基于车载激光扫描的带状地物表面快速重建

Rapid Surface Modeling of Large Strip Objects Based on Vehicle-borne Laser Scanning

根据带状地物空间形态特征以及车载激光扫描系统对带状地物数据采集的特点,提出对相邻两条扫描线数据构建三角网进而完成整个带状地物表面快速重建方法。该方法充分利用了每条扫描线获取带状地物横截面的特点,相邻两条扫描线构建的三角网能准确地反映其所覆盖的狭长条带区域的形态结构,把所有狭长条带连接起来便能准确地描述整个带状地物的形态结构。在网格构建过程中自动建立点、线、面间的拓扑关系或隐含拓扑关系,查询和动态更新操作都限制在非常狭小的范围内,便于快速重建。

Some large objects, such as roads, bridges, tunnels and so on, have strip characteristics in spatial structure, so vehicle-borne laser scanning system has great advantage in gathering 3D information of these large strip objects, Laser scanners can record all the detectable data of the ground objects when gathering information and acquiring many scan lines, each scan＇line data in fact is equivalent to a cross section of the strip object, and these scan lines can divide the object into many narrow regions. If we build triangular mesh with two adjacent scan lines data, the corresponding narrow region will be overlapped accurately by the triangular mesh. All of the triangular meshes were merged into one big triangular mesh naturally without any extra operation and the whole large strip object is accurately described by this big triangular mesh. Topological relations were built automatically. Dynamic update was limited in the limited range and fit for rapid modeling.