机载LiDAR点云密度与DEM产品精度关系研究

Relationship Between Airborne LiDAR Point Cloud Density and DEM Product Accuracy

对点云密度与数字高程模型(digital elevation mo-del, DEM)产品质量之间的对应关系进行研究,以获得具有指导意义的参数。首先依据香农采样定理,对生产不同比例尺DEM产品所需要的点云密度进行理论推导和论证,然后以1∶2 000、1∶1 000、1∶500比例尺DEM数据为例,用平地、丘陵、山区3种地形数据进行实验。结果表明,使用理论推导密度的点云数据在平地区域可以生产出满足精度要求的DEM产品,但在丘陵及山地区域需要适当增大点云密度。

The corresponding relationship between point cloud density and the accuracy of digital elevation model(DEM) product is studied to obtain the guiding parameters. Firstly, according to Shannon sampling theorem, the appropriate point cloud densities for production of different scales DEM in theory are theoretically deduced and demonstrated. Then, the terrain data in flat, hilly and mountainous areas are experimented with DEM data of 1∶2 000, 1∶1 000 and 1∶500 scale. The results show that for DEM product ge-neration which meets the precision requirement, the theoretical density is enough in flat area, but it needs to be increased in hilly and mountainous area. The results also show that DEM products meeting the precision requirements can be produced in the flat area by using the theoretically derived point cloud density. But it is necessary to increase the point cloud density appropriately in hilly and mountainous areas.