzWSNsarebrieflydiscussed.
RovertrackingexperimentswereconductedinanenclosedbuildingcorridorsimulatingadifficultindoorGNSSenvironmentandresultsarepresented.
Signalattenuationandabsorptionparameterssubjecttodifferentmaterialsareanalysed.
Thesystemdemonstratesslightlyimprovedtime-to-first-fix,time-syncingandclockinginformationwithouttheprocessingcostassociatedwithaforementionedtechniques.
WSNnetworkcanberapidlydeployedandcanefficientlytrackamobilerovernode.
Applicationsofinterestwillbediscussed.
KEYWORDS:WSN,MLoC,TTFF,Sensitivity,Accuracy,AvailabilityPerformanceEnhancementofMEMSNavigationSystembasedonANFISInferenceSystemLingZhang(1)NavigationResearchCenter,NanjingUniversityofAeronauticsandAstronautics,China+862584892304-810&+862584892304-819,zhanglingsnowman@nuaa.
edu.
cnZhiXiong(2)NavigationResearchCenter,NanjingUniversityofAeronauticsandAstronautics,China+862584892304-804&+862584892304-819,Xznuaa@nuaa.
edu.
cnJianyeLiu(3)NavigationResearchCenter,NanjingUniversityofAeronauticsandAstronautics,China+862584892304-801&+862584892304-819,ljyac@nuaa.
edu.
cnJizhouLai(4)NavigationResearchCenter,NanjingUniversityofAeronauticsandAstronautics,China+862584892304-807&+862584892304-819,laijz@nuaa.
edu.
cnABSTRACTCharacterizedbysmallvolume,lowcostandlowpower,MEMSinertialsensorsarewidelyconcernedandappliedinnavigationresearch,environmentalmonitoring,militaryandsoon.
Especiallyinindoorandpedestriannavigation,itseasily-portablefeatureseemsparticularlyindispensableandimportant.
However,MEMSinertialsensorisinbornlow-precisionandimpressionable,andsometimesgoesagainstaccuratenavigationorevenbecomeseriouslyunstablewhenworkingforaperiodoftimeandtheinitialalignmentandcalibrationareinvalid.
Athoughtofadaptiveneuro-fuzzyinferencesystem(ANFIS)isreliedon,andanassistivecontrolmodulatedmethodispresentedinthispaper,whichisnewlydesignedtoimprovetheinertialsensorperformancebyblackboxcontrolandinference.
Therepeatabilityandlong-timetendencyoftheMEMSsensorsaretestedandanalyzedbyALLANmethod.
TheparametersofANFISmodelsaretrainedusingreasonablefuzzycontrolstrategy,withhigh-precisionnavigationsystemforreferenceaswellasMEMSsensorproperty.
TheMEMSerrornonlinearityismeasuredandmodulatedthroughthepeculiarityofthefuzzycontrolconvergence,toenhancetheMEMSfunctionandthewholeMEMSsystemproperty.
Performanceoftheproposedmodelhasbeenexperimentallyverifiedusinglow-costMEMSinertialsensors,andtheMEMSoutputerroriswellcompensated.
ThetestresultsindicatethatANFISsystemtrainedbyhigh-precisionnavigationsystemcanefficientlyprovidecorrectionstoMEMSoutput,andmeettherequirementonnavigationperformance.
KEYWORDS:MEMS,adaptiveneuro-fuzzyinferencesystem(ANFIS),fuzzycontrolstrategy,errormodulation6UCubeSatsatelliteforGNSSRadioOccultationAndrewDempsterAustralianCenterforSpaceEngineeringResearch,UniversityofNewSouthWhales,AustraliaEmail:a.
dempster@unsw.
edu.
auLilyQiaoAustralianCenterforSpaceEngineeringResearch,UniversityofNewSouthWhales,AustraliaEmail:l.
qiao@unsw.
edu.
auSebastianChaouiAustralianCenterforSpaceEngineeringResearch,UniversityofTechnologySydney,AustraliaEmail:sebastian.
chaoui@hotmail.
comABSTRACTGNSSRadioOccultation(RO)isaremotesoundingtechniquewhichutilisesradiowavesemittedbyGNSSsatellitesthatbecomeoccultedthroughtheionosphere.
GPSreceiversinLEOsatellitescouldreceivethesesignalsandprocessthemfortheretrievalofkeyatmospheric/climateparameters.
Recenttechnologicaldevelopmentspermithighlyminiaturisedreceiversthatprovidehighqualityscientificdataforionosphericstudies,thesereceiversarecompatiblewiththeCubeSatformfactor.
TheaimofthestudyistoverifywhetheralargenumberofCubeSatsthatarecheaptoproducebutyieldlessaccurateresultscouldcompetewithasmallerconstellationoflarger,moreexpensivesatellitesthatwereabletoproducemoreaccuratedatasets.
