基于扫描反射镜的航空相机前向像移补偿

The Forward Image Motion Compensating Scheme of Aerial Camera Based on Scanning Mirror

航空相机航向方向的像移包括飞机前向飞行引起的前向像移以及飞机姿态(俯仰/偏航)在航向方向的分量。本文以某摆扫型航空相机为例,分析了利用扫描反射镜进行前向方向像移补偿的原理,扫描反射镜以二分之一的前向方向像移角速度的速度旋转即可补偿前向像移。文中探讨了两种控制方案,第一种方案将陀螺直接安装在反射镜上,结构设计简单,但控制电路较复杂,且需增加一个陀螺;第二种方案提出利用机械系统增加2:1速比的方法,可以节省成本,且不增加控制系统的难度。经过实际工程实践证明,第二种方案简单实用,可以满足相机补偿要求。

The forward image motion of the aerial camera in the direction of the aircraft flight includes the forward image motion caused by aircraft flying and the component of the posture changing （pitching/yawing） in this direction. The forward image motion compensation principle of the whisk broom aerial camera by utilizing scanning mirror is analyzed. Two kinds of control schemes are discussed in this paper. In the first option, the gyro is installed directly at the mirror, so mechanical designing is simple, but the control circuit is more complex, and another gyro is needed. And the second method is put forward which increase the 2：1 ratio by the mechanical systems. The project can save cost, without increasing the difficulty of the control system. It is proved that the project is uncomplicated, practical, and can meet the camera compensation requirements.