简介:一、前言在城市综合管网GIS数据生产中,由于管线的属性信息、空间信息数据量大,利用桌面数据库管理难度很大,数据质量很难得到保障,且不利于大规模生产的需要。经过多方论证:在Delphi平台下利用ActiveX自动化技术开发的客户/服务器(c/s)数据库应用程序,其中ADO技术、OLE技术、ActiveXAutomation技术等这些软件开发的尖端技术的应用,使该系统具备数据处理能力大大增强。选用MicrosoftSQLServer2000作为数据库平台,不仅使该系统能管理海量数据,支持更多的客户端,而且成为大规模的管线生产后台数据库。大量数据字典的采用是在没有统一的管线代码的情况下,建立自己的一套管线生产代码标准,不仅提高了作业效率,保证管线属性的完整性、规范性,更好地满足客户多元化需求,适应各种GIS环境。系统为MapGISSYNPIP(城市综合管网信息管理系统)提供了良好的接口,更方便数据入库,这样对于利用SYNPIP中小城市来说,利用该系统可以进行管线生产及后期系统维护,使管线数据生产及维护更快捷。
简介:Ageographicinformationsystem(GIS)isahardware/softwaretoolwhichisveryeffectiveincollecting,storing,searching,handling,andvisualizinggeographicdatatogetherwiththeirdescriptiveattributes.Suchatoolisveryhelpfultoapproachawiderangeofsituations,includingmanylogisticproblems.ENEA,astheagencyhavingthetaskofimplementingtheItalianAntarcticProgram(PNRA),hasdecidedtouseaGIS,inordertoincreasetheefficiencyinmanagingthehugeamountofdatacollectedinthecourseofItalianactivityinAntarctica,whichcountsfifteenexpeditionsuptonow.
简介:阐述了传统GIS系统的不足及IntranetGIS系统的特点与组成内容,介绍了IntranetGIS系统建造时应注意的问题,同时提出了解决思路。
简介:Inordertosetupaconceptualdatamodelthatreflectstherealworldasaccuratelyaspossible,thispaperfirstlyreviewsandanalyzesthedisadvantagesofpreviousconceptualdatamodelsusedbytraditionalGISinsimulatinggeographicspace,givesanewexplanationtogeographicspaceandanalyzesitsvariousessentialcharacteristics.Finally,thispaperproposesseveraldetailedkeypointsfordesigninganewtypeofGISdatamodelandgivesasimpleholisticGISdatamodel.
简介:ThedevelopmentofInternetprovidesconvenientenvironmentforinformationsearchingandbrowsing.Italsoofferssanewplatformforgeographicinformationprocessingandanalysis.ThispaperdiscussesorganizationandprocessingapproachtoInternetgeographicinformation,andprovidesanewmethodtocross-platformanddistributedgeographicinformationanditssoftwareimplementation.Theexampieisusedtoshowthepracticalityandsuperiorityofthismethod
简介:ThisworkhasoriginallybeendoneintheP.R.China(WuhanTechnicalUniversityofSurveyingandMapping)andinHongKong(ChineseUniversityofHongKong).Prof.LinHuigaveusefuladvice.Mr.HanHaiyang,andMs.ChenLilihelpedworkwiththeimplementationofprototypesystem.WealsothanktheSwissNationalScienceFoundationforitsfinancialsupportandacknowledgethecommentsofDr.AndreasGeppertandProf.KlausR.Dittrichonanearlierversionofthispaper.
简介:当错误当模特儿在GIS描述曲线的错误,曲线的一个随机的错误过程被建议。以随机的进程,有关曲线的本地错误的四个特征也就是,意味着错误的错误功能,标准错误函数,绝对误差函数,和相关函数,被提出。一条曲线的全部的错误被随机的错误过程的吝啬的方形的积分表示。概率的意思和上面提及的特征的几何意思也被讨论。一个scandigitization实验被设计检查模型的效率。在实验,一条等高线被数字化因为超过100次和大量样品功能从实验被导出。最后,所有错误特征根据样品功能被估计。实验结果证明在数字化的地图数据的系统的错误不是可以忽略的,并且曲线上的点的错误主要依赖于弯曲和曲线的凹度。
简介:ThispaperfirstbrieflylooksbackonthehistoryofcensusGISaroundtheworld,andthensummarizessomepreponderancesofdevelopingurbancensusGISinChina.Andthenathree-tierconstructionarchitecturefortheurbancensusGISisproposed.Finally,usingtheillustrationofthecensusdataofGuangzhoucity,thepaperanalyzesandelaboratessomeissuesontheurbancensusGISdesigning,suchasdatamanagement,datawarehousebuilding,anddataanalysis.
