简介:Throughanalyzingtheprincipleofdatasharinginthedata-basesystem,thispaperdiscussestheprincipleandmethodforintegratingandsharingGISdatabydataengine,introducesawaytoachievethehighintegrationandsharingofGISdataonthebasisofVCTinVC++,andpro-videsthemethodforunitingVCTintoRDBMSinordertoimplementaspa-tialdatabasewithobject-orienteddatamodel.
简介:IthaslongbeenacknowledgedthatGISdatacanbeusedasauxiliaryinformationtoimproveremotesensingimageclassification.Inpreviousstudies,GISdatawereoftenusedintrainingareaselectionandpostprocessingofclassificationresultoractedasadditionalbands.Generally,itisfulfilledinastatisticalorinteractivemanner,soitisdifficulttousetheauxiliarydataautomaticallyandintelligently. Furthermore,iftheclassifierrequestscertainstatisticalcharacteristics,theadditionalbandmethodcannotbeusedbecausemostauxiliarydatadonotmeettherequirementsofstatisticalcharacteristics.Ontheotherhand,expertsystemtechniqueswereincorporatedinremotesensingimageclassificationtomakeuseofdomainknowledgeandlogicalreasoning.Butbuildinganimageclassificationexpertsystemwasverydifficultbecauseofthe“knowledgeacquisitionbottleneck”. Spatialdataminingandknowledgediscovery(SDMKD),istheextractionofimplicit,interestingspatialornon_spatialpatternsandgeneralcharacteristics.Weproposedatheoreticalandtechnicalframeworkofspatialdataminingandknowledgediscovery(Lietal.,1997).Andspatialdataminingissupposedtobeusedintwoaspects,oneisintelligentanalysisofGISdata,theotheristosupportknowledgedriveninterpretationandanalysisofremotesensingimages.SDMKDprovidesanewwayofknowledgeacquisitionforremotesensingimageclassification.Severalresearchershavedonesomeworkinthisfield.Eklundetal.(1998)extractedknowledgefromTMimagesandgeographicdatainsoilsalinityanalysisusinginductivelearningalgorithmC4.5.Huangetal.(1997)extractedknowledgefromGISdataandSPOTmultispectralimageinwetlandclassificationusingC4.5too.Inthesetwostudies,geographicdatawereconvertedfromvectortorasterformatinwhichthesamplingsizeisequaltoimagepixelsize.Theimplementationofdataminingtechniquesinspatialdatabase,especiallyinductivelearningmethod,andthecombinationo
简介:Inordertosetupaconceptualdatamodelthatreflectstherealworldasaccuratelyaspossible,thispaperfirstlyreviewsandanalyzesthedisadvantagesofpreviousconceptualdatamodelsusedbytraditionalGISinsimulatinggeographicspace,givesanewexplanationtogeographicspaceandanalyzesitsvariousessentialcharacteristics.Finally,thispaperproposesseveraldetailedkeypointsfordesigninganewtypeofGISdatamodelandgivesasimpleholisticGISdatamodel.
简介:Atpresent,thereexisttwomethodsusedtorecoverthebathymetryfromaltimeterdata,i.e.thedeterministicmethodandthestochasticmethod.Inthispaper,theprinciplesofthetwomethodsareintroducedfirst.Thenaccordingtothetheoryofleast-squarecollocation,amodifiedstatisticalmodelforrecoveringbathymetryfromaltimeterdataisproposed.ThenewmodelhasbeenusedforcomputingtheoceandepthintheSouthChinaSeafromaltimeter-derivedgravityanomalies.Finallythepredicteddepthsarecomparedwiththeship-bornedepth.Itshowsthattheyagreewitheachotherverywell.
