Automation of Topographic map from CAD to Geo Database in GIS

GIS software provide manual import tools to maps produced on CAD software to be transformed to geo-database. This operation consumes time and effort. The "transformation" however will not be adequate unless we analyze the relation between CAD and GIS software in preparing maps. The question raised here if this relation competitive or integrative? This research tries to answer this matter by studying it from different angles: modeling, spatial feature, scale, spatial analysis and data management. Analyses reveal that this relation isn't competitive at all, but rather integrative, as CAD software produce technical\design plans, whereas GIS software are dedicated for the production of general and thematic maps. Thus, CAD based spatial data (topographic, cadastral, master plans) could be "up-graded" to be efficient in GIS environment. However available tools to make this are basically manual, and for that, an automated approach was developed to execute this upgrade from CAD to GIS. This new approach was applied and evaluated and the output results were satisfactory accurate, time\effort saving, and indeed didn't miss any of CAD layers. This all could be achieved if being conditioned with the approach constrains.

Building 3D Digital Models For Cities in Large Topographic scales in GIS

3D GIS can be realized as an actual building platform of the urban space. This research develops automated 3D urban models that fit large-scale digital photogrammetry. Originally, modeling used manual or semi-manual techniques, and there is a need to for a development of an approach that automates the transformation of vector linear data, optimized by digital photogrammetry stations to create the 3D volume model in 3DGIS. This approach consists of three main phases: roof modeling, wall modeling and volume structuring. During the first phase, local and conditional "Delaunay Triangulation" method is used to deal with the majority of roof types regardless of its geometry. The second phase is completely automated to create the walls by the vertical projection (Top-Down) of the outer line of the roof into the Digital Terrain Model (DTM), and then by the selection of the bottom base level as the default level. Finally, different elements of the structure can be aggregated using spatial relationships (many-to-many) already supported by GIS software. The new approach is created and completely automated. It doesn't require roof geometric-types library, which asserts the GIS is a valid platform to build, to view and to store 3D urban models.