光学 精密工程, 2014, 22 (3): 806, 网络出版: 2014-04-24
离轴三反航天测绘相机像移对成像质量的影响
Influence of image motion on image quality of off-axis TMA aerospace mapping camera
离轴三反系统 航天测绘相机 像移 偏流角 地球曲率 像质 off-axis Three Mirror Anastigmat(TMA)system aerospace mapping camera image motion drift angle earth curvature image quality
摘要
对离轴三反测绘相机的像移模型进行了必要的修正以获得高的测绘精度。对两线阵离轴三反航天测绘相机进行建模, 推导了考虑地球曲率的斜视和后视相机的像移速度和偏流角计算公式。以交会角为25°的离轴三反航天测绘相机为例, 分析了斜视相机以正视为准调整行周期和偏流角, 以及兼顾正视、斜视相机调整偏流角时, 像移速度匹配残差和偏流角调整残差对图像质量的影响。分析结果表明, 以调制传递函数下降5%为约束,当积分级数大于5时, 应分别调整斜视和正视相机的行周期; 按正视相机调整斜视相机的偏流角时, 积分级数应取71以内; 若兼顾正视、斜视相机调整偏流角, 当积分级数为96时, 对正视、斜视相机的成像质量无本质影响。
Abstract
This paper explores a method to correct the image movement model of an off-axis Three-mirror Anastigmat(TMA) optical system to obtain higher mapping accuracy. Two kinds of line-array Off-axis TMA mapping cameras were modeled and the calculation formulas of image motion speeds and drift angles for the oblique-view camera and the nadir-view camera were deduced by considering earth curvature. By taking the off-axis TMA aerospace mapping camera with an intersection angle of 25° for an example, the influences of image motion speed matching remains and drift angle remains on the image quality of off-axis TMA aerospace mapping camera were analyzed at the oblique-view camera adjusted with the row transfer periods and their drift angles. Results indicate if more 5 TDI stages are used, the oblique-view camera and the nadir-view camera under a constraint of 5% MTF reduction should adjust their row transfer periods respectively; if drift angle of the oblique-view camera is adjusted according to the nadir-view camera, TDI stages should be no more than 71. However, If drift angles are adjusted by giving attention to the oblique-view camera and the nadir-view camera, the imaging quality for the both cameras has no essential influence at a TDI stage of 96.
王国良, 刘金国, 龙科慧, 周磊, 郭疆, 陈佳豫, 余达, 孔德柱. 离轴三反航天测绘相机像移对成像质量的影响[J]. 光学 精密工程, 2014, 22(3): 806. WANG Guo-liang, LIU Jin-guo, LONG Ke-hui, ZHOU Lei, GUO Jiang, CHEN Jia-yu, YU Da, KONG De-zhu. Influence of image motion on image quality of off-axis TMA aerospace mapping camera[J]. Optics and Precision Engineering, 2014, 22(3): 806.