Height data Yellow 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). 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描述。该类数据可通过机载激光扫描（airborne laser scanning）生成点云，或通过航空影像匹配得到点云；针对不同应用需求，点云的密度（单位：点/平方米）存在差异。基于上述点云，可生成格网格式的地形数字模型（DTM, Digital Terrain Model）与地表数字模型（DOM, Digital Surface Model）。