| Transportation, a vital component in people's daily life, is a significant applied field to GIS. In general, more complicated transportation phenomenon needs support of 3D GIS theory, but at the same time a series of problems will emerge which need be solved. The dissertation will focus on the problems created while 3D GIS describing complex road transportation phenomenon. The key contents of the dissertation is to develop a 3D data model, which can describe complex transportation features, organization and management of 3D road data, including topology relation data about road network, multi-resolution dynamic simplification algorithm of irregular road network and terrain integrated model and spatial index method based on road network 3D data, etc. The main research work of this dissertation is as follows:1. Research progress of relevant work is reviewed. The dissertation introduces present research situation about linear data model of GIS-T, 3D data model, management of 3D data and 3D visualization technology.2. LRS and dynamic segmentation is the characteristic and leading technology of GIS-T. Therefore, after discussing LRS and dynamic segmentation, the establishment method of linear reference datum and transformation method between linear coordinate and spatial coordinate are talked over in the dissertation. To apply it to dynamic segment of 3D Geometry data, the dissertation also extends dynamic segmentation model to organization for 3D Geometry data, which makes it possible to the combination of 3D GIS and GIS-T.3. Basic modeling elements on topology and Geometry of road network are discussed and expression approach of terrain model considered road network is mentioned. In the basis of this, this paper integrates LRS and dynamic segment to the model. Using the method of object-oriented, 3D GIS model applied to transportation is developed, which can provide theory basis for the combination of 3D-GIS and GIS-T.4. The management on 3D-data is an important content of 3D GIS. After irregular road network is integrated to terrain model, it is difficult to divide the model into regular patches. Accordingly, data management on road model and terrain model becomes more sophisticated. The managements about road TIN data, affiliated facilities data and terrain model data are talked over in the dissertation. Aimed at 3D data model of transportation network mentioned, the dissertation firstly reviews the storage structure of triangle network and improves the structure of edge, vertex and triangle. Next, base on file and database management approach for triangle data on are discussed, and database storage structure of irregular triangle is designed. The dissertation also discusses management of road multi-overlap attribute data, designs the structure of 3D road Geometry data and database storage structure and then talks over database management on 3D model. To the moving objects, a type of data structure with dynamic segment is proposed to store the data on history tracks, which can save on data storage spacegreatly. Eventually, the dissertation recalls present expression approach about road network topology data and designs the structure on topology data based on 3D Geometry network and physical realizing structure on database.5. The relevant work on LOD model is introduced. By analyzing progressive mesh (PM) algorithm, the dissertation points out some problems when employed to road network model. In terms of characteristic of mesh model integrated by terrain and road model, the dissertation proposes LOD algorithm based on multi-resolution of irregular triangle network with the structure in the shape of "IhJ". The algorithm, with the viewpoint as its central, designs resolution levels and controlling error orderly according to the distance. The algorithm solves the problem on which the model is difficult to recover during edge collapse by controlling the depth of vertex tree, and avoids the emerging of intersecting, overlapping or slender triangle base on relative experiment results.6. Irregular road network 3D data advances a new demand to traditional method of multi-dimensional index. The dissertation firstly analyses R-tree index and procedure of establishment and then raises hybrid index mechanism combined integrated connection with dynamic segmentation according to the characteristic of road network inter-connected. Next, the principle, establishment procedure and query steps about connective index are elaborated in the dissertation and hybrid index mechanism are compared with R-tree index in space and query efficiency base on experiments. Finally, the dissertation narrates the dynamic loading process of 3D data on road network.7. The exploitation of experiment system. Based on data model and algorithm proposed this paper, with VC++ and OpenGL as exploiting tools, the experimental software system, having the functions on 3D model of establishing, editing, visualization and transportation analysis, is developed. Base on the experimental system, we can realize the model and algorithm mentioned in this paper.Principal contributions include:1. 2D LRS and dynamic segmentation technology are extended to come true dynamic segmentation of Geometry data on road network, which can provide a better condition for the combination of 3D-GIS and GIS-T.2. A 3D data model, expressing complicated road transportation phenomenon and considering visualization and spatial operation, is developed, which furnishes the theory basis for 3D GIS and GIS-T. 3D data model not only enriches the contents about digital city but also has great significance in promoting the application of GIS in transportation field.3. Aimed at 3D data model of transportation network, this paper improves structure of vertex, edge and triangle. After that, the data structure of irregular triangle network, 3D road Geometry and attribute data based on dynamic segmentation organization is designed. To the moving objects, a type of data structure with dynamic segment is proposed to store the data on history track, which can reduce the amount of data greatly. The dissertation advances topology data based on 3D Geometry network and physical realizing structure on database.4. After the integration of terrain and road model, the mesh is usually irregular. Focus on this characteristic of the integration mesh, the paper proposes LOD algorithm based on multi-resolution of irregular triangle network with the structure in the shape of "0". The algorithm, with the viewpoint as its central, design resolution levels and controlling error orderly according to the distance. The algorithm solves the problem on which the model is difficult to recover during edge collapse by controlling the depth of vertex tree. The algorithm avoids the emerging of intersecting, overlapping or slender triangle base on relative experiment results.5. 3D data on irregular road network brings forward a new demand to traditional method of multi-dimensional index. The paper put up a spatial index method based on interlinked topology, which can build up index for the central line of road. It is well known that the data is along the road in a linear way and the roads connect to each other. According to the above characteristic, a hybrid indexing mechanism combine connecting with dynamic segment is proposed in this paper, which can realize the query process in two steps. The first step is to search rough by connecting index. Based on the results of the first step, the second step can finish the exact query process satisfactorily using dynamic segmentation index. This index mechanism with high query speed guarantees speed of loading data dynamically, and fulfills the demand of visualization of road network.
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