Height data Risør-Tvedestrand-Arendal_Grimstad 2015

Elevation data provides a detailed description of terrain and surface. The data are established as point clouds from airborne laser scanning or matching from aerial images. The point clouds have varying density (point/m²) for different purposes. From the point clouds, elevation models are generated on grid format of terrain (DTM) and surface (DOM).高程数据（Elevation data）可对地形与地表进行精细化描述。该类数据可通过机载激光扫描生成点云（point cloud），或借助航空影像匹配获取点云。不同应用场景下，点云的密度（单位：点/平方米）存在差异。基于点云可生成地形（DTM）与地表（DOM）的网格格式高程模型。