简介:ThecurrentGIScanonlydealwith2-Dor2.5-Dinformationontheearthsurface.Anew3-Ddatastructureanddatamodelneedtobedesignedforthe3-DGIS.Thispaperanalyzesdiverse3-Dspatialphenomenafromminetogeologyandtheircomplicatedrelations,andproposesseveralnewkindsofspatialobjectsincludingcross-section,columnbodyanddigitalsurfacemodeltorepresentsomespecialspatialphenomenaliketunnelsandirregularsurfacesofanorebody.Anintegrateddatastructureincludingvector,rasterandobject-orienteddatamodelsisusedtorepresentvarious3-Dspatialobjectsandtheirrelations.Theintegrateddatastructureandobject-orienteddatamodelcanbeusedasbasestodesignandrealizea3-Dgeographicinformationsystem.
简介:ManyInternet-GIShavebeenimplementedonthewebandtheyareincreasinglybecominganimportantpartofmultimediacartographythathasmuchmoreusersascomparedtotraditionalGISproductionmedia.InternetGIStechnologyhasprovidedtheGISdynamicinformationacquisitionwithtechnicalsupport.Also,thevisualizationtechnologyofelectronicmaphasprovidedtoolsforGISsymbolswithdynamiccharacteristics.OnthebasisofGISdynamicinformationacquisition,thedesignideaandimplementationmethodsofdynamicsymbolsindynamicGISarepresentedinthisarticle.
简介:Adoptingaprincipleof“check-acceptforthefirstrank,inspectionforthesecondrank”,thispaperbrieflydiscussestherationaleofthesamplinginspectionandthesamplinginspectionschemestodigitalproductsinGIS.TheOCcurveisdrawntoexplainthedeficiencyofthepercentsamplinginspection.Meanwhile,themethodofOneTimeLimitingQualityofcountselectionispresentedastheinspectionschemeforproductiondepartmentswhilethemethodofOneTimeAfter-inspectionMeanPercentDefectiveUpperLimitofcountselectionisforacceptancedepartments.
简介:Ithasbeendebatedthatwhichofrasterandvectoristhemosteffective,fromtheviewpointsofstorageefficiency,processingefficiency,andabilitytocapturetheessenceofgeographicspaceforanapplication.Theremaybenoclearanswertothisdebate.Itseemsappropriatetonotethatthemaindifferencebetweenthemrelatestothedegreetowhichthespatialentitiesofinterestareexplicitinthedata. Ingeneral,rasterremotesensingimageallowstheinvestigatortomeasureandmonitorsurfaceelectromagneticwavevariationinwhichmostobjectsandthespatialinterrelationshipsbetweenthemareimplicit.Inpractice,therearemanypoorlyunderstoodtradeoffsincouplingremotesensingdatatoexistingthematicmaps.Mapsusepointsandlinestorepresentselectedfeaturesoftheenvironmentinageneralizedfashion,buttheobjectssuchasindividualpolygons,linesandpointswithinanimagearetypicallyunknown. TheintegrationofremotesensinginformationintoaGISoccursnaturallyinarasterGISbecausebothdatastructuresareapproximatelythesame.Integrationintoavectorsystemrequiressomewhatmoreeffort,butithasbeenrecentlyachievedbyseveralGISandremotesensingvendors.Whenoneisstoringalargeamountofimagedatarelatedtosomeapplicationsintoaspatialdatabasesystem,itisnotpossibletoprocessthedataandtoobtainpolygonalrepresentationsofallobjectsthatwillbeofinteresttousersinadvance.Ontheotherhand,itmightbeofgreatvalueinsuchasystemtohaveavectorrepresentationofcertainimportantobjects.Forthisapplication,oneneedstodesignasystemwithbothrasterandvectorcapabilities,aswellastoolstointerrelatethem.Especially,asinFig.1,weneedtoprocessbothrasterandvectorsimultaneously. Asdescribedabove,whileaspatialinformationsystemmayhaveseveraldatastructures,thesystemcouldbeextendedinseveralwayswhichcorrespondtothefollowingdifferentproperties(seeFig.2): 1)Thestuructureinforma
简介:网络分析作为GIS的重要功能,在电子导航、交通旅游、城市规划以及电力、通讯等各种管网、管线的布局设计中发挥了重要的作用。随着GIS系统集成应用的不断深入,为了满足用户的应用需求,我们通过二次开发的手段,为一些GIS平台定制了网络分析功能。利用经典的Dijkstra算法,结合GIS数据和平台特点,通过简单的程序设计可以实现复杂的网络分析功能。