GF-4卫星不同成像状态下影像定位误差特性分析

高分四号（GF-4）卫星作为我国高分对地观测系统中一颗高分辨率面阵成像的静止轨道卫星，其在不同成像状态下的影像几何定位精度一直是科研人员和应用部门所关注的。本文以谷歌地球数据为几何参考，通过对比GF-4卫星影像和谷歌地球影像上同名点位置信息，分析了GF-4卫星在凝视、俯仰、滚动成像状态下的影像定位特性。结果表明，单幅影像内部均出现了明显的系统误差，凝视成像过程中同一点位的影像定位误差波动较小，俯仰/滚动姿态影像定位误差与俯仰角/滚动角成正比关系。该结论可为地面数据处理部门和用户在数据校正和应用时提供参考。

Geo-positioning error characteristic analysis of GF-4 imagery under different imaging states

As a geostationary orbit satellite with high-resolution array imaging characteristic in the Chinese high-resolution earth observation system, the geo-positioning accuracy of GF-4 images under different imaging states has always been the concern of researchers and application departments. In this paper, the geo-positioning accuracy of GF-4 images under staring, pitching and rolling imaging states is analyzed by comparing the location information of the same points on GF-4 images with that on Google Earth images. The results show that there are obvious system errors in a single image. The image geo-positioning errors at the same point in staring imaging state are almost the same. The image geo-positioning errors under the pitch and rolling attitudes are proportional to the pitch and rolling angles. The conclusion can provide the data correction and application reference information to the ground data processing department and users.