Abstract: Defensive boundary as a basic linear terrain feature, it has broad application outlook in military field and civil field. However in the published literature extraction of defensive boundary only considers its visible range characteristic. Besides, because the accuracy is poor, defensive boundary extracted by existing methods cannot support the practical application. In this paper, a new defensive boundary extraction method focusing on the micro physical characteristic of the local defensive boundary is proposed. It analyzes the slope changes of mountain surface by using sliding window, and then screens out the feature points whose slope changes sharp, and finally combines with other constrains forming the defensive boundary. The results of the experiment show that the extracted feature lines accord with requirements of fortification.

Key words: defensive boundary, micro terrain factors, section subdivision, slope mutation

摘要： 防界线作为一种基本的线状地形特征，在军事领域和民用领域都有着广泛的应用前景。现有的提取技术仅考虑防界线的可视域特性，所提取的结果偏差大，不足以支持实际应用。为此，提出一种防界线提取方法，该方法着眼于防界线局部的微观形态特征，利用滑动窗口分析山体曲面的坡度变化情况，筛选出坡度变化剧烈的特征点并结合其他约束条件形成防界线。实验结果表明，所提取的特征线符合设防要求。

关键词: 防界线, 微观地形因子, 断面剖分, 坡度突变