为了提高大视场空间相机物距、投射角、地面像元分辨率、幅宽等几何参数的计算精度，研究了星下点成像与侧摆成像时上述几何参数的精确计算方法。在全面考虑地球曲率和投射角的基础上，建立了相应的几何模型，改进了大视场空间相机几何参数计算方法。根据仿真分析，对于轨道高度650 km、半视场40°的空间相机，当侧摆20°时，垂直线阵方向像元分辨率的最大值是最小值的2.31倍，是传统计算方法的1.78倍；平行线阵方向像元分辨率的最大值是最小值的7.16倍，是传统计算方法的4.29倍；幅宽是传统计算方法的1.33倍。因此，传统计算方法存在较大的误差，提出的精确计算方法对于提高大视场空间相机成像质量具有重要意义。

To precisely calculate geometric parameters of large field view space camera, such as object distance, projection angle, ground sampling distance, swath width, the precise calculation method of above-mentioned geometric parameters was studied，including nadir imaging and rolling imaging. Considering earth curvature and projection angle, geometric model was constructed, the calculation method was improved to heighten precision. The analysis shows that, for a large field of view space camera on 650 km orbit altitude, with 20° half field of view and 20° roll, the maximum GSDx is 2.31 times of the minimum GSDx, is 1.78 times of the approximate GSDx. The maximum GSDy will become 7.16 times the minimum GSDx, is 4.29 times of the approximate GSDy. The swath width is 1.33 times of the approximate swath width. Therefore, the traditional calculation method is inaccurate, the precise calculation method of geometric parameters in this paper is useful for the imaging quality.