3d Digital Topographic Map Making Methods

3D digital topographic map breaks through spatial limitation and develops traditional 2D digital topographic map into three dimensional geography spatial information, from which we can understand and express real world as well as the spatial structure relationship. The thesis discusses the theory and application of 3D digital topographic map in surveying, drawing and applications. The main works and contributions are summarized as follows:1 2D digital topographic map's limitation is summarized, and the significance and needs of 3D digital topographic map research's are put forward: Three dimensional space information acquisition, three dimensional terrain and ground feature making method and visualization expression, three dimensional terrain and ground feature integration matching technique and three dimensional space analysis function.2 The common 3D space data collecting method and the new gathering technology characteristic have been introduced. The terrain and ground feature spatial data characteristic, especially altitude information of the ground feature have been analyzed. The accuracy and complement of 3D digital topographic map are based on massive, careful data acquisition.3 Compared with commonly used triangulated irregular network(TIN) and regular Gird when expressing the terrain, proposed that uses triangulated irregular network (TIN) restraint to produce terrain, based on this through interpolation elevational point establishment the regular Gird, auxiliary by elevation number method expression three dimensional terrain. Emphatically the analysis and through the experiment shows the three dimensional regular Gird when the expression extreme terrain for example steep mountain cliff (ridge/shore), the hollow of terrain has superiority.4 According to 3D digital topographic map's characteristic, proposed that punctual, striation, surface shape and body shape four kind of ground feature concrete making methods, through the experiment realizes three dimensional visualization effect which contrasts two dimensional ground feature symbol, manifests the three dimensional ground feature expression superiority. Then on the terrain and ground feature making's foundation, in view of the different ground feature type proposed that realizes the both integration matching solution.5 Proposed that based on the AutoCAD 3D digital topographic map's application platform and based on the ArcScene 3D digital topographic map's visualization platform, specifically through the experiment demonstrates AutoCAD and the ArcScene two kind of three dimensional platform construction flows, and performs on its three dimensional function characteristic quite to explain separately.6 3D space calculating, 3D digital terrain analysis (slope/aspect analysis, section plane analysis and valley keel characteristic analysis) and the flood submergence analysis algorithm have been studied, and realizes through the experiment .