TheQB50program'sUNSWECO2UCubeSatisdesignedbyACSERandisplannedtoflyaROpayloadin2015.
ECOwillbeaprototypethataidsthedevelopmentofaconstellationoflarger6UCubeSats.
KEYWORDS:CubeSatConstellation,GNSSRO,GPSreceiverSession11CInterference+AviationandAvionics1330-1530GNSSSignalCancellationforEnhancedInterferenceDetectionandLocalizationGiulioGabelliUniversityofBologna,ItalyTel:+390512093396e-mail:giulio.
gabelli2@unibo.
itEdizCetin,RyanJ.
R.
Thompson,AndrewG.
DempsterUniversityofNewSouthWales,AustraliaTel:+61293854206e-mail:e.
cetin@unsw.
edu.
au,r.
thompson@unsw.
edu.
au,a.
dempster@unsw.
edu.
auGiovanniE.
CorazzaUniversityofBologna,ItalyTel:+390512093054e-mail:giovanni.
corazza@unibo.
itABSTRACTAplethoraofservicesandapplicationsrelyontheGlobalNavigationSatelliteSystems(GNSS)positioningandsynchronizationcapabilities.
GNSSsignals,however,aresusceptibletointerferenceduetotheirweakpowerlevels.
TheGNSSEnvironmentalMonitoringSystem(GEMS)IIprovidesthecapabilitytodetectandgeo-locateinterferersinrealtimeinagivenarea.
Itconsistsofanetworkofspatiallyseparatedtime-synchronizedsensornodesconnectedtoacentralprocessingunit.
InterferencelocalizationisachievedbyhybridAngle-of-Arrival(AOA)andTimeDifferenceofArrival(TDOA)techniques.
InordertocalculatetheTDOA,datacollectedatdifferentsensornodesarecross-correlated.
Thishoweverlimitsthelevelatwhichtheactualinterfererscanbedetectedsincethecross-correlationnotonlycontainspeaksduetotheinterferersbutalsopeaksduetotheGPSsatellitesthemselves.
Theseunwantedpeakscouldbemistakenforweakinterferershencedegradingtheinterferencedetectionandlocalizationperformance.
Inthispaper,anovelsolutionfortheeliminationofthecross-correlationpeaksduetotheGNSSsignalsisproposed.
Acompleteanalysisofthecross-correlationbetweentheGNSSsignalsatdifferentreceiversisprovided,anddifferentsolutionstotheinterferencecorrelationestimationproblemareproposed.
Thecross-correlationoftheinterferingsignalisestimatedbyadaptivelycancellingthecorrelationduetotheGNSSsignals,whichiscontinuallyestimateduntiltheinterferenceisdetected.
AcompleteanalysisoftheproposedsolutionsiscarriedoutbymeansoftheoreticalaswellasnumericalsimulationsbasedonSpirentdata.
Resultsintermsofcross-correlationfunctionandTDOAestimationaccuraciesareprovided.
ItisshownhowtheperformanceoftheproposedalgorithmdependsontheJammer-to-NoiseRatio(JNR),ontheInterference-to-GNSS-SignalRatio(JSR),andontheinterferencesignaldynamics.
Finally,recommendationsforreal-timeimplementationarealsoprovidedinordertomaximizethesystemcomputationalefficiency.
KEYWORDS:interference,localization,TDOA,cross-correlation.
ApplicationofCollectiveDetectioninSpoofingScenariosJoonWaynCheongAustralianCentreforSpaceEngineeringResearchattheUniversityofNewSouthWales/Australia+61293856702/cjwayn@unsw.
edu.
auLiLiCollegeofElectronicEngineeringattheTianjinUniversityofTechnologyandEducation+61451387618/lili7312@gmail.
comJinghuiWuAustralianCentreforSpaceEngineeringResearchattheUniversityofNewSouthWales/Australia+61293854206/jinghui.
wu@unsw.
edu.
auAndrewG.
DempsterAustralianCentreforSpaceEngineeringResearchattheUniversityofNewSouthWales/Australia+61293856890/a.
dempster@unsw.
edu.
auChrisRizosSchoolofSurveyingandGeospatialEngineeringattheUniversityofNewSouthWales/Australia+61293854205/c.
rizos@unsw.
edu.
auABSTRACTCollectiveDetectionisanalgorithmtypicallyusedinthefieldofweaksignalacquisitiontoenhancethesignaldetectionrate.
ThecoreideaofCollectiveDetectionistoprojectcorrelationvaluesinthecodephasedomainontothepositiondomainsuchthatthecorrelationvaluesfromvarioussatellitechannelsarecombinedtoformastrongerpeakwithrespecttothecross-correlationnoisefloor.
Manyexistingconsiderationsofspooferstypicallyinvolvearepeaterora"recordandreplay"attackonthevictimreceiver.
Manysimpleworkaroundshavebeenproventomitigatetheseprimitiveattacks.
