简介:Thispaperintroducesthemostadvancedformofelectronicchartdisplayandinformationsystems(ECDIS)whichcomplieswiththePerformanceStandardsforECDISestablishedbytheInternationalMaritimeOrganization(IMO)andtheInternationalHydrographicOrganization(IHO).ItalsodescribesthekeyfeaturesandtheimportantfunctionsofECDIS.ThenthefuturedevelopmentofECDISinmarineisdiscussed.
简介:ThispaperdiscussestheurbanlandgradingsystembasedontheselfdevelopedGISsoftware.Thesystemestablishesthesystemtemplate,therelevantdatastructureandtheempiricalformulasoftheaffectingfactorandeconomicdataoflanduse.Besides,thesystemcancalculatetheserviceradius,sumandlandgradeautomatically.Furthermore,itcandostatisticsandqueryonvariouslandinformationandshowtheresultoflandgradingwithspatialandattributedata.ThispaperillustratestheresultbygivinganexampleofthecommerciallandgradingoftheurbanareaofWuhanCitybytheurbanlandgradingsystem.
简介:Thispaperdescribesthestructure,geometricmodelandgeometriccalibrationofPhotogrammetronI-thefirsttypeofphotogrammetronwhichisdesignedtobeacoherentstereophotogrammetricsysteminwhichtwocamerasaremountedonaphysicalbasebutdrivenbyanintelligentagentarchitecture.Thesystemcalibrationisdividedintotwoparts:thein-labcalibrationdeterminesthefixedparametersinadvanceofsystemoperation,andthein-situcalibrationkeepstrackingthefreeparametersinreal-timeduringthesystemoperation.Inavideosurveillanceset-up,preparedcontrolpointsaretrackedinstereoimagesequences,sothatthefreeparametersofthesystemcanbecontinuouslyupdatedthroughiterativebundleadjustmentandKalmanfiltering.
简介:GeographicalInformationSystem(GIS)iswidelyusedinmanyfields.Withtherapiddevelopmentofcomputernetwork,GISuserscaremoreaboutdatasharinginnetworks.Intraditionalrelationaldatabase,dataconsistencywascontrolledbyconsistencycontrolmechanismwhenadataobjectislockedinasharingmode,othertransactionscanonlyreadit,butcannotupdateit.Thisisappropriateintraditionalrelationaldatabasesthatstoreattributedataandmainlydealwithshorttransactions.Inspatialdatabases,becauseofvastamountofdataandcomplextopologicalrelations,longtransactionaremetfrequently.Ifthetraditionalconsistencycontrolmethodhasbeenusedyet,thesystem'sconcurrencywillbebadlyinfluenced.SotherecomemanynewrequirementsfortheconsistencycontrolinthefieldofGIS.Therearemanyaspectsofdataconsistencyproblemsinspatial databases,suchastheinconsistencybetweenattributeandgeometrydata;theinconsistencyoftopologicalrelationsaftergeometryobjectshasbeenmodified.Inthispaper,othertwocasesofdataconsistencyarediscussedinMulti_userGeographicalInformationSystem. InGIS,therearemanyformsofdata,suchasgeometrydata,attribute,imagedata,andDEMdata.Inthispaper,weonlydiscussspatialgeometrydata.
简介:Onthebasisofpreviouswork,thispaperdesignsanintelligentagentbasedonvirtualgeographicenvironment(VGE)systemthatischaracterizedbyhugedata,rapidcomputation,multi-user,multi-threadandintelligenceandissueschallengestotraditionalGISmodelsandalgorithms.Thenewadvancesinsoftwareandhardwaretechnologylayareliablebasisforsystemdesign,developmentandapplication.
简介:AtpresentE-commercesystemtendstobecomemorecomplex,andtraditionalsystemdesigningmethodscannotfufiltheneedofE-commercesystem,thusrequiringaneffectivemethodassolution.Withthisconcern,thispaperintroducessomeconceptsofcomponenttechnology,thenbringsforwardthenewconnotationandbasicfeaturesofcomponenttechnologythroughtheanalysisofitstechnologicalcharacter.ThispaperfinallydiscussestheapplicationofcomponenttechnologytoE-commercesystem.
