滚动球变换支持下的TIN-DDM地形特征线自动提取方法

针对传统规则格网数字高程模型地形特征线提取方法中存在阈值难以定量调控、连接方式无法自适应调整以及地形特征线类型不完整的问题,将滚动球变换模型应用于不规则三角网数字水深模型(triangulated irregular network digital depth model,TIN-DDM)地形特征线的自动提取,在构建临界滚动球半径关联的地形特征点定量识别判定准则基础上,引入地形形态边界点概念,采用逆向工程的建模思路,建立了以剖分单元为基础的地形特征线自动提取模型,结合地形类型判定准则的多尺度表达特性及顾及水深数值的地形特征优化模型,提出了可多尺度表达且类型完整的地形特征线自动提取方法。试验结果表明:相比于经典地表流水模拟方法,该方法可实现完整、连续且细分的TIN-DDM地形特征线自动提取及多尺度表达,且提取的地形特征线具有更高的地形重构精度。

Automatic extraction method of TIN-DDM terrain feature line supported by rolling ball transform

In view of the problems in the traditional regular grid digital elevation model terrain feature line extraction method, such as the threshold is difficult to be adjusted quantitatively, the connection mode cannot be adjusted adaptively, and the type of terrain feature line is incomplete, an automatic extraction method of TIN-DDM (triangulated irregular network digital depth model) terrain feature line based on rolling ball transformation model was proposed. Based on the judgment criterion of a quantitative identification for terrain feature points associated with the critical rolling sphere radius, the concept of terrain shape boundary points was introduced, and the automatic extraction model of terrain feature lines based on subdivision unit was established according to the modeling idea of reverse engineering. Combined with the multi-scale expression characteristics of the terrain type judgment criteria and the terrain feature optimization model considering water depth values, an automatic extraction method of terrain feature lines that can be expressed at multiple scales and complete types was proposed. The experimental results show that compared with the classical surface water simulation method, this method can automatically extract complete, continuous, subdivided and multi-scale TIN-DDM terrain feature lines, and the generated terrain feature lines have higher terrain reconstruction accuracy.