Research And Application Of 3D Rail Visualization Based On DEM

With the development of rail informationization construction, geographic information system (GIS) has been widely applied in the rail domain, which provides an efficient means to rail operation and management. Nowadays, 3D visualization has become one of the hot research directions in GIS. It shows geospatial phenomenon by 3D modeling technology, which can not only express the horizontal and vertical relationship of spatial objects, but also be prone to 3D spatial analysis. 3D visualization is bound to be of great importance to rail informationization construction. Therefore, how to efficiently establish a 3D visualization scene appears to be particularly important. In addition, as the basis of spatial data, digital elevation model(DEM) is the core content of 3D visualization research. In order to match different scales of data, how to transform DEM becomes the focus of current research. Aiming at practical application in rail domain, this thesis summarizes the typical algorithm of establishing DEM, and put forward the method of DEM transformation based on wavelet theory. According to simulation and four evaluation indexes, the best parameters of DEM transformation by binary discrete wavelet can be obtained. Meanwhile, this thesis establishes different scales of DEM of Qinghai-Tibet district by VB6.0 and Matlab, and then shows the 3D terrain scene via ArcGIS. Finally, based on 3D terrain scene of Qinghai-Tibet district, 3D virtual reality system of Qinghai-Tibet Railway has been constructed, which develops some terrain analysis functions and has high practical value.