等值线DEM地形特征点提取与分类

Terrain Characteristic Point Extraction and Classification from Contour DEM

地形特征按照相应特征模式隐含于DEM中,如何从DEM尽可能自动而准确的提取地形特征始终是测绘空间信息科学的重要而基础的问题。等值线是地形地貌DEM的最一般形式。地形特征点是生成高层次地形特征线面的基础,与局部地形起伏密切相关。在等值线DEM中,特征点的获取与分类不但与当前等值线的几何形态变化有关,也与局部区域内相邻等值线有密切而复杂的关系。本文在分析各种等值线特征点提取方法的基础上,讨论等值线内部和相邻等值线之间关系的多种复杂情况,形成我们实用的等值线特征点类型判断和提取方法,并进行具体的数学推导和应用到实际地形等值线的特征提取试验中。试验结果表明,我们的提取分类方法能解决多种复杂等值线变化的情况下获取地形特征点,并取得较准确可靠的结果。

Terrain characteristic is potential but solid content in DEM with their due modes. It is a basic but fundamental question on how to extract them with most possible accurate and automatic way in Geo-Informatics. Contour is a most general expression of DEM. Terrain characteristic points are the basic elements of characteristic lines and faces, and closely connect with the local terrain variation. In contour DEM, characteristic point＇s extraction and classification are not only related with the current contour＇s geometric shape, but associated with the near contours closely and complicatedly. In this paper, we discussed different contour characteristic points＇ extraction method and analyzed several complicated things in current contour and among near contours with relevant theory, thus obtained our own characteristic point extracting and classification method.The experiment shows that our practical method makes quite reliable result of terrain characteristic point＇ s extraction and classification in complicated and real contour DEM data.