为了实现网络环境下虚拟地球的多尺度矢量、影像和地形数据的集成可视化,便于矢量空间数据的查询分析,本文根据几何绘制的方法,将二维矢量数据、多尺度地形和全球等经纬度离散网格集成,提出了面向虚拟地球的多尺度矢量数据结构和多尺度矢量数据分块构建与组织方法;在此基础上,针对虚拟地球中矢量数据高效可视化的要求,提出了面向可视化的Douglas-Peucker矢量数据压缩算法。最后,基于网络三维虚拟地球平台GeoGlobe开发了实验系统,实现了面向虚拟地球的多尺度矢量数据的构建、组织以及可视化。
In order to achieve the integrated visualization of multi-scale vector data, image, and terrain data on a web virtual globe and facilitate the analysis and query of vector spatial data, based on a geometry-based method, we integrate two-dimensional vector data, multi-scale terrain data, and a global latitude-longitude discrete grid. We propose a virtual globe-oriented multi-scale vector data structure with a blocked-based construction and organization method for multi-scale vector data. Furthermore, aiming at efficient visualization of vector data on a virtual globe, a visualization-oriented Douglas-Peucker vector data compression algorithm is also proposed. Finally, based on the web 3D virtual globe platform GeoGlobe, we develop an experimental system to realize the construction, organization and visualization of global multi-scale vector data. Our experimental results show that these methods are practical and efficient.