However,ithascometolightinrecentyearsthatmodernspooferscanbemuchmoresophisticatedsuchthatmanyoftheseexistingworkaroundsarenolongereffectiveindefendingthevictimreceiveragainstspoofing.
Thispaperspecificallytargetssuchsophisticatedattacksforinvestigation.
ThemainaimofthispaperistodiscussthepossibleamalgamationofCollectiveDetectionwithaconventionalspoofingdetectiontechniquetoachievehigherratesofdetectionofaspoofingsignal.
Inaddition,thispaperwillalsodiscusstheadaptationoftheCollectiveDetectionconceptforspooferlocalisation.
Somepreliminaryexperimentalresultsshowthefeasibilityofsomeoftheproposedmethods.
KEYWORDS:CollectiveDetection,Anti-Spoofing,SpooferLocalisation,SpoofingDetectionUASPhotogrammetryusingRealTimePreciseGNSSCameraLocationsGavinDochertyPositionPartners/AustraliaPh:0400354873email:gdocherty@positionpartners.
com.
auABSTRACTTheconceptofphotogrammetryhasbeenaroundsincetheadventofmodernphotographyandcanbedatedbacktothemidnineteenthCentury.
AnalyticalphotogrammetryhasbeenusedtoaccuratelymodelandmaptheEarthsterrainsincethenineteensixties.
Onlyrecentlyhasdigital"SoftCopy"photogrammetrycomeofagewhichhasallowedpractitionerstoproducepointcloudsofmillionsofpointsthatrepresentthethreedimensionalgeometryofthefeaturescapturedinthephotography.
Typically,thistypeofphotogrammetrywouldbecarriedoutbyfullsizemannedaeroplaneswithspecialmountedcamerasandupuntilnowithasbeennecessarytousewell-coordinatedphotocontrolpointspositionedstrategicallyonthegroundsurfacetoallowforfeaturematchingandaccuratemodellingofthesurface.
ModernSurveyorsarenowoptingformorecontrolovertheirownsurveyingmissionsbyusingUnmannedAerialSystems(UAS's)wheretheyhavetheadvantagesoflowlevelflight(belowclouds)andrelativelyquickmobilisationtimes.
ThispaperexaminestheprinciplesofdevelopmentofRealTimeKinematic(RTK)positioningoftheUAS'scameralocationduringflightsnegatingtheneedforgroundcontrolpoints.
KEYWORDS:UAV,UAS,NTRIP,CORS,RTKAircraftDetectionExperimentalResultsforGPSBistaticRadarusingPhased-arrayReceiverChowYiiPuiSchoolofElectrical&ElectronicEngineering,UniversityofAdelaideGate5,FromeRd,SA5005Tel:+61883038314Email:mpss@eleceng.
adelaide.
edu.
auMatthewTrinkleSchoolofElectrical&ElectronicEngineering,UniversityofAdelaideGate5,FromeRd,SA5005Tel:+61883034708Email:mtrinkle@eleceng.
adelaide.
edu.
auABSTRACTAstudyhasbeenmadeintousingGPSsignalastheilluminatorofopportunityofapassivebistaticradarfortargetdetection.
DuetothelowtransmissionpowerlevelofGPSsignal,itcanonlybeusedtodetecttargetoflargesizesuchasaircraft,assumingthesystemutiliseshighsensitivityreceiverthatuseslargescaleantennaarraysandsufficientlylongintegrationperiods.
Aphased-arrayreceiverthatconsistsof32dualpolarisedelementswasdevelopedfortheradarsystemtoincreasethedetectionperformanceandsearchforaircraftreflectionsacrossalldirection-of-arrivalsusingtheconventionalbeamformingtechnique.
AninitialaircraftdetectionexperimenthasbeenpreviouslymadeintoinvestigatetechniquessuchasarrayorientationandchannelphasecalibrationusingGPSsignalsasthecalibratingsourcesandalsodirectpathandmultipathinterferencemitigationtechniqueusingWeinerfilter.
Thedetectionprocesswillalsobeinvolvedwithusingthecorrelationbetweendatathatisdigitisedbythefront-endsandthePRNcodethatisdirectlyacquiredbythephased-arrayreceiverinsteadofthelocallygeneratedPRNcode.
FurtheraircraftdetectionexperimentwillbeconductedbeforetheendofMarchtostudytheperformanceofusingGPSsignalforaircraftdetectionandtheresultswillbepresented.