简介:[1]NyergesTL.Cognitiveaspectsofhuman-computerinteractionforgeographicinformationsystems.KluwerAcademicPublishers,1995.287~310[2]ChurcherN,ChurcherC.GroupARC——acollaborativeapproachtoGIS.In:Proceedingsofthe8thColloquiumoftheSpatialInformationResearchCentre.UniversityofOtago,1996.156~163[3]ObermeyerNJ,PintoJK.Theroleofgeographicinformationwithinanorganization'sMIS.In:ManagingGISs.TheGuilfordPress,1994.35~51[4]SpencerB.Spatialdatawarehousing.In:ProceedingsofGISAM/FMASLA'97&Geoinformatics'97onMappingtheFutureofAsia-Pacific.China:Taipei.1997.545~553[5]ChenJ,JiangJ,YanR,etal.Integratingandmanagingheterogeneousgeographicinformationforurbanplanning&landadministration.ActaGeodaeticaetCartographicaSinica,1998,27(2):153~160[6]WuR.Towardsanenterprise-wideGISsystem:acasestudy.In:ProceedingsofGISAM/FMASIA'97&Geoinformatics'97onMappingtheFutureofAsia-Pa-cific.China:Taipei,1997.657~671[7]ChenJ,JiangJ,JinS,etal.designingacollaborativeworksystembyintegratingGISwithOA.JournalofRemoteSensing,1998,2(3):59~64[8]GoodmanJN.Albertalandrelatedinformationsystem-afederateddatabasecasestudy.In:ProceedingsofURISA,1994[9]IgrasE.Aframeworkforqueryprocessinginafederateddatabasesystem:acasestudy.In:ProceedingsofURISA,1994[10]ShethAP.Federateddatabasesystemsformappingdistributed,heterogeneous,andautonomousdatabases.ACMComputingSurveys,1990,22(3):183~235[11]NewtonPW,GippsPG,CrawfordJR.Virtualplanninganddesign:anemegingparadigm.In:Proceedingsof4thinternationalconferenceoncomputersinurbanplanningandurbanmanagement.Australia:Melbourne,1995.27~38[12]BennettWS.Visualizingsoftware—agraphicalnotationforanalysis,design,anddiscussion.NewYork:MarcelDekker,Inc.,1992[13]TeisseireM,PonceletP,Cicchetti
简介:Thispaperpresentsadatafusionmethodindistributedmulti-sensorsystemincludingGPSandINSsensors'dataprocessing.First,aresidualχ2-teststrategywiththecorrespondingalgorithmisdesigned.Thenacoefficientmatricescalculationmethodoftheinformationsharingprincipleisderived.Finally,thefederatedKalmanfilterisusedtocombinetheseindependent,parallel,real-timedata.Apseudolite(PL)simulationexampleisgiven.
简介:ThispaperdevelopsaWebGIS-basedGPSvehiclemonitoringsystemwithtypicalthree-tierapplicationarchitectureofB/Spattern.Itprovidesordinaryregistereduserswithavalidandconvenientmeanstogetaccesstoreal-timeGPSlocationinformationofcertainmovingvehiclesatanyplace,andfurtheroffersapowerfultoolforsuperuserstomanageuserinformationandremotelymonitorthosevehiclesandprovidecorrespondingservicestimelyifnecessary.Thesystemarchitecture,functionmodules,keytechnologiesandapplicationinterfacesaregiven.Finally,thevalidityofoursystemisdemonstratedinpracticalcases.
简介:Real-timekinematicGPSprecisepositioninghasbeenplayinganincreasingroleinbothsurveyingandnavigation.Basedonthecity'sfibreLANnetwork,ShenzhenContinuousOperatingReferenceStations(SZCORS)systemhasbeenestablishedandconsistsofGPSreferencestations,systemcontrolcenter,user'sdatacenter,andreal-timedatacomnetwork.TheSZCORSsystemprovidesusersthereal-timecentimeterpositioningorpost-processingmillimeterpositioning.ThispapermakesdiscussiononthestructureofSZCORSsystem.Someexperimentshavebeenmadetotesttheusablity,andthenthedatahasbeenanalyzed.