Photo: Ringebu-Øyer 1974

Orthophoto has the same geometric properties as a map and can be linked to a reference system. Orthophotos are divided into different orthophoto standards suitable for different purposes. Photo by Ortho: Covers areas that mainly consist of dense and scattered settlements and agricultural areas. Ground resolution is usually > 0.15 – 0.25 m. Accuracy ± 0.50 m.正射影像（Orthophoto）具备与地图一致的几何特性，且可与参考坐标系关联。 正射影像可依据不同应用需求划分为多种适配的标准类型。 Ortho类正射影像： 覆盖区域以密集且零散的聚落与农业用地为主。 地面分辨率通常为0.15~0.25米，精度为±0.50米。