论文部分内容阅读
大视场空间相机在轨成像期间,由于地球自转、卫星姿态机动和颤振等因素导致焦面像速场呈非线性各向异性分布。为此提出了一种新的基于刚体运动学的像移速度场建模方法,考虑离轴角参数,推导了离轴三反大视场空间相机的像速场解析式。以某大视场空间相机为例,分析了侧摆成像时同速与异速像移速度匹配模式对相机成像质量的影响。分析结果表明:以传函下降5%为约束,侧摆15°成像时,当积分级数大于10级时应采用异速匹配模式,积分级数为32级时,异速匹配相比于同速匹配使焦面动态MTF从0.340 8提高到0.970 2。当积分级数确定为16级时,侧摆角在12.3°以内时可采用同速匹配模式。在轨成像结果证明了像移速度场模型的准确性,可为大视场空间相机像移补偿提供可靠依据。
Large field space camera in-orbit imaging, due to the Earth’s rotation, satellite attitude maneuvering and flutter and other factors led to focal plane image velocity field was nonlinearly anisotropic distribution. A new modeling method of image velocity field based on rigid body kinematics is proposed in this paper. Considering the parameters of off-axis angle, the analytical solution of the image velocity field is derived. Taking a large field space camera as an example, the influence of the matching modes of the same speed and different speed on the imaging quality of the camera is analyzed. The analysis results show that when the number of integral stages is greater than 10, the allometric speed matching mode should be adopted when the 5% reduction of the letter of transmission is the constraint and the 15 ° imaging is carried out. When the number of integral stages is 32, The speed matching increases the dynamic MTF of the focal plane from 0.340 8 to 0.970 2. When the integral series is determined to be 16, the same speed matching mode can be adopted when the roll angle is within 12.3 °. The in-orbit imaging results demonstrate the accuracy of the image velocity field model and provide a reliable basis for imaging compensation of large-field space cameras.