简介:Thispaperpresentsanewsplinecalledarcspline.Ittakestwoarcsconnectingadjacentpointsamongasampledseries,withknowntangentalofeachsampledpoint.Thecalculationfortheparallel.thecurvelengthandthesegment-ingpointcoordinatesaresimple,thusmakingmapsymbolgenerationsimplified.When'arclet'occurs,somespecialprocessingmustbetaken.
简介:随着科学技术的不断进步,GIS技术和计算机辅助地图制图技术在社会各领域的应用越来越广泛,GIS数据和电子地图数据的社会需求爆炸性增长,各具特点的GIS和制图应用软件如雨后春笋般涌现。这些软件的支持平台、语言环境都有所不同,但各有各的优点,其中的一个共同特点是可以实现数据转换。作业人员可以合理利用一个软件的特点,去弥补其他软件的不足,以提高制图的质量和增加作业的手段。Arc/Info是美国环境系统研究所(ESRI)的代表产品,在当前众多的地理信息系统软件中,影响广、功能强、市场占有率高。笔者在生产实践过程中应用了部分国内常用的GIS和地图制图软件系统,下面介绍关于Arc/Info与AutoCAD、MapGIS、MicroStation之间数据转换的一些方法。
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.
简介:目前,闪电是10自然灾难之一,并且它也是力量打断的最高的环境因素。它经常引起巨大的损失到电的系统。自从1980年代末,中国和科技的Huazhong大学的州的格子公司的武汉高电压研究所一直在研究并且发展中闪电地点系统(LLS)。在mid-1990s,一个闪电察觉网络在中国在29个省和城市被创造。很快发现闪电事故首先被使用,还原剂它极大地驱动打断。另外,它保证高效率和电系统的安全操作。显著利益被完成。中国的LLS通过了一“放的取向-放的时差-综合的放”开发过程。放的精确,察觉效率,自动化的学位,有实行可能和应用范围被改进。另外,国家网络的一个闪电信息系统计划被实现了,它满足整个协会。
简介:Coastallowlandshavelargeareasofhazardimpactandrelativelylowcapacityofpreventiontothewaterrelatedhazards,whichhavebeenindicatedbythewide-spreadfloodhazards,highpercentagesoflandwithhighfloodvulnerability.Increasingpopulationpressureandtheshiftofresourcesexploitationfromlandtoseawillforcemoreandmorecoastallowlandstobedevelopedinthefuture,furtherenhancingthedangerofwater-relatedhazards.Inthispaper,thecoastallowlandsinthenorthernJiangsuprovince,China,wereselectedasacasestudy.TheInterpretationStructuralModel(ISM)wasemployedtoanalyzethedirectandindirectimpactsamongtheelementswithinthesystem,andthereby,toidentifythecausalelements,middlelinkages,theirexpressions,andrelations.