通常采用离轴抛物面镜来对双波段成像光学系统的光轴进行校准以便实现两个成像系统的像素级图像融合,但抛物面镜和点光源安装时所产生的误差会影响两个光轴的校准精度。根据几何关系及光学成像原理,推导了离轴抛物面镜对焦点附近点光源的成像公式,在此基础上分析了抛物面镜和点光源的安装误差对双波段成像光学系统光轴校正造成的影响。根据推导的误差分析公式可将可见光通道和红外通道双波段光轴的平行性误差控制在1个像素以内。

To achieve pixel level image fusion of the dual band optical imaging system, the optical axis of the two imaging systems with the help of off-axis parabolical mirror is usually caliberated. However, the error caused by installation of the parabolical mirror and the point source will influence the precision of optical axis calibration. According to the geometric relation and optical imaging principle, the imaging formula of spotlight that around the off-axis parabolic mirror focus is deduced in this paper. The influence on axis calibration of the dual band optical imaging system, which caused by the installing error of parabolical mirror and point source is analyzed. Based on the formula of error analysis deduced by this paper, visible and infrared dual band optical axis parallelism error can be controlled within one pixel.