KEYWORDS:PassiveBistaticRadar,Phased-array,AircraftDetectionSensitivityAnalysisoftheAirborneCCDMonitorforGAST-DYoungsunYunKoreaAerospaceResearchInstitutePhone:82-42-860-2798,Fax:82-42-860-2789,Email:ysyun@kari.
re.
krJeonghoChoKoreaAerospaceResearchInstitutePhone:82-42-860-2407,Fax:82-42-860-2789,Email:jcho@kari.
re.
krMoon-BeomHeoKoreaAerospaceResearchInstitutePhone:82-42-860-2266,Fax:82-42-860-2789,Email:hmb@kari.
re.
krGi-WookNamKoreaAerospaceResearchInstitutePhone:82-42-860-2365,Fax:82-42-860-2789,Email:gwnam@kari.
re.
krABSTRACTRecently,manyairportsworldwidehaveinstalledtheGBASgroundstationsandbeenpursuingCategory-Iprecisionapproachservices,GAST(GBASApproachServiceType)-C,basedontheminthenearfuture.
ThenextgoalofGBASisprovidingtheCAT-II/IIIlevelprecisionapproachservice,whichiscalledGAST-D.
SincetheGAST-CandDuseravionicsutilizeonlyL1signal,theyshouldmitigatetheanomalousionosphericgradientsproperlytoprotecttheuserintegrity.
SinceGAST-Cavionicsdonottakeanyresponsibilityonintegritymonitoringincludingionosphereanomalydetection,thegroundstationsshouldconsideralltheworstcaseconditionsofionospherethreatswhichmadetheuserprotectionlevelsbecometooconservative.
Ontheotherhand,GAST-Davionicshavebeendecidedtotakechargeofsomeofthemonitors,sothosearerequiredtoperformvariousmonitoralgorithmstoexcludemeasurementsunderthreat:airborneCCD(CodeCarrierDivergence)monitor,dualsmoothingionogradientmonitoralgorithm,geometryscreeningandsoon.
TheairborneCCDamongthemonitorsisemployedtodetectandexcludetherangemeasurementsaffectedbythelargestationaryionospheregradients,sothedetectionperformanceofthemonitorimpactsonthesystemavailability.
TheairborneCCDmonitoralgorithmisdefinedasaseriesoftwolineartimeinvariantfilterswithatimeconstantof100secondsandasampleintervalbyRTCADO-253C.
Therefore,themonitorperformanceisexpectedtobedependentontheconstants,whichhasbeenhardlyresearchedbefore.
Thelongtimeconstantofthefilterreducesthemultipathandnoisecontributionofthepseudorangemeasurementsbutleadsslowresponsetothedivergencechange.
Theauthors'previousresearchshowedthattheshorttimeconstantscouldimprovethedivergencedetectionperformanceundermultipathlimitedenvironments.
Andthedifferentsampleintervalscancausedifferentfilterinputs,whichisthedifferencebetweenthecodeminuscarriermeasurementsinsuccessiveepochs.
Thefilterinputswithshortersampleintervalshavelessmultipathinducederrorssincethemultipatherrorsarehighlycorrelatedinashorttimeperiod,whichleadslowerdetectionthresholds.
Ontheotherhand,thoseinputshaveonlyasmallfractionoftheionosphereinduceddivergencerate,sotheoutputscouldnotrevealthedivergenceeffectsclearlyoutofthenoiseerrors.
Forthesereasons,thepaperinvestigatestheperformancesensitivityoftheairborneCCDmonitorswithdifferenttimeconstantsandsampleintervalswithaconsiderationoftheairbornemultipathcharacteristicsandthemagnitudeofthecodecarrierdivergencerate.
Fortheinvestigation,thepaperanalyzestheresponseoftheairborneCCDmonitorswithdifferentconstantswithregardstothemultipathandthedivergencecharacteristicstheoretically.
Andthesimulateddatawithvariousmultipathconditionsareprocessedtoshowtheperformancesensitivity.
Basedontheresults,thepapersuggeststheoptimaltimeconstantandsampleintervalconfigurationsoftheairborneCCDmonitorunderdifferentenvironmentstoobtainhigherdetectionperformancethanthelegacyone.
KEYWORDS:GBAS;GAST-D;CodeCarrierDivergence;Sensitivity;AirborneSession12AEmbracingtheMulti-GNSSEra1540-1700InvitedSpeakerSessionTheMulti-GNSSExperimentoftheInternationalGNSSServiceOliverMontenbruckDLR,GermanSpaceOperationsCenter,GermanyPhone+49(8153)28-1195,fax-1450,oliver.
montenbruck@dlr.
deChrisRizosUniversityofNewSouthWales,Australiac.
rizos@unsw.
edu.
auUrsHugentoblerTechnischeUniversittMünchen,Germanyurs.
hugentobler@bv.
tu-muenchen.
deABSTRACTTheInternationalGNSSService(IGS)has,overmanyyears,setthegoldstandardforhigh-precisionGPSandGLONASSmeasurementmodelingandanalysis.
Topavethewayforafutureprovisionofhigh-qualitydataandproductsforallconstellations,theIGShasinitiatedtheMulti-GNSSExperiment(MGEX–http://igs.
org/mgex).
Itservesasaframeworkforincreasingtheoverallawarenessofmulti-GNSSwithinthescientificandengineeringcommunities,aswellastofamiliarizeIGSparticipantsanduserswiththenewnavigationsystems.
