Elevation data Ullensaker Nes Nannestad 2010

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).高程数据可精细化刻画地形与地表的形态特征。此类数据可通过机载激光扫描生成点云，或经由航空影像匹配运算得到点云。 针对不同应用需求，该点云的点密度（点/平方米）存在差异。 基于该点云，可生成网格格式的地形高程模型（DTM, Digital Terrain Model）与地表高程模型（DOM, Digital Surface Model）。