一种大型带状数字地形模型建模方法

根据铁路选线系统海量地形数据的特点，以快速、自动为目标，通过在构网建模过程中对空白区域和分块边界的处理，综合利用图形子区边界提取、异侧找点、最短距离等原则，提出了一种基于约束Delaunay三角网建立大型带状三角网的快速建模方法．通过对建立的大型三角网模型进行四叉树分割和分块存储，有效提高了建模成果的利用效率．该方法已成功地用于“虚拟环境选线系统”的开发，通过几段实际线路的应用，证明了用此方法建立连续带状数字地形模型的有效性和可靠性．

Modeling Method for Large Strip Digital Terrain Model

From the characteristics of mass terrain data in a railway location system, a practical fast algorithm for strip digital terrain model (S DTM) generation was proposed based on the constraint Delaunay TIN (triangulated irregular network). This method takes many of the characteristics of large strip terrain areas into consideration, such as obtaining the boundary of sub areas, finding out points at different sides, shortest distance, characteristic lines, and special areas, etc. The decomposition and structure of quad tree are used to large triangulated net models constructed to increase the efficiency of the generation and application of S DTMs. This method has been used in a virtual environmental railway location system. The result of application in several practical railway lines shows the validity and reliability of the proposed method to establishing continuous strip digital terrain models.