以四川理县一地质滑坡为例,分析扫描点空间位置的理论精度,探讨点云数据获取以及点云过滤、点云拼接、地理参考等数据预处理的关键技术,给出一套比较直观、全面的滑坡形变分析方法,包括基于点云比较的形变分析、基于TIN比较的形变分析、基于特征点的形变分析以及基于DEM的形变分析。为了充分利用非地面点云数据,提出一种提取滑坡区域电线杆、树干的几何特征来分析滑坡水平变化的新方法。通过分析得到的滑坡形变量与GNSS远程实时监测结果基本一致。
Theoretical precision of scanning points is analyzed and some key techniques, such as point cloud data acquisition and point cloud data preprocessing are discussed with an example of a landslide in Sichuan Lixian. Then a very intuitive and comprehensive landslide deformation analysis method is presented in this paper. Furthermore, a new method of extracting the geometric features of telegraph poles and tree trunks in the landslide area is presented in order to make the best of non-ground point cloud data.