Evaluating topological relationships of the objects in 3D GIS and network analysis

In this study, it is aimed that to design a conceptual model and develop a 3D GIS application for indoors which can be performed efficient network analysis. A functional and analysis based GIS prototype was implemented based on modeling fundamentals and mathematical infrastructure of 3D network analysis applications. The system consists of four components; Automatic Data Generation, Network Analysis, Simulation, and Navigation. A new method, MUSCLE (Multidirectional Scanning for Line Extraction) Model was developed for Automatic Data Generation. By using this method, it is possible to efficiently and automatically generate 3D Building and Network Models based on the floor plans of the building. Therefore, the method is basically an image processing method and can be used for automatic vectorization of raster images in general. Network Analysis component has two functions; analysis and visualization. By using analysis function, the users can select two entities in the building and optimum path between them is calculated. By using visualization function, it is possible to view and navigate the 3D Models and optimum path on the screen. In this application, it was indicated that the 3D network analysis -which is the one of the most important analysis for indoors- can be performed efficiently. Simulation component was developed for modeling the movements of a person in the building. In this application, navigation of the person is simulated as audible and visual. In the navigation component, by using a user interactive positioning method, it was indicated that a person can be reached his target without any problem. The areas such as evacuation and address finding, etc. are the subjects of this kind of applications. The thesis consists of four sections. In the first section, the 3D GIS concept is explained and the difficulties in realizing 3D GIS or 3D geo-spatial systems are evaluated. The problem and the aim of thesis are defined. Then, the scope is revealed and subjects of the thesis such as emergency services, transportation, security, visitor guiding, service organization etc. are detailed. The overview and methodology are also the part of the first section. In the second section, the fundamentals of the 3D Network Analysis are investigated. Types of the network analysis and topology concept are explained. Mathematical infrastructure of the network analysis, Graph Theory, is described on a vast scale. Shortest path algorithms are presented using detailed examples. In the third section, developed system is introduced. Conceptual and logical design processes explained. Mathematical and algorithmic fundamentals of the system are described in detail. The fourth section includes the results and suggestions. Keywords: Geographic information system (GIS), 3D GIS, automatic feature extraction, network analysis, topology, simulation, navigation