宽视场遥感相机像移速度模型及补偿策略

Image Motion Velocity Model and Compensation Strategy of Wide-Field Remote Sensing Camera

  • 摘要: 宽视场遥感相机在轨成像期间,受地球自转、卫星颤振、姿态机动等因素影响而产生像移,导致成像质量降低。为此,提出了一种适用于宽视场遥感相机的像移速度模型,并考虑了离轴角对计算精度的影响,推导了离轴三反相机像移速度和偏流角解析式。以某卫星为例,仿真分析了3种典型成像模式下像移速度和偏流角在焦面的分布情况,仿真结果与定性分析结果一致,验证了像移速度模型的正确性。在此基础上,针对侧摆兼具俯仰成像模式,提出了相应的像移补偿策略。补偿效果表明,卫星侧摆35°兼具俯仰35°成像时,采用全局优化偏流角匹配策略能保证整个焦面区域的调制传递函数(modulation transfer function,MTF)均大于0.95(16级);采用局部优化偏流角匹配策略能保证焦面重点观测目标的MTF大于0.95(96级);采用提出的像移速度匹配策略在分11组调节行周期情况下,能保证整个焦面区域的MTF均大于0.95(16级)。仿真结果表明,提出的像移补偿策略能有效解决侧摆兼具俯仰成像时的像质下降问题,可为宽视场遥感相机像移补偿提供可靠依据。

     

    Abstract: During the orbit imaging of the wide-field remote sensing camera, it is affected by the earth's rotation, satellite jittering, attitude maneuverings and other factors, resulting in a decrease in image quality. Therefore a image motion velocity modeling is put forword, which is suitable for the wide-field of the remote sensing camera and considers the effect of off-axis angle on the calculation accuracy, to deduce the off-axis three-mirror camera image motion velocity and drift angle. Taking a satellite as an example, the distribution of the image motion velocity and the drift angle in the focal plane of the three typical imaging modes is simulated. The simulation results, which are consistent with the qualitative analysis results, verify the validity of the image motion velocity model. On this basis, a corresponding image motion compensation strategy is proposed against the scroll and pitch imaging mode. The compensation effect shows that, when the satellite is imaging as scrolling and pitching angles are both 35°, the global optimization drift angle matching strategy can guarantee that the MTF of the whole focal area is greater than 0.95 (16 integration stages). The MTF of the focus observation target is greater than 0.95 (96 integration stages) with the local optimization drift angle matching strategy. Using the proposed method of image motion velocity matching strategy, the MTF of the whole focal area is greater than 0.95 (16 integration stages) when dividing the row cycles into 11 groups. The simulation results show that the proposed strategy can effectively solve the image quality degradation problem when scroll and pitch imaging and can provide a reliable basis for the image motion compensation of the wide-field remote sensing camera.

     

/

返回文章
返回