Research On The Process Method Of Railway Spatial Information's Multi-scale Transform And Its Application

Railway Transportation Systems which are regarded as distributed systems is nearly correlated with the spatial location, and the information servers based on spatial date is being the main need for the RTS. Specially, the spatial data of the railway has the characteristics of great capacity, multi-scale, high-resolution, and so on. So widely information services for the investigation, design, plan, operation, management and decision-making support in railway industries, by treating fundamental spatial data and business data characterized by multi-scale and multi-resolution in rail-based transport sub systems. The application of railway spatial data focuses on the usage of simple data, the objects described by spatial data, and the regulation deduction based on spatial data. Different analysis tasks are allocated to spatial data with different scales. Because spatial data cannot be stored in full-scales for its huge storage requirement and limited storage of databases, as well as it would be a big waste of space that same data was saved many times under many scales. So, the problems in Railway Transportation Systems need to be considered from the perspective of spatial information scale transition.According to demands from the engineering application, the thesis describes a process method of multi-scale transform of railway spatial information based on the theories and methods of the information automatic generalization, and we also add the knowledge control through all the process. Therefore, the process has the main characteristics of automatic and intellectualized, and shows a new way to solve the problem of multi-scale transform of railway spatial information; and also the thesis analyses the hypostasis of the multi-scale transform by using the similarity theory of the fractal theory, then establishes space sequences in several different scales based on the theory of variable fractal dimension. At last the thesis proposes a model of the multi scale transition for the lines based on fractal theory, this model can main the configuration of the line, has high compressibility, and applies the model to the multi scale transition for related spatial data around railway lines. The result shows that the fractal theory has big advantage on multi-scale transition.At last the thesis applies the process to the Qinghai-Tibet Railway Geographic Information Systems, application proves the rationality and useful. Transferring the different line shows this process's advancement and rationality.