Application And Research Of Cartographic Generalization Technology In Railway Electronic Map

In recent years, with the popularization and promotion of the "digital railway" concept and system implementation, the railway electronic map has become the necessary infrastructure of the railway informatization construction. Railway electronic map provides railway thematic geographic information resources, intuitive geographic information and geographic information to support decision analysis for each railway departments or systems, it can improve the scientific decision-making level and information utilization efficiency of existing business in railway operation department. Geographic information is an important part of railway information resources, how to accurately and scientific express railway geographic information in railway electronic map is the focus issue for the railway map cartographers.Railway geographic information implement the intelligent visual expression by cartography generalization method, it is also the important expression of intelligent for the railway electronic map. Through level of detail to take the attributive classification for geographic information, the current expression in railway electronic map mainly according the display requirements to takes coverage then realizing the presentation, but the refinement degree of hierarchical directly affects the display of the map. While cartographic generalizetion technology is, according to the map display demand and combines with the factors that affect the map display, the method that using intelligent calculation method to solve the map display elements’ optimal expression, takes the visual map graph to expand as using digitization method to scientific describe the geographical spatial distribution and mutual relations. Therefore, this thesis presents a railway electronic map based on the technology of cartographic generalization, to satisfy the intelligent expression of railway geographic landform and display the railway geographical position scientific and accuracy.By study the role of cartographic generalization technology in mapping, the thesis concludes that the cartographic generalization technology is an effective method to improve map expression level, through the introducing of the cartographic generalization technology process, confirms the research contents is the expression and selection of railway location. Cartographic generalization technology is the external embodiment of graphics thought and cartographic generalization knowledge is its standard, through the introduction of cartographic generalization knowledge, the thesis stipulates the knowledge organization for railway points cartographic generalization to guide the points selection criteria in the process of cartographic generalization. Factors to consider in the process of cartographic generalizetion should not only consider the points own characteristic, but also keep the railway points spatial distribution characteristics, guided by the cartographic generalization knowledge to form cartographic generalization model for railway points, and use bacterial foraging algorithm to solve the model, then to realize the railway points cartographic generalization and applicate in railway electronic map. The railway electronic map is currently running on Lanzhou railway police security bureau guard duty command system, the railway points expression have a good use value.