不同点密度下复杂山区轻型机载LiDAR数据DEM构建

DEM construction of airborne LiDAR data in complex mountainous areas at different densities

点云的点密度是决定DEM数据构建的关键因素。本文以云南华坪县永兴乡某复杂山地为研究区,采用随机采样算法对点云进行抽稀,获取点云保留率10%~90%共9组数据,并分别进行DEM数据建模及其精度评定。结果表明,点云保留率与DEM精度呈正相关关系,当点云保留率小于30%时,RMSE快速增大,DEM精度误差增大;当点云保留率设置为60%时,RMSE最小,DEM精度最高。该研究对大型机载LiDAR项目中的点云数据存储与使用具有一定的指导与借鉴意义。

The point density of point cloud is the key factor to determine the DEM data construction.In this paper,a complex mountain in Yongxing township,Huaping county,Yunnan province,is taken as the research area,and the random sampling algorithm is used to extract point clouds,and the retention rate of point clouds is 10%~90%.Nine groups of data are obtained,and the DEM data modeling and accuracy evaluation are carried out respectively.The results show that there is a positive correlation between the point cloud retention rate and DEM accuracy.When the point cloud retention rate is less than 30%,the RMSE and the DEM accuracy error increases rapidly.When the point cloud retention rate is set to 60%,the RMSE is the smallest and the DEM accuracy is the highest.This research has certain guidance and reference significance for the storage and use of point cloud data in large airborne LiDAR project.