GIS中的测地距离及其求取方法

在利用ＧＩＳ进行空间分析的过程中，常常会遇到求取某一连通域内两点间最短路径和相应的距离这类问题，传统上使用的欧氏距离对此有较大的局限性。本文把测地距离的概念引入到矢量型ＧＩＳ中，并讨论了测地距离的若干性质；在此基础上，提出了一种简便有效的求取矢量型ＧＩＳ中两点间测地距离的方法，并编写了相应的程序。实际应用表明文中所提出的方法是切实可行的，有效地克服了欧氏距离的局限性。

The Concept and Algorithms of Geodesic Distance in GIS

In the process of space analysis to geographical information in GIS. the problems as to find minumum path and calculation the corresponding distance between two points in a connected domain are common. The Euclidean distance. which is traditionally used in GIS. Is possibly ineffective to this kind of problems in some situations. The conceptof geodesic distance is introduced to GIS with vector data structure in this paper. Some characteristics of geodesic distance are also discussed. On this basis. an approach to calculate the geodesic distance in GIS is put forward and the corresponding computer programmes are developed. The experiments show that the algorithms developed in this paper are practicalble and effective.