简介:GPS运动学的搬运人阶段大小能被用来决定七个尺寸状态和一个动的搬运人的三个态度参数,例如一架飞机或一只lowearth轨道太空船,一条天线在上被安装收到GPS信号。自从1994,在动的环境的GPS搬运人阶段大小为点高度为二个维的位置和卤18.1cm获得了卤7.9cm的外部精确性,这在中国从摄影测量学的在空中的GPS测试结果被知道。这份报纸与multireference车站描述在空中的GPS搬运人阶段大小并且讨论怎么评估GPS运动学的数据的信心。
简介:作为南极洲以曾经增加的率正在被收集并且创造的数字数据,为研究的这些数据的实用性,GIS分析并且计划一直在增加。当前没有正式标准让这些数据集相遇,它在从不同来源集成数据引起困难。从科学家和研究人员的反馈是那以便在他们需要存取两个的基本、基本的数据集上执行任何种GIS分析:standardised和综合数据和在本地化的区域(一个数据图书馆)的鈥榬aw鈥?数据(一个数字数据产品)。起来直到现在,没有协调途径或程序获得,或甚至存取基本数据集。南极地理数据集成(AGDI)工程在附近都一起带它,也就是说通过一个数据产品和一个数据图书馆为南极洲便于综合基本GIS数据的可获得性。这篇论文描述AGDI是什么,为什么有它,它的目的是什么,AGDI和各种各样的工程的地位的不同部件上的细节在基本数据集的收集包含了。什么可以发生在AGDI开发和一个未来工作节目身上,简短也构画出。
简介:Onthebasisofananalysisoftheerrorsourcesinmultibeamechosoundingsystem,adataprocessingmethodforcompensatingsystematicerrorsinmultibeamsurveyisproposed.Inordertoimprovetheaccuracyofoverallswath,adatafusiontechniqueusingsinglebeamsurveydataascontrolinformationforsinglebeamandmultibeamechosoundingisthenpresented.Somequestionsinvolvedinsolvingtheadjustmentproblem,suchasitsfeasibilityandthenumericalstability,arediscussedindetail,andatwo-stepadjustmentmethodissuggested.Finally,apracticalsurveydatasetisusedasacasestudytoprovetheefficiencyandreliabilityoftheproposedmethods.
简介:Landresourcesarefacingcrisesofbeingmisused,especiallyforanintersectionareabetweentownandcountry,andlandcontrolhastobeenforced.Thispaperpresentsadevelopmentofdataminingmethodforlandcontrol.Avector-matchmethodfortheprerequisiteofdataminingi.e.,datacleaningisproposed,whichdealswithbothcharacterandnumericdataviavectorizingcharacter-stringandmatchingnumber.Aminimaldecisionalgorithmofroughsetisusedtodiscovertheknowledgehiddeninthedatawarehouse.Inordertomonitorlandusedynamicallyandaccurately,itissuggestedtosetupareal-timelandcontrolsystembasedonGPS,digitalphotogrammetryandonlinedatamining.Finally,themeansisappliedintheintersectionareabetweentownandcountryofWuhancity,andasetofknowledgeaboutlandcontrolisdiscovered.
简介:Theincreasingusageofmultimediaobjects,suchasRSimages,scannedphotographs,videorecordings,textsandvoiceinformation,demandsanefficientmethodtoorganizeenormousinformation(Taylor,1996).Intwoyears,thesatelliteremotesensingindustrywillprovidegeographicinformationsystem(GIS)userswithasignificantnewtooltocreatebase_mapandupdatetheirGISdatabaseswithdetailedinformation.Thistoolwillbemoreandmoreusefulwhenthesatelliteimagerywith1mspatialresolutionisused(Kevin,1996). Hypermediatechniqueisfrequentlyusedtodealwithdifferentmedia,andtoorganizethediverseandinnumerabledataincomputerswithverylimitedCPUspeedandmemory.ThetechniquehasbeendemonstratedtobeanefficientwayforprocessingalargeamountofRSimagedata. Inthispaperwepresentthehypermediadatamodel,whichisbasedonRSimageinGIS.Usingthemodelconcept,wecanhandlealargeamountofRSimagedataefficientlywithverylimitedcomputingpower.Wehavedevelopedthemodelwiththreekindsofnodes:interiornode,physicalnodeandcomplexnodetoorganizetheinfinityimage.
