Height data Image Risør-Gjerstad 2023

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).高程数据可对地形与地表实现精细化刻画。该类数据可通过机载激光扫描（airborne laser scanning）构建点云（point clouds），或通过航空影像（aerial images）匹配生成点云。针对不同应用需求，点云的密度（单位：点/平方米）有所不同。基于此类点云，可生成栅格格式的数字地形模型（DTM, Digital Terrain Model）与数字地表模型（DOM, Digital Surface Model）。