地信专业英语

1ProfessionalEnglishforGeographicalInformationSystem2PartⅠTheBasicConceptofGIS•1.WhatisGIS?(L.1)•2.WhatkindsoffunctionsdoesaGIShave?(L.2)3PartⅠ——1.WhatisGIS?Geographic(/,dʒi:ə'ɡræfik/)informationsystem——UnitedStatesGeographical(/,dʒi:ə'ɡræfikl/)informationsystem——EuropeanGeomatique(地理信息技术)——Canada4PeopleHardwareSoftwareDataMethodsGISFigureComponentsofGIS5PartⅠ——1.WhatisGIS?TheGIShasfoursubsystems:1）Adatainputsubsystemthatcollectsandpreprocessesspatialdatafromvarioussources.2）Adatastorageandretrieval(/ri’tri:vəl/)subsystemthatorganizesthespatialdatainamannerthatallowsretrieval,updating,andediting.6PartⅠ——1.WhatisGIS?TheGIShasfoursubsystems:1）Adatainputsubsystem2）Adatastorageandretrievalsubsystem3）Adatamanipulation(/mə,nipju’leʃən/)andanalysissubsystemthatperformstasksonthedata,aggregates(合并/’æɡriɡit/)anddisaggregates,estimatesparametersandconstraints(约束条件/kən’streint/),andperformsmodelingfunctions(函数).4）Areportingsubsystemthatdisplaysallorpartofthedatabaseintabular,graphic,ormapform.7PartⅠ——2.WhatkindsoffunctionsdoesaGIShave?1）DatainputsubsystemInput:“encoded”(points,lines,areas)intothecomputerfromacollectedsource.Sources:Aerial(/’ɛriəl/)photography——航空照片，航空摄影Digitalremotesensing——数字遥感Surveying——测量Digitallinegraph(/ɡræf/)(DLG)——数字线划地图(矢量)Digitalelevation(/٫elə’veiʃən/)models(DEM)——数字高程模型Digitalorthophoto/‘ɔ:θəu/map(DOM)——数字正射影像Visualdescriptions——视觉描述Statisticaldata——统计数据8PartⅠ——2.WhatkindsoffunctionsdoesaGIShave?2）DatastorageandretrievalsubsystemPoints,lines,areasarestoredasgridcellsorcoordinate(/kəu'ɔ:dineit/)pairsandpointersincomputer.Attributetablesareassociatedwithcoordinatepairs.Retrievalrequiresefficientcomputersearchtechniques.9PartⅠ——2.WhatkindsoffunctionsdoesaGIShave?3）Datamanipulationandanalysissubsystem——theheartoftheGISUsesthepowerofthecomputertomeasure,compare,anddescribecontentsofthedatabase.Allowsreadyaccesstotherawdataandallowsaggregationandreclassificationforfurtheranalysis.10PartⅠ——2.WhatkindsoffunctionsdoesaGIShave?4）ReportingandoutputsubsystemThemapisonlyonetypeofGISoutput.Alsoincludestables,charts(图表),diagrams(曲线图),photographs(照片).11DatasourceRealWorldSpatialDatabaseUserGISsystemCapturingSpatialdataSpatialdataInputSpatialdataManagementDecisionSupportSolveSpatiallyReferencedProblems12PartⅠ——2.WhatkindsoffunctionsdoesaGIShave?LandinformationsystemParcel-basedLISCAD/CAM13PartⅡDataStructureandDatabaseofGIS•1.GISdatamodels(L.6)•2.Digitalelevationmodeling(L.14)14PartⅡ——1.GISdatamodelsGISstoresinformationabouttheworldasacollectionofthematiclayers(专题图层)thatcanbelinkedtogetherbygeography.Thisapproachallowsustoorganizethecomplexityoftheworldintoasimplerepresentationtohelpfacilitate(/fə’siliteit/)ourunderstandingofnaturerelationships.15PartⅡ——1.GISdatamodels1）GISdatatypesThebasicdatatypesinaGISreflectstraditionaldatafoundinamap.Spatialdata:describestheabsolute(/’æbsəlu:t/)andrelativelocationofgeographicfeatures(地理要素).Attributedata:describescharacteristicsofthespatialfeatures(空间要素).16PartⅡ——1.GISdatamodels2）SpatialdatamodelsVector(矢量)Raster(栅格)Image(影像)：Reflectspicturesorphotographsofthelandscape,verysimilartorasterdata,howevertypicallylackstheinternalformats(格式)requiredforanalysisandmodeling(建模)ofthedata.17PartⅡ——1.GISdatamodels3）VectordataformatsVectorstorageimpliestheuseofvectors(directionallines)torepresentageographicfeature.Coverage(数据层,/’kʌvəridʒ/)——Spatialrelationshipmodel,topology(拓扑,/tə’pɔlədʒi/)--ArcinfoShapefile(数据层)——Spatialrelationshipmodel,nontopology(非拓扑)--ArcviewGeodatabase(空间数据库或地理数据库)——Object-basedmodel--ArcGIS18PartⅡ——1.GISdatamodels3）Vectordataformats（mapstructure）Annotation(注记,/,ænəu'teiʃən/):textlabelingArcs(弧段):linesegments(线段)formingpolygonborders(边界)orindividuallinearfeatures(线性要素)Polygons(多边形,/’pɔli:,gɔn/):areasenclosed(闭合)byarcsPoints(点):singlecoordinatepairs.•Nodes(节点):pointsattheendofarcs•Vertices(vertex)(顶点):pointsalonganarc•Discretepoints(离散点):individualpointfeatures,polygoncentersortextpositions•Tics(控制点):registration(配准/٫redʒi’streiʃən/)controlpoints19PartⅡ——1.GISdatamodels4）Rasterdataformats（mapstructure）Rasterdatamodelsincorporate(吸收)theuseofagrid-celldatastructurewherethegeographicareaisdividedintocellsidentifiedbyrow(行)andcolumn(列).Coverage(数据层):setofmapfeaturesAnnotation(注记):textlabelingSurface(表面):continuousgradient(梯度)20PartⅡ——1.GISdatamodels4）Rasterdataformats（mapstructure）Area(地区):setofpartialandwholecellsformingareal(面状)features.Lines(线):setofpartialcellsformingbordersorlinearfeatures.Cells(单元格):singlecolumn,rowposition.Partial(部分):locationswithattributesinjustpartofacell.Whole(全部):locationswithattributesthroughouttheentirecell.Tics(控制点):registration(配准)controlpoints.21PartⅡ——1.GISdatamodels5）ImagedataImagedataistypicallyusedinGISasbackgrounddisplaydataorasagraphic(图形)attribute.Remotesensingsoftwaremakesuseofimagedataforimageclassification(分类)andprocessing(处理).Typically,theimagedatamustbeconverted(转换)intoarasterformat(andperhapsvector)tobeusedanalytically(/,ænə’litikli)withtheGIS.22PartⅡ——1.G