ThepresentationdescribestheMGEXmulti-GNSSnetwork,whichhasbynowgrowntomorethan70stationsaroundtheglobeandprovidesfreeaccesstonewconstellationsandsignalsforallinterestedusers.
MostoftheMGEXstationsalsoprovidereal-timeobservationsandthusassisttheearlyincorporationofallconstellationsintoreal-timeIGSservices.
FirstproductsderivedfromtheMGEXnetworkincludeGalileo-IOVandQZSSorbitandclockdataaswellascumulativemulti-GNSSbroadcastephemerides.
Thequalityoftheseproductsispresentedandplansfornewproductsarehighlighted.
KEYWORDS:GNSS,IGS,MGEX,Network,real-time,ephemerisproductsWhataretheIssueswithMulti-GNSSEnablingtheNationalPositioningInfrastructureDrJohnDawson,GeoscienceAustralia,Canberra,AustraliaAbstractnotProvidedMulti-GNSSandtheResearchAgendaProfessorPeterTeunissen,CurtinUniversity,Perth,AUSTRALIAAbstractnotProvidedSession12CIonosphere1540-1700IonosphericPathDelayModellingforSpacecraftFormationFlyingYangYang(1)NorthwesternPolytechnicalUniversity;SchoolofSurveying&GeospatialEngineering/UniversityofNewSouthWales/Australia+61416980313&yiyinfeixiong@gmail.
comYongLi(2),AndrewG.
Dempster(3)SchoolofSurveying&GeospatialEngineering/UniversityofNewSouthWales/Australia+61293854173&yong.
li@unsw.
edu.
au,a.
dempster@unsw.
edu.
auABSTRACTApartfromabsoluteorbitdeterminationinformation,manycurrentandfuturespacemissionsrequirerelativenavigationsolutionstobeavailableonboardthespacecraft.
GNSSisidealtomeetwithsuchrequirementsbecauseofitslong-termstableaccuracyandglobalavailability.
ItiswellknownthatofthevariouserrorsourcesintheGNSSobservables,theionosphericpathdelayisoneofthelargest.
EventhoughcommonmodeGNSSerrorscanbemitigatedtoalargeextentbydouble-differencingobservables,residualeffectsduetoionosphericdelaymaystillbesignificantwhenspacecraftseparationislarge.
Henceaccuratemodellingofionosphericdelayswillimproverelativenavigationaccuracy.
Thispaperdescribesamethodtosolvethezero-differencedionosphericdelaymakinguseofdual-frequencymeasurements.
Thenthedouble-differencedionosphericdelayerrorscanbedetermined,andsubsequentlyeliminatedfromtheobservables.
AnewpseudorangemeasurementwasfirstformedbydifferencingtheL1andL2measurements,whichwerealsosmoothedusingthecarrierphasemeasurements.
Inthismeasurementequation,theionosphereerrorwastransformedintoafunctionoftheverticaltotalelectroncontent(VTEC),usingthemodifiedLearmappingfunction.
Thenthedifferentialcodebiases(DCBs)ofalltheGNSSsatellitesandthereceiverswereestimatedbyaleastsquaresmethodonthebasisthattheVTECwasmodelledusingthesphericalharmonicfunction.
OncetheDCBswereobtainedusingalongGNSSobservationarc(forinstance1hourofdata),theyweresubstitutedintothenewobservableequationtocalculatetheionosphericdelay.
AsetofGravityRecoveryandClimateExperiment(GRACE)flightdatawereusedtotesttheproposedmethod.
TheestimatesoftheDCBsandionosphericpathdelaywillbepresented.
KEYWORDS:relativenavigation,modifiedLearmodel,differentialcodebiases,ionosphericpathdelayIonosphereDataAssimilationCapabilitiesforRepresentingtheHigh-LatitudeGeomagneticStormEventinSeptember2011DmitrySolomentsev(1)CentralAerologicalObservatory/Dolgoprudny,RussiaPhone/Fax:+74954086221,e-mail:d.
solomentsev@gmail.
comKnutStanleyJacobsen(2)NorwegianMappingAuthority/Hnefoss,NorwayPhone:+4732118381,e-mail:knut.
stanley.
jacobsen@kartverket.
noBorisKhattatov(3)FusionNumericsLLC,Boulder,Colorado,USAPhone:+1-720-938-2184,e-mail:boris@fusionnumerics.
comAntonTitov(4)CentralAerologicalObservatory/Dolgoprudny,RussiaPhone/Fax:+74954086221,email:anton@ionosphere.
ruABSTRACTSeveregeomagneticstormshavestrongimpactonspacecommunicationandsatellitenavigationsystems.
Forecastingappearanceofgeomagneticallyinduceddisturbancesintheionosphereisoneoftheurgentgoalsofthespaceweathercommunity.
