基于机载激光雷达点云的断裂线自动提取方法

Automatic breakline extraction from LIDAR point clouds

基于机载激光雷达(LIDAR)点云生产高精度的数字高程模型(DTM)需要进行断裂线的存储与表达,在分析现有断裂线提取方法不足的基础上,提出一种从LIDAR点云自动提取断裂线的方法。该方法利用离散的点云构建三角网,建立点云之间的拓扑关系,根据三角网面片之间的法向差异提取候选断裂线点,采用"方向优先"追踪策略实现断裂线的追踪处理,并利用"线性迭代法"实现断裂线的光滑输出。实验结果表明,该方法可以快速从LIDAR点云中自动提取断裂线信息,具有一定的应用价值。

For producing high quality Digital Terrain Model （DTM） based on Light Detection And Ranging （LIDAR） point clouds, breaklines must be explicitly stored and represented within the data structure. Having analyzed traditional methods＇ deficiencies in breakline extraction, the paper proposed an automatic extraction method. To accomplish breakline extraction, the method processed LIDAR point clouds in three steps. The first step, a mesh surface was reconstructed to establish explicit topological relation among the discrete points; the second, normal-based edge detection was applied on the irregular mesh to extract sharp borders with curvature discontinuity; finally, breaklines were traced with ＂direction priority＂ strategy and smoothed by ＂iterative interpolation＂ algorithm. The result shows that it is robust and has potential application in topographic analysis and mapping.