Tiled Transforming Of Terrain Along Railway And Its Web Service

China’s high-speed railway is being built rapidly now.With the development of computer information and GIS technology,the full life-cycle 3D GIS for survey and design,construction and safe operation of railway industry has become the trend of modern railway development.Terrain is the basis of 3D virtual scene of railway,in order to display elements such as roadbed and slope realistically,terrain reconstruction by characteristics of railway roadbed is needed.And fast transmission,interactive design and Immediate release is the new demand under the WebGIS environment.This paper discusses the pyramid model construction method applied to the DTM theory and the large scene required for the construction of VGE along the railway,it also analyzes the key attributes and construction method of the railway terrain and studies the QuantizedMesh and its suitability for railway terrain.This paper designs algorithm for virtual reconstruction of railway feature terrain and simplifies method of terrain.The Web service of railway terrain data which can be published and interactively modified on WebGIS is designed and implemented.Finally,the effectiveness of the tile-based algorithm and the reliability of the Web service are verified by the high-speed railway simulation system.The conclusions of this paper can be applied to the 3D simulation of railway.It can provide a visual platform for the route management and reduce the workload and working time of survey and design.It can also be used for highway design and other traffic information engineering needing terrain reconstruction.