凝视模式下的画幅相机两轴像移补偿

通过斜视画幅相机的几何模型,选择载机相关坐标系,建立了计算目标航迹速度到像面坐标系下像移速度的数学模型。通过坐标变换将航迹速度(目标在航迹坐标系下的速度)转换至机体坐标系下的速度矢量,最终至补偿坐标系下的运动矢量;计算视轴长度,得到了扫描镜补偿角速度。最后,阐述了像面旋转机构在像移补偿中的作用,并给出了具体位置角计算公式。提出的采用扫描镜和像面旋转机构相结合的方案实现了凝视工作模式下的画幅相机像移补偿,利用坐标变换计算出的相应量,可为将来画幅相机在该模式下的像移补偿工程应用提供必要的参考。

Attitude compensation of frame aerial camera based on spot mode

The spot mode is one of the operation methods used in frame aerial cameras. The mode can point at interest objects via rotating scan mirror in position angle and depression angle directions and can view objects from different directions. In this paper,the geometrical model of a camera is presented and the relative coordinate axes are chosen. Then, a mathematical model for computing the image velocity from track coordinate system to image plane coordinate system is established. To compute the compensation velocity,the object velocities under aircraft coordinate axes and the velocities under compensation coordinate axes are computed and the visual axis length is also calculated,then the compensation angle velocity is obtained. Finally, the image plane revolution mechanism's function is explained in detail. The scan mirror and image plane revolution mechanism are incorporated in frame attitude compensation method based on spot mode. The numerical values calculated by coordinate conversion will provide the references for IMC engineering application.