退化四叉树格网的全球多分辨率DEM无缝表达

Seamless Expression of the Global Multi-resolution DEMs Based on Degenerate Quadtree Grids

为实现全球多分辨率地形快速、高效模拟与可视化表达,探讨基于球面退化四叉树的全球多分辨率DEM无缝建模方法。提出一种基于球面退化四叉树的全球DEM分块建模方法;设计并实现了四叉树块内(相邻节点间相差任意剖分层次)、四叉树块间、四叉树与非四叉树块间的自适应无缝拼接算法;应用VC++语言和OpenGL工具,设计开发了相应的可视化试验系统。结果表明:该模型方法可实现全球多分辨率DEM的无缝表达,并在保证精度的同时有效简化了全球DEM格网的数目,简化效率为66.8%(剖分层次为12)。

In order to realize simulation and visualization of global multi-resolution terrain efficiently, a seamless modeling method of the global multi-resolution DEM is discussed based on spherical DQG （degenerate quadtree grid）. The main contents are as follows, Firstly, a new modeling method of global block quadtree based on DQG is developed. Then, a self-adaptable seamless stitching algorithm is designed and achieved in which the cracks exist within a quadtree block （the adjacent nodes is arbitrary subdivision levels）, between the different quadtree blocks, or between a quadtree block and a non-quadtree block experimental system is developed and the results show this modeling method and the grid number is simplified simplification efficiency is 66.8% in 12th level of DQG, Finally, by using VC ＋4- language and QpenGL tools, an that the global DEM can be expressed seamlessly by using efficiently while ensuring the accuracy of the terrain. The