Geometric Accuracy Evaluation of GF-7 Image

We selected a scene of “GF-7” satellite multispectral rear-view camera image in Chengdu, Sichuan Province of China. At the same time, we take 26 high-precision GPS sampling points evenly distributed in the region as control points, and make statistics on the geometric positioning accuracy of images. The experimental results show that the horizontal error without control points is 264.56 m and the median error is 3.74 m; Adding control points has an obvious effect on correcting the horizontal error of the image. When five control points are used for geometric correction, the average horizontal error is 4.76 m and the median error is 2.70 m. When the number of ground control points is more than five, the imaging accuracy of GF-7 meets the accuracy requirements of 1: 10 000 scale map.