Rail-based Google Earth Three-dimensional Space For Line System Research

Railway location design is the basic preparation work in railway construction. The design results have a direct impact to the railway construction costs, operating costs,service capacity and service quality etc.However, in the early planning stages the railway design is often plagued by lack of basic data, topographic mapping time is early, and many surface features such as new houses, factories, road networks, airports,stations etc.are missing, and geographical information is also lack, so it is difficult to improve the railway design efficiency and quality. The emergence of Digital Earth software represented by Google Earth provides a good solution to these problems.Therefore,this thesis presented a Digital Earth based three-dimensional railway location design thinking, and thoroughly studied the applications of Google Earth based railway route selection.The chief research contents and achievements could be summarized as follows:(1)With the guidance of Software Engineering methods,this paper analyzed and designed the overall objectives;general structure,functional module and work flow of the Google Earth based three-dimensional railway location design system, and briefly introduced the related development technologies.(2)In the light of coordinate transformation theory and images splice theory, the fast acquisition and processing of Google Earth terrain coordinates data and images, have been realized. So that the data obtained can be used as the data sources of digital terrain models, topographic map, plane, vertical, cross section design, and three-dimensional scene simulation.The data meets the needs of the planning stage,and can provide important reference for the detailed design.(3)This thesis deeply studied the principles and algorithms such as the key calculation for railway, graphical display and graphics interactive mechanisms etc.According to these principles and algorithms, the Google Earth based plane interaction alignment and the location design for vertical gradient change points, stations, bridges and tunnels, have been realized.This method improves the efficiency of planning and design.(4)The railway design program comprhensive exhibition in the Google Earth platform has been realized. The system can show single design program professional information on lines, bridges, tunnels, stations, geology etc.,and can simultaneously display more than one design program, which provides a platform for the project evaluation and assessment.(5)Combining with the concerned research and development projects sponsored by the National Natural Science Foundation and China Railway Eryuan Engineering Group CO.LTD,and under the guidance of the instructor and with assistance of other comrades, and in the light of those theories and algorithms stated in this thesis, adopting those developing tools or interfaces of C#,C++, Google Earth COM API,KML, and ARX etc, the author developed a Google Earth based 3D railway design system. The system has been applied widely in many rails alignment and design, such as the Chengdu-Chongqing intercity rail,the Bijie-Xingyi railway, the AnKang-Zhangjiajie railway, the Yuxi-Mohan railway, the Zhengzhou-Wanzhou railway, the Angola railway, the Mecca light rail in Saudi Arabia etc.These theories and methods stated in this thesis have been verified by a large number of practices.