矢量线与球面DQG地形集成的几何叠加算法

Geometric overlay algorithm for integration of vector polyline and dem based on spherical DQG

为解决在矢量线与地形的多尺度叠加操作中出现的穿地或跨越问题.利用退化四叉树球面格网,提出矢量线所经过球面格网单元的定向搜索方法以及基于定向搜索的几何叠加算法,采用全球GTOPO30(1 km)和局部区域ASTER GDEM高程数据(30 m)以及DCW道路矢量线进行算法测试实验.研究结果表明:基于定向搜索的几何叠加算法有效实现了矢量线与球面地形格网的无缝集成,避免了矢量线对地表的穿越现象.该研究成果实现了传统几何法从平面欧式空间向球面流形空间的扩展应用.

In order to avoid the phenomenon of vector polyline going across DEM during the multi-scale overlay operation, based on the spherical DQG framework, a directed search algorithm for finding DQG cells across by vector polyline was developed, then geometric overlay algorithm was presented for the seamless integration of vector polyline and terrain surface. Finally, an experiment platform was developed by using the context of VC++language and OpenGL 3D API. GTOPO30 data, ASTER GDEM and DCW roads data sets were selected to demonstrate the performance of algorithms. The results show that geometric overlay algorithm achieved the seamless integration of vector polyline and terrain, and avoided the penetration phenomenon of the vector polyline towards terrain. This study effectively extends the traditional geometry-based method from plane Euclidean space to spherical conformal space.