三反射系统航空遥感器像旋转分析  

Analysis of Image Rotation for Aerial Remote Sensor with Three-Mirror Reflective Optical System

作　　者：于春风[1,2] 丁亚林[1] 惠守文[1] 张景国[1] 陈伟[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院研究生院,北京100049

出　　处：《光学学报》2011年第8期262-268,共7页Acta Optica Sinica

基　　金：国家863计划(2006AA06A208)资助课题

摘　　要：像旋转是影响和限制成像质量的一个重要因素。像面反射镜不随扫描反射镜同步旋转时,就会在焦平面上产生像旋转,导致地面信息丢失和图像分辨率明显下降。为了提高航空遥感相机的动态分辨率,必须对遥感相机进行像旋转分析。根据光反射矢量理论,对具有三反射光学系统的航空遥感器的成像特性进行研究。将整个遥感相机抽象为一个简单数学模型。在笛卡儿坐标系中,通过数学坐标变换的方法,对扫描反射镜沿俯角和位角方向的旋转对像质产生的影响做定量分析。扫描反射镜沿俯角方向旋转引起像旋转,沿位角方向旋转可以对前向像移进行补偿。通过分析,为设计一种对偏流角进行补偿的机构以及控制时间延时积分(TDI)CCD的积分时间提供理论依据。结果表明,该方法的同步旋转误差小于1/3pixel,能够获得优质图像,从而提高整个系统的传递函数。Image rotation is one important aspect on influence and confinement of image quality. The image mirror non-synchronous rotation with scanning mirror will cause image rotation in the focal plane. Consequently, it will lead to the loss of ground information and the image resolution will decrease significantly. In order to improve the dynamic state resolution of aerial remote sensor, it is indispensable to analyze the image rotation of aerial remote sensor. According to the optical reflection vector theory, imaging characteristics of aerial remote sensor with three-mirror reflective optical system are studied. At first, a simple mathematic model is abstracted from the aerial remote sensor. In the Cartesian coordinate system, it can analyze the influence on image quality which is caused by scanning mirror rotation along the direction of position angle and plunge angle by the mathematic method of coordinate transformation. Scanning mirror rotations along directions of plunge and position angles produce image rotation and image motion, respectively. It will provide a theoretical basis for designing a mechanical structure to compensate for drift angle and for the control of integration time of time delayed and integration （TDI） CCD according to the analysis. Test results show that the rotation synchronous error is less than one-third of pixel size and that prime images can be acquired without any blurring. Thereby, the modulation transfer function （MTF） of optical system can be improved.

关 键 词：航空成像 像旋转 遥感器 三反射系统 笛卡儿坐标系 偏流补偿机构 

分 类 号：O436[机械工程—光学工程]