Thechallengeisthattheprocesses,governingthedistributionofthecrucialionosphericparametersarepoorlyknownandthemodels,builtusingtheempiricalparameterizationshavelimitedcapabilitiesforoperationalpurposes.
Ontheotherhand,dataassimilationtechniquesarebecomingmoreandmorepopularfornowcastingthestateofthelarge-scalegeophysicalsystems.
Wepresentanexampleoftheionosphericdataassimilationsystemperformanceassessmentduringastronggeomagneticevent,whichtookplaceon26September2011.
Thefirst-principlemodelhasassimilatedslantTotalElectronContentmeasurementsfromadensenetworkofgroundstations,providedbytheNorwegianMappingAuthority.
Theresultshaveshownrathersatisfactoryagreementwithindependentdata(e.
g.
Tromsoionosondemeasurements)anddemonstratethattheassimilationmodelcanbeusedforoperationalpurposesinhigh-latituderegions.
Theoperationalsystemperformanceassessmentisthesubjectoffuturework.
KEYWORDS:ionosphere,geomagneticstorm,dataassimilationmodel,spaceweathernowcastingComparingGPSRadioOccultationObservationswithRadiosondeMeasurementsOverAntarcticaR.
Norman1,J.
LeMarshall1,2,B.
A.
Carter1,K.
Zhang1,G.
Kirchengast3,S.
Alexander4,C-S.
Wang1andY.
Li11SatellitePositioningforAtmosphere,ClimateandEnvironment(SPACE)ResearchCentre,RMITUniversity,Melbourne,Australia,Tel:99256735,email:robert.
norman@rmit.
edu.
au2CentreforAustralianWeatherandClimateResearch(CAWCR),BureauofMeteorology,Melbourne,Australia3WegenerCenterforClimateandGlobalChange(WEGC),UniversityofGraz,Graz,Austria4AustralianAntarcticDivision,Hobart,Tasmania,AustraliaABSTRACTGPSRadioOccultation(RO)isaspace-basedtechniqueforsoundingtheEarth'satmosphere.
ThistechniquehasbeenshowntosignificantlyimproveweatherforecastingandclimatemonitoringovermanyregionsoftheEarth.
TheGPSROtechniqueusesspecially-designedGPSL-bandfrequencyreceiverson-boardLowEarthOrbit(LEO)satellitestoreceivesignalsfromGPSsatellites.
TheConstellationObservingSystemforMeteorology,IonosphereandClimate(COSMIC)isajointTaiwanandUSAsatelliteprogramandwaslaunchedintoorbitinApril2006.
GPSROdatafromthisconstellationofsixFORMOSAT-3(FormosaSatelliteMission#3),LEO(800kmaltitude)micro-satellitesprovidesanobservationaldatatypeforoperationalmeteorologyandsignificantinformationonthethermodynamicstateoftheatmosphere.
IntheAntarcticregionthereareonly18radiosonde(RS)weatherstationsmainlydistributedalongthecoastalfringe.
AssuchthisRSnetworkisfarfromidealforstudyingtheatmosphere,meteorologyandclimatologyintheAntarcticregion.
ItdoeshoweverprovideexcellentreferencestationstotestandvalidatetheGPSROtechniqueasasuitablemeteorologicaldatatypeintheAntarcticregion.
InthisstudytheCOSMICGPSROtemperatureandpressureprofilesarecomparedtothosemeasuredusingradiosondesintheAntarcticregion.
Yearlyandseasonally,weightedareaaveragetemperatureprofilesfromtheAntarcticregionarealsopresented.
KEYWORDS:RadioOccultation,Antarctica,radiosonde,satellites,COSMICPosters–Tuesday&WednesdayLunchtimeIonosphericDelayEstimationUsingtheModifiedIDWGridModelJungminJoo(1)SatelliteNavigationTeam/KoreaAerospaceResearchInstitute/SouthKoreaPhone:+82-42-860-2554Fax:+82-42-860-2789Emailaddress:jmjoo@kari.
re.
krMoonbeomHeo(2)SatelliteNavigationTeam/KoreaAerospaceResearchInstitute/SouthKoreaPhone:+82-42-860-2266Fax:+82-42-860-2789Emailaddress:hmb@kari.
re.
krABSTRACTThelargestsourceofpositioningerrorforsingle-frequencyusersoftheGPSistypicallytheradiodelaycausedbytheionosphere.
Uptonow,eventhoughseveralanalyticfunctionbasedmodelsareavailableforionosphericerrorcorrections,gridbasedmodelsarepreferredduetotheirgreaterestimationaccuracyandlesscomplexity.
OneoftheionosphericgridmodelsusedfortheUSWAASistheInverseDistanceWeighted(IDW)modelweightedwithKlobucharionosphericmodel.
Inthispaper,weproposeamodifiedIDWestimationmethodusingadaptivecut-offradiusandoptimaldistanceweightingforthehigh-resolutionionospheregridbasedservice.
