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:二维地理信息系统远远不能满足人们的要求,取而代之的是建立空间的立体的三维GIS。不规则四面体被认为是最简单的数据表示方法之一,本文就三维Delaunay剖分及其在GIS中的应用作了阐述。
简介:从GIS技术发展的趋势来看,三维GIS是当今GIS领域的前沿技术,它与可视化、虚拟现实的集成已经成为了GIS研究的重要领域。提出了一种基于3dsmax提供的程序开发语言MAXScript在GIS的三雏可视化中开发技术。
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。