Image motion compensation of off-axis two-line camera based on earth ellipsoid
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摘要: 离轴反射式双线阵立体测绘相机的视轴和光轴分离，由于地球为椭球体，视轴和光轴对应的地物点的距离随星下点与升交点的地心角而变化。而成像传感器与光轴垂直，对视轴对应的地物点成像，这些因素导致离轴反射式双线阵立体测绘相机的像移速度和偏流角随离轴角等变化。在对离轴反射式空间相机的成像原理进行分析的基础上建立其等效简化模型，推导了基于地球椭球的离轴反射式双线阵立体测绘相机的像移速度和偏流角计算公式。并以某离轴反射式双线阵立体测绘相机为例，对正视相机和后视相机统一调整行周期与偏流角对成像质量的影响进行分析。分析结果表明，以调制传递函数下降不超过5%为约束，当积分级数大于4 时应分别调整正视相机和后视相机的行周期。统一调整偏流角时应以正视相机和后视相机偏流角的均值为准，积分级数应取89 以内。Abstract: As view axis and optical axis of reflective off-axis two-line stereo mapping camera are separate and the earth is in fact an ellipsoid, distances between objects on earth corresponding to view axis and optical axis vary with geocentric angle from substellar to ascend point. In addition imaging sensor is perpendicular to optical axis while imaging the objects on earth corresponding to view axis. All these factors lead to change of image motion speeds and drift angles along with off-axis angles. Equivalent simplified model of reflective off-axis space camera was established based on analysis of its imaging principle. Formulas of image motion speeds and drift angles of reflective off-axis two-line stereo mapping camera based on earth ellipsoid were deduced. Influence of adjusting row transfer periods and drift angles uniformly on imaging quality of a reflective off-axis two-line stereo mapping camera was analyzed. Results of analysis indicates that if no more than 5% drop of modulation transfer function is used as a constraint, row transfer periods of nadir-view camera and backward-view camera should be adjusted individually as TDI stages is greater than 4. When drift angles are adjusted uniformly, mean value of drift angles of nadir-view camera and backward-view camera should be used and TDI stages should not exceed 89.
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Key words:
- earth ellipsoid /
- off-axis /
- two-line /
- image motion /
- MTF
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[1] [2] Wang Meiqin, He Zhonghou, Bai Jiaguang. Optical design of off-axis three-mirror anastigmatic system for imaging spectrometer [J]. Infrared and Laser Engineering, 2012, 41 (1): 167-172. (in Chinese) 王美钦, 王忠厚, 白加光. 成像光谱仪的离轴反射式光学 系统设计[J]. 红外与激光工程, 2012, 41(1): 167-172. [3] [4] Xue Donglin, Zheng Ligong, Zhang Feng. Off-axis three- mirror system based on freeform mirror [J]. Opt Precision Eng, 2011, 19(12): 2813-2820.(in Chinese) 薛栋林, 郑立功, 张峰. 基于光学自由曲面的离轴三反光 学系统[J]. 光学精密工程, 2011, 19(12): 2813-2820. [5] Yan Peipei, Fan Xuewu. New design of an off-axis reflective zoom optical system [J]. Infrared and Laser Engineering, 2012, 41(6): 1581-1586. (in Chinese) 闫佩佩, 樊学武. 新型离轴反射式变焦光学系统设计[J]. 红外与激光工程, 2012, 41(6): 1581-1586. [6] [7] [8] Niu Rui, Wang Yu, Wang Jianrong. Prediction and simulation of location performance of spaceborne two-line array camera[J]. Journal of Geomatics Science and Technology, 2011, 28(5): 351-355. (in Chinese) 牛瑞, 王昱, 王建荣. 航天双线阵相机无控定位性能预测 与仿真[J]. 测绘科学技术学报, 2011, 28(5): 351-355. [9] [10] Wu Guodong. Calibration of inner orientation parameters and distortion for three-mirror off-axis TDICCD camera [J]. Opt Precision Eng, 2012, 20(3): 462-467. (in Chinese) 吴国栋. 离轴三反时间延迟积分CCD 相机内方位元素和 畸变的标定[J]. 光学精密工程, 2012, 20(3): 462-467. [11] Wang Jiaqi, Yu Ping, Yan Changxiang, et al. Space optical remote sensor image motion velocity vector computational modeling [J]. Acta Optica Sinica, 2004, 24(12): 1585-1589. (in Chinese) 王家骐, 于平, 颜昌祥, 等. 航天光学遥感器像移速度矢计 算数学模型[J].光学学报, 2004, 24(12): 1585-1589. [12] [13] [14] Wu Xingxing, Liu Jinguo. Image motion compensation of three-line stereo mapping camera using earth ellipsoid [J]. Opt Precision Eng, 2011(8): 1793-1800. (in Chinese) 武星星, 刘金国. 应用地球椭球的三线阵立体测绘相机像 移补偿[J]. 光学精密工程, 2011(8): 1793-1800. [15] Xie Shaobo, Zhou Weimin, Zhang Wei. Calculation and control for deviant angle of TMA camera on satellite [J]. Aerospace Shanghai, 2012, 29(1): 19-22. (in Chinese) 谢少波, 周伟敏, 张嵬. 离轴三反(TMA) 相机在轨成像的 偏流角计算与控制[J]. 上海航天, 2012, 29(1): 19-22. [16] [17] [18] Li Xiaoyun, Du Wei. Analysis of image motion effect on satellite TDICCD camera image quality [J]. Spacecraft Engineering, 2011, 20(3): 51-55. (in Chinese) 李晓云, 杜伟. 星载TDICCD 相机像移对成像质量的影响 分析[J]. 航天器工程, 2011, 20(3): 51-55. [19] Li Weixiong, Yan Dejie, Wang Dong. Image motion compensation method of high resolution space camera's imaging with pitch angle [J]. Infrared and Laser Engineering, 2013, 42(9): 2442-2448. (in Chinese) 李伟雄, 闫得杰, 王栋. 高分辨率空间相机俯仰成像的像移 补偿方法[J]. 红外与激光工程, 2013, 42(9): 2442-2448. [20] [21] Wong H S, Yao Y L, Schlig E S. TDI Charge-coupled devices: design and applications[J]. Journal of Research and Development, 1992, 36(1): 83-105. -
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