Iftargetserviceareaislocalrelatively,smallergridsizeisappropriatetoimprovetheintegrityperformanceofsystemlevel.
OurproposedmethodalsousethelinearcombinationmodelofKlobucharandGalileoNeQuickmodelasanominalionosphericdelaymodelinsteadofKlobucharmodeltoimproveestimationaccuracy.
Inpreviousresearchresults,formiddle-latitudegeographicregion,theNeQuickmodelisofferingbetterbehaviorthantheKlobucharmodelexceptforactiveionosphericactivitystate.
Whenwesimulatedin1x1degreegridresolutionconditionovertheKoreanserviceregion,IPPdensityatanyIGPwas10andlessandIPPdensitiesatotherIGPswereenoughtocomputethedelay.
Whenthenumberofreferencestationsandtheircoordinatearerestricted,properIPPdensitiesatallIGPsisrequiredtomeettheaccuracyandavailabilityperformancerequirementsofsystem.
OurproposedmethodisthefunctionoftheIPPdensityanditsvariationrateandcontrolsthecut-offradiusuntilproperIPPdensityismaintainedandthensetupIPP'soptimaldistanceweightinginthecut-offradius.
Inthevarioussimulationresults,itdemonstratedthattheproposedschemeisabletomeettheexpectedperformanceonthegridmodelwithhighgridresolution.
KEYWORDS:IonosphericDelayEstimation;InverseDistanceWeighted(IDW)Model;NeQuickModel;KlobucharModel;AdaptiveCut-offRadiusTimingPerformanceofV2R3NamuruOperatinginPosition-HoldModeJosephP.
GauthierUniversityofNewSouthWales+61416028286,joseph.
gauthier@student.
unsw.
edu.
auEamonnP.
GlennonUniversityofNewSouthWales+61293137493,e.
glennon@unsw.
edu.
auAndrewG.
DempsterUniversityofNewSouthWales+61293856890,a.
dempster@unsw.
edu.
auABSTRACTOneoftheprimaryoutputsfromGPSreceiversisapulsepersecond(PPS)signalthatisalignedwithGPStime.
Whereasnonstationaryreceiverstypicallyoperatein3Dmode,calculatingaposition-velocity-time(PVT)solutionateachepoch,stationaryreceiverstypicallyhaveaprioriknowledgeoftheirpositionandvelocity,therebyenablingamorespecializedmodeofoperation:position-holdmode.
Inthispaper,thesolutionmethodforposition-holdmodeisderived,andaperformancecomparisonbetweenitand3Dmodeismade.
TheexperimentswereperformedwithanAgilent53230AUniversalFrequencyCounter/TimerandaSpirentGSS6560signalsimulator.
TheresultsshowthattheV2.
3Namuruachievesitsbesttimingperformancewhenoperatinginposition-holdmode;thisagreeswithpriorresearchbyothersondifferentGPSreceivers.
KEYWORDS:GPS,timing,position-hold,PPS,sawtoothModifiedIndoorPositioningMethodUsingWLANRSSIMeasurementsandAPConfigurationInformationJunGyuHwangSchoolofElectronicsEngineering/KyungpookNationalUniversity/KoreaFax:+82-53-950-5505,Phone:+82-53-950-7567,Email:cjstk891015@naver.
comJoonGooParkSchoolofElectronicsEngineering/KyungpookNationalUniversity/KoreaFax:+82-53-950-5505,Phone:+82-53-950-7567,Email:jgpark@knu.
ac.
krABSTRACTResearchesonWLAN(WirelessLocalAreaNetwork)indoorpositioningmethodofmobiledeviceforitscosteffectivenessandhighpositioningaccuracyarehottopicsinnetworkbasedindoorpositioningarea.
GeneralWLANbasedpositioningmethodsarefocusedonestablishingmoreaccuracyrelationshipbetweentruelocationandRSSI(ReceivedSignalStrengthIndication)'sfromAP(AccessPoint)'s.
Inthisprocess,thereisnoenoughconsiderationfortheconfigurationinformationofAP's.
WhenAP'sareconcentratedinacertainareafromtargetmobiledevice,calculatedpositioningerrorusuallyincreases.
Toovercomethisproblem,thispaperproposesanenhancedindoorpositioningmethodbyconsideringtheconfigurationinformationofAP's,additionally.
Forthispurpose,weadoptdilutionofprecision(DOP)forreflectingAPconfigurationselectioncriteria.
ThisproposedmethodselectsanAPcombinationusingDOPinformationandcalculatesthepositionoftargetmobiledeviceusingtheRSSIinformationfromtheselectedAP's.
Simulationandexperimentalresultsshowthattheproposedmethodcanimprovepositioningaccuracysignificantly.
KEYWORDS:Indoorpositioning,WLAN,RSSI,DilutionofPrecision(DOP).
AnalysisoftheIntegrationofDifferentialGNSSSystem(VRS/RTK)withaSBASSystemPhd.
