Abstract: Aerial LiDAR system can get high intensive point clouds of the earth’s surface, yet also present large redundant point clouds especially in the overlapping trips area. It proposes a novel GPS time value histogram-based method for removing those redundant point clouds without track information. The method is impletmented through the three steps at below. The GPS time value histogram of the point clouds is established and consequently the bounding rectangles of strip overlapping area and overlapping point clouds in the bounding rectangles are obtained. The building points in the bounding rectangles are extracted by using some classical filtering algorithms and separately stored due to its benefit for building reconstruction. The remaining point clouds are organized as grids and the redundant point clouds in each grid are removed according to the GPS time value histogram. The experimental results show that the method on one hand can quickly and efficiently remove the redundant point clouds in the overlapping area without track information, on the other hand can better preserve the building points to improve the efficiency of subsequent data analysis and applications.

Key words: airborne LiDAR, scan angle, strip overlapping area, time histogram, buildings

摘要： 机载LiDAR系统在获取高密度地表点云的同时，也带来了数据冗余的问题，特别是在航带重叠区中尤为突出。旨在研究无完整航迹信息辅助下去除航带重叠点，提出了基于点云GPS时间直方图的去除航带重叠点的方法。该方法包括三个步骤：（1）建立点云的GPS时间直方图，并根据GPS时间直方图特点获取航带重叠区外包矩形以及外包矩形中的所有点云；（2）考虑到城市中高密度点云有助于建筑物的三维重建，通过滤波分类处理获取建筑物点并予以全部保留；（3）对重叠区中除建筑物点外的其他所有点进行格网数据组织并根据GPS时间直方图逐格网去除航带冗余点。实验结果表明，该方法能较好地保留建筑物点的同时高效去除航带重叠点且不依赖于航迹信息，提高了后续数据分析处理的效率。

关键词: 机载LiDAR, 扫描角, 航带重叠区, 时间直方图, 建筑物