矢量地图空间信息度量及其变化分析方法

Measurements of Geospatial Information and Their Changes for Vector Map

如何计算地图的空间信息含量是评价制图质量、地图综合算法以及实现空间信息有效传输的重要基础。论文在详细分析现有的空间信息度量方法的基础上,提出了一种空间信息度量的新方法。该方法分别从几何、专题、拓扑以及专题拓扑4个方面来度量地图空间信息。然后,提出利用膨胀和序贯膨胀形态学算子分析几何信息熵、专题信息熵、拓扑信息熵以及专题拓扑信息熵随地图符号影响范围不同而引起的变化。通过算例分析发现,利用Voronoi图计算得到的结果是论文方法的一个极值结果(即特例),并且该方法便于定量分析地图空间信息熵度量随符号影响范围(或大小)的变化情况。

Measuring the content of geospatial information are the key to evaluating cartographic quality and generalization algorithm, and transferring of geospatial information. To develop a set of new measurements for geospatial information, this paper firstly makes a critical examination of the existing approaches for geospatial information measurement. And then, a reclassification of contents of geospatial information is made considering geometric, thematic, topological and thematic topology. Tbe corresponding measurements are further developed, including geometric information entropy, thematic information entropy, topological information entropy and thematic topological information entropy. Based on it, the morphology operators, i.e. dilation and sequential dilation, are used to analyze the changes of geospatial information with the incidence of map symbols. It has been shown by an example that the result obtained by Voronoi diagram is an extremum of proposed method in this paper. Indeed, our method is able to provide a series of entropy measurements with different times of dilations for map symbols.