IsraelQuintanilla(1)DepartmentofCartographicEngineering/TechnicalUniversityofValencia/SpainMobilePhone0034630228230&Fax0034963877559.
email:iquinta@cgf.
upv.
esPhd.
JoseLuisBernéValero(2)DepartmentofCartographicEngineering/TechnicalUniversityofValencia/SpainMobilePhone0034630228230&Fax0034963877559.
email:jlberne@cgf.
upv.
esMr.
JesusOlivares(3)DepartmentofCartographicEngineering/TechnicalUniversityofValencia/SpainMobilePhone0034630228230&Fax0034963877559.
email:jlolivares@cgf.
upv.
esMr.
KevinFranquin(4)DepartmentofCartographicEngineering/TechnicalUniversityofValencia/SpainMobilePhone0034630228230&Fax0034963877559.
email:kevin.
franquin@gmail.
comABSTRACTTheaimofthisarticleistoconductananalysisoftheintegrationofdifferentialGNSSsystem(VRS/RTK)withaSBASsystem(morespecificallytheEuropeanairnavigationsystemEGNOS).
Todoso,apracticalanalysisstudyofthosedifferentsystemsandonthecorrespondingairstandardwillbecarriedout.
Thenpracticaltestswillbeexecutedtocomparetheprecisionandcontinuityoftheabovesystems,SBASGNSSreceiversonboardhelicopter.
Tothisendtherehavebeenfourtrials;twoonthegroundtocheckthecorrectoperationofthereceivers,andtwowithhelicopters,onetotesttheaccuracyVRS/RTK/EGNOS,andtheothertostudytheintegrationEGNOS/VRS/RTKwithILSfromthehelicopter.
WewillshowtheanalysistocomparetheaccuracyandcontinuitybetweenSBASsystemanddifferentialGNSSandproposeasystemcomplementtoimprovethelandingsystem.
KEYWORDS:SBAS,RTK,VRS,EGNOS,Navigation.
PrecipitableWaterVapourEstimationusingObservationsfromtheAustralianRegionalGNSSNetworkforClimateMonitoringSuelynnChoySchoolofMathematicalandGeospatialSciences,RMITUniversity,AustraliaPhone:+61399252650Fax:+61396632517Email:suelynn.
choy@rmit.
edu.
auJohnDawsonNationalGeospatialReferenceSystems,EarthMonitoringandHazardGroup,GeoscienceAustralia,AustraliaPhone:+61262499028Fax:+61262499999Email:John.
Dawson@ga.
gov.
auMinghaiJiaNationalGeospatialReferenceSystems,EarthMonitoringandHazardGroup,GeoscienceAustralia,AustraliaPhone:+61262499045Fax:+61262499999Email:Minghai.
Jia@ga.
gov.
auYuriyKuleshovNationalClimateCentre,BureauofMeteorology,AustraliaPhone:+61396694896Email:Y.
Kuleshov@bom.
gov.
auABSTRACTAtmosphericwatervapourisacriticalcomponentofthegreenhouseeffectandplaysasignificantroleintheglobalclimatesystem.
Theknowledgeofthelong-termspatialandtemporalvariabilityofwatervapourisvitalforunderstandingclimatechange.
TheGlobalPositioningSystem(GPS)haslongofferedtheprospectofretrievingcolumnintegratedPrecipitableWaterVapour(PWV)profilesfromthetime-varyingtroposphericZenithPathDelay(ZPD),whichcanberetrievedbystochasticfilteringoftheGPSmeasurements.
However,observingGPS-PWVforclimatestudiesrequiresahomogenousandlong-termtimeseriesofGPSdata.
WepresentaregionalreanalysisofGPSdatafocussingontheAustralianRegionalGPS/GNSSNetworkstationsfrom1997to2012(15years).
ThesestationsareselectivelychosentoprovidearepresentativeregionaldistributionofGPSsitesontheAustraliancontinentwhileensuringconventionalmeteorologicalobservations(surface-baseddata)areavailableforPWVconversionandotherPWVsensors(e.
g.
upper-airdatafromradiosondes)forvalidationpurposes.
Theresearchworkisdividedintothreecomponents:1)estimationofhomogenouslong-termtroposphericZPDfromGPSmeasurementsthatareaccurate,stableandconsistent;2)conversionoftroposphericZPDtoPWVestimatesgivensurfacetemperatureandpressurereadings,and3)intertechniquecomparisonandvalidationoftheGPS-derivedPWV.
ThederiveddatawillbeusedtoinvestigatetheseculartrendandseasonalvariationPWVtimeseriesanditsimplicationsforclimateapplication.
ThisresearchrepresentsthefirstattempttoutilisetheAustralianregionalnetworkofGPSstationstostudytheclimateprocessesandvariationsfromthelong-termtimeseriesofGPS-PWV.
KEYWORDS:GPS,PWV,ARGN,Climate.