简介:<正>所谓3S技术即GPS、GIS、RS技术。GPS(全球定位系统)是英文缩写词NAVSTAR/GPS(NAVigationSystemTimeAndRanging/GlobalPositioningSystem)的简称。全称应为“测时测距导航系统/全球定位系统”。GPS是由美国研制,并投入实际应用的最新卫星定位系统。其主要目的是为飞机和船舶导航定位。也可以用于其它多种目的。GPS技术已在航空、航天、航海、军事、地质、石油、勘探、交通、测绘等领域得到广泛的应用。美国于1993年6月26日已将GPS21颗卫星和3颗备用卫星全部发射入轨。
简介:为3D城市建模的OGC标准广泛地在越来越多的应用被使用。它定义详细(到有增加精确性和结构的复杂性的LoD4的LoD0)的五个连续层次,在哪个LoD3包括所有外面的外观和几何细节并且随后要求许多存储空间。新LoD与象窗户,门以及更小的fa一样的LoD3模型和开的目标的外面的壳作为壳模型被介绍?果汁饮料目标被投射到墙上。在这份报纸,用户调查被介绍。这的结果调查壳模型能几乎给用户的表演象LoD3模型的一样的视觉印象。Furthermroe,算法被开发从LoD3提取壳模型模型。实验证明这个壳模型能减少原来的LoD3模型的多达90%存储。因此,一方面,它能为一个LoD3模型被用作一个代用品为小显示上的可视化。在另一方面,它能在CityGML被当作详细(SLoD3)的分段,自从它几乎保留信息的一样的数量,但是要求少得多存储空间。
简介:Airborne3DimagewhichintegratesGPS,attitudemeasurementunit(AMU),scanninglaserrangefinder(SLR)andspectralscannerhasbeendevelopedsuccessfully.ThespectralscannerandSLRusethesameopticalsystemwhichensureslaserpointtomatchpixelseamlessly.Thedistinctiveadvantageof3Dimageisthatitcanproducegeo_referencedimagesandDSM(digitalsurfacemodels)imageswithoutanygroundcontrolpoints(GCPs).ItisnolongernecessarytosurveyGCPsandwithsomesoftwaresthedatacanbeprocessedandproducedigitalsurfacemodels(DSM)andgeo_referencedimagesinquasi_real_time,therefore,theefficiencyof3Dimageis10~100timeshigherthanthatoftraditionalapproaches.Theprocessingprocedureinvolvesdecomposingandcheckingtherawdata,processingGPSdata,calculatingthepositionsoflasersamplepoints,producinggeo_referencedimage,producingDSMandmosaicingstrips. Theprincipleof3Dimageisfirstintroducedinthispaper,andthenwefocusonthefastprocessingtechniqueandalgorithm.Theflighttestsandprocessedresultsshowthattheprocessingtechniqueisfeasibleandcanmeettherequirementofquasi_real_timeapplications.
简介:Severaldifferentstrategiesof3Dmodelingareadoptedfordifferentkindsofmanmadeobjects.Firstly,forthosemanmadeobjectswithregularstructure,if2Dinformationisavailableandelevationinformationcanbeobtainedconveniently,then3Dmodelingofthemcanbeexecuteddirectly.Secondly,forthosemanmadeobjectswithcomplicatedstructurecomparativelyandrelatedstereoimagespaircanbeacquired,inthelightoftopology-based3Dmodelwefinish3Dmodelingofthembyintegratingautomaticandsemi-automaticobjectextraction.Thirdly,forthemostcomplicatedobjectswhosegeometricalinformationcannotbegotfromstereoimagespaircompletely,weturntotopological3DmodelbasedonCAD.
简介:一九九四年·测绘法规·山西省人民代表大会常务委员会公告(1-4)…………山西省测绘管理条例(1-5)……………………………关于《山西省测绘管理条例(草案)》的说明……………王银焕(1-9)…………………………………………关于《山西省测绘管理条例(草案)》修改情况的说明…李树森(1-12)………………………………………关于《山西省测绘管理条例(草案)》(修改稿)修改情况的说明李红星(1-14)………………………………………贯彻《山西省测绘管理条例》,促进山西测绘事业的发展夏志朴(1-16)………………………………………·重点工程测量·关于万家寨引黄工程测量控制网的几点意见…………何万龙(1-19
简介:SegmentationandedgeregulationarestudieddeeplytoextractbuildingsfromDSMdataproducedinthispaper.Buildingsegmentationisthefirststeptoextractbuildings,andanewsegmentationmethod-adaptiveiterativesegmentationconsideringratiomeansquare-isproposedtoextractthecontourofbuildingseffectively.Asub-image(suchas50×50pixels)oftheimageisprocessedinsequence,theaveragegraylevelanditsratiomeansquarearecalculatedfirst,thenthresholdofthesub-imageisselectedbyusingiterativethresholdsegmentation.Thecurrentpixelissegmentedaccordingtothethreshold,theaver-agegraylevelandtheratiomeansquareofthesub-image.Theedgepointsofthebuildingaregroupedaccordingtotheazimuthofneighborpoints,andthentheoptimalazimuthofthepointsthatbelongtothesamegroupcanbecalculatedbyusinglineinterpolation.
简介:依据《中华人民共和国测绘法》、《测绘资格审查认证管理规定》和《(测绘资格证书)分级标准》,经测绘单位申请,各市(地)测绘管理办公室初审(含房产测绘业务范围的申请单位经省建设厅初审),山西省测绘局批准,2003年度全省共38家单位取得《测绘资格证书》、6家单位进行测绘资格等级升级。
简介:Theresearchworkhasbeenseldomdoneaboutcloverleafjunctionexpressionina3-dimensionalcitymodel(3DCM).Themainreasonisthatthecloverleafjunctionisofteninacomplexandenormousconstruction.Itsmainbodyisbestraddleinair,andhasaerialintersectionsbetweenitsparts.Thiscomplexfeaturemadecloverleafjunctionquitedifferentfrombuildingsandterrain,therefore,itisdifficulttoexpressthiskindofspatialobjectsinthesamewayasforbuildingsandterrain.Inthispaper,authorsanalyzespatialcharacteristicsofcloverleafjunction,proposeanall-constraintpointsTINalgorithmtopartitioncloverleafjunctionroadsurface,anddevelopamethodtovisualizecloverleafjunctionroadsurfaceusingTIN.Inordertomanagecloverleafjunctiondataefficiently,theauthorsalsoanalyzedthemechanismof3DCMdatamanagement,extendedBLOBtypeinrelationaldatabase,andcombinedR-treeindextomanage3Dspatialdata.Basedonthisextension,anappropriatedatastructur