An algorithm for extracting terrain structure lines based on contourdata

摘要

Terrain structure lines are lines that indicate significant topographic features of the terrain. It is widely used in the field of surveying and mapping, GIS, topography representation and engineering designing. Digitized contour data contains the information of these structure lines implicitly. In this paper, the authors investigate the problem of the extraction of terrain structure lines, and discuss the existing methods for the extraction of terrain structure lines. After analyzing the existing method theoretically, conclude that it is very important to make full use of data information in extracting terrain structure lines, and put forward a new brief and practical algorithm for auto extracting terrain lines from digital terrain data. The new algorithm extracts terrain feature points by making digital contour lines into sections; identifies and classifies character points; finally extracts ridge and valley lines. The algorithm combines geometry and physics characteristics of ridge or valley line. Experiment result shows that the ridge and valley extracted by the arithmetic is concord to the terrain, and proves that the new algorithm is quite effective and reliable for extracting terrain structure lines.