简介:Distribution,interoperability,interactivity,componentarefourmainfeaturesofdistributedGIS.Basedontheprincipleofhypermap,hypermediaanddistributeddatabase,thepapercomesupwithakindofdistributedspatialdatamodelwhichisinaccordancewiththosefeaturesofdistributedGIS.Themodeltakescatalogserviceastheoutlineofspatialinformationglobalization,anddefinesdatastructureofhypermapnodeindifferentlevel.Basedonthemodel,itisfeasibletomanageandprocessdistributedspatialinformation,andintegratemulti_source,heterogeneousspatialdataintoaframework.Traditionally,toretrieveandaccessspatialdataviaInternetisonlybythemeormapname.Withtheconceptofthemodel,itispossibletoretrieve,load,andlinkspatialdatabyvector_basedgraphicsontheInternet.
简介:高压缩比率,高译码性能,和进步数据传播是为WebGIS的向量数据压缩算法的最重要的要求。满足这些要求,我们在场一条新压缩途径。这篇论文由把漂流坐标变换成整数坐标以多尺度的数据的产生开始。在屏幕上的变换的点和原来的点之间的距离在2个象素以内,这被证明,因此,我们的途径对顾客方面上的向量数据的可视化合适。整数坐标被传递给一个整数小浪变压器,并且高周波的系数由变压器生产了被正规哈夫曼代码编码。河数据和道路数据上的试验性的结果表明建议途径的有效性:为河数据的压缩比率罐头活动范围10%和20%为道路数据分别地。我们断定更多的注意需要被付到在包含一些点的弯曲之间的关联。
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:ThecurrentGIScanonlydealwith2-Dor2.5-Dinformationontheearthsurface.Anew3-Ddatastructureanddatamodelneedtobedesignedforthe3-DGIS.Thispaperanalyzesdiverse3-Dspatialphenomenafromminetogeologyandtheircomplicatedrelations,andproposesseveralnewkindsofspatialobjectsincludingcross-section,columnbodyanddigitalsurfacemodeltorepresentsomespecialspatialphenomenaliketunnelsandirregularsurfacesofanorebody.Anintegrateddatastructureincludingvector,rasterandobject-orienteddatamodelsisusedtorepresentvarious3-Dspatialobjectsandtheirrelations.Theintegrateddatastructureandobject-orienteddatamodelcanbeusedasbasestodesignandrealizea3-Dgeographicinformationsystem.
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:Thispaperendeavourstoputthediscussiononerrorsanduncertaintiesingeographicalinformationsystems(GISs)inamoresystematicwaybyexaminingthestrengthandweaknessofdiscreteobjectsandcontinuousfields,thetwodistinctschoolsofspatialdatamodelling.Indoingso,itarguesthatneitherdiscreteobjectsnorcontinuousfieldsaloneprovideobjectiveandcompleterepresentationsofhighlycomplexgeographicalphenomena,thoughtherearegoodreasonsforassertingthatcontinuousfieldsarebettersuitedtomodellingspatialdependence,heterogeneityandfuzzinesssignificantingeographicalrealitythandiscreteobjects.Thus,thereseemstobemeritinadoptinganintegratedmodelincorporatinganalyticalcapabilitiesoffieldsandgeneralizationfunctionsofobjects,forwhichextendedTIN(triangulatedirregularnetwork)modelsalongwiththeirduals(Voronoidiagrams)provideapragmaticalsolution.
简介:Thispaperpresentsadatafusionmethodindistributedmulti-sensorsystemincludingGPSandINSsensors'dataprocessing.First,aresidualχ2-teststrategywiththecorrespondingalgorithmisdesigned.Thenacoefficientmatricescalculationmethodoftheinformationsharingprincipleisderived.Finally,thefederatedKalmanfilterisusedtocombinetheseindependent,parallel,real-timedata.Apseudolite(PL)simulationexampleisgiven.