中文摘要：

目的实时逼真地可视化表达整个地球表面。方法基于椭球面三角形格网完成对地球表面的建模表达，通过分层分块来组织全球数字高程模型（DEM）数据，基于椭球面三角格网的递归细分生成多分辨率地形模型。结果将全球地形数据共分成4层，最高分辨率的数据层包括256个菱形块数据文件，最低分辨率的数据层为4个菱形块数据文件，中间分辨率数据层分别有64和16个数据文件。实现了从全球到局部不同分辨率层次数据的快速动态替换。结论建模方法从根本上避免了传统DEM在处理全球地形时带来的问题，且易于实时多分辨率模型的生成，满足全球地形数据快速浏览的要求。

英文摘要：

Aim To realize real-time and realistic visualization of the Earth surface. Methods A digital elevation model based on the ellipsoidal triangular meshes is made to approximate to the Earth surface, and the terrain data are organized into different resolution levels and data tiling. A multi-resolution model is built through recursive sub- division of each ellipsoidal triangle. Results The globe terrain data were divided into four levels, the high resolu- tion level including 256 diamond data files, the low resolution data level including 4 diamond data files, the moder- ate resolution data levels including separately 64 and 16 data files. The fast dynamic replacement among the differ- ence resolution level data from globe to region was realized. Conclusion This method overcomes the problem caused by the traditional DEM in dealing with the global terrain surface and it is easy to realize real-time rendering and multi-resolution modeling of the Earth surface.