摘要
可视性分析广泛应用于G IS的各个方面,视线和视域是其最基本的两个因子。视域的计算方法有很多种,在计算时因为采用的算法和实现算法所运用的编程方法的不同,导致计算耗时间和准确度有很大的差异。该文首先对这两个因子所涉及的算法加以分析,然后用VC++.NET中的COM组件编程实现了视线和视域计算接口,并通过程序模拟生成评估的视域图,比较了各个算法在相同外界条件下的CPU时间消耗和计算准确度,得出XD raw是比较准确且CPU耗散较小的算法的结论。同时也分析了各算法之间相似程度的度量。
Visibility analysis has been widely used in GIS applications. Viewshed and LOS are its two elementary factors. There have been many methods for viewshed computing using different algorithms and programming techniques, which lead to big differences in consumed time and accuracy. Firstly, this paper analyses the basic algorithms which the two factors refer to, and then implements the LOS and viewshed computing interfaces using COM programming in VC ＋ ＋. NET, at the same time , the programs create many different viewshed maps and record the correspondingly consumed time. By comparing different CPU time cost and viewshed maps under the same conditions, it figures out that XDraw is the one with less time and higher accuracy. Meanwhile, the paper analyses the comparability between different algorithms.
出处
《计算机仿真》
CSCD
2006年第5期171-176,共6页
Computer Simulation
关键词
视线
视域
数字高程模型
通视
Line of sight
Viewshed
Digital elevation model
Intervisibility
