Study On The Development Of Railway Location Design System Based On GIS

Based on anatomizing the current computer aided alignment design system's limitations in data collection and management and spatial analysis ability, the theories and mthods about Railway Location Design System Based on GIS have been studied detailly in this paper, the author has established an analytical model for application of railway location design and put forward a scheme for building custom commands for the request of railway location design in GeoMedia-based applications. At the same time, the principles and methods of command development based on GeoMedia was expatiated detailly. By using the methods presented in this thesis, the author has developed a prototype of design system for urban railway location system based on GIS(PURLS).Some functions such as designing alignments, vertical profile map and establishing digital terrain model were realized in the system. Further more, the basic information database of urban railway survey and design was established to support the analytical model for application of locatiom design .The scheme and method of converting CAD data into GIS data in GeoMedia has also been presented detailly. For supporting vertical profile map design ,a practical fast algorithm for strip digital terrain model (S-DTM) generation was discussed based on the constraint Delaunay TIN (triangulated irregular network), and then it was applied to the PURLS successfully . At last, the major functions in PURLS have been tested and verified by an example. The results show that the theories employed and methods presented in this thesis are scientific and applicable.The following lists the major studies and the new points in this thesis :1. An analytical model for application of railway location design has been established.2. Based on the scheme for command development of GeoMedia,the theories and mthods about Railway Location Design System Based on GIS have been researched systematicly3. The basic information database of urban railway survey and design was established to meet the PURLS's demands for foundation data. The scheme and method of converting CAD data into GIS data in GeoMedia has also been presented detailly.4. Considering the remarkable difference in attribute between tangential path and curved path in PURLS, the author put forward an idea of storing them as individual unit in database and also realized this idea in PURLS's database well.5. A model of DTM has been built and was applied to the PURLS successfully .It provided a base for vertical profile map designing.6. Have been developed a prototype of design system for urban railway location system based on GIS.Developing a railway location design system based on GIS has an very important meaning. It improve the spatial analysis ability of railway location system and also make full use of the results of both multi-analyzing for evaluating schemes of railway location and digitial railway location design. So, the methods presented in this thesis have a great future . Studies in this thesis also lay the foundation of farther researching on development of railway location system based on GIS.