Elevation data NDH Ifjordfjellet 2pkt 2017

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）可精细化刻画地形与地表特征。该类数据可通过机载激光扫描生成点云（point clouds），或由航空影像匹配得到点云。此类点云会根据不同应用需求，设置差异化的点密度（单位：点/平方米）。 基于上述点云数据，可生成格网格式的数字地形模型（DTM，Digital Terrain Model）与数字地表模型（DOM，Digital Surface Model）。