摘要
高分辨率空间相机采用侧摆摄影模式来提高时间分辨率,而地球椭球等因素会使空间相机在侧摆摄影时不同视场位置的像移速度和偏流角不同。针对这一问题,推导了基于地球椭球的空间相机在侧摆摄影时不同视场位置的像移速度和偏流角计算公式。以某立体测绘卫星上携带的高分辨率相机为例,分析了侧摆摄影时统一和分片调整行周期与偏流角对调制传递函数的影响。分析和在轨测试实验表明,以传递函数下降5%为约束,侧摆10°摄影时,若积分级数大于22级,则应分片调整行周期。和统一调整行周期相比,积分级数为32级时,分片调整行周期沿轨方向的传递函数下降从10.28%减少到0.11%。而积分级数固定为16级时,统一调整行周期时的侧摆角不应超过13.2°。
The scroll imaging of a space camera can improve its temporal resolution.However,the space camera shows different image motion speeds and drift angles at different positions of field of view in the scroll imaging because of the earth ellipsoid and varied scroll angles.To overcome the problem,the formulas of image motion speeds and drift angles at different positions of field of view were deduced for the scroll imaging based on earth ellipsoid.By taking a high resolution space camera carried on a stereoscopic mapping satellite for an example,the influence of row transfer periods and drift angles adjusting uniformly and individually on Modulation Transfer Function（MTF） was analyzed.Analysis results and on-orbit testing experiments under a constraint of 5% drop for the MTF indicate that the row transfer periods should be adjusted individually if the integral stages are more than 22 in scroll imaging with scroll angle of 10°. In comparison to adjusting row transfer periods uni formly,the drop of MTF along the track direction would be cut down from 10.28% to 0.11% by adjusting row transfer periods individually.If integral stages are fixed to 16,the scroll angle by adjusring row transfer periods uniformly should not be over 13.2°.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2014年第2期351-359,共9页
Optics and Precision Engineering
基金
国家自然科学基金资助项目(No.61108066)
吉林省科技发展计划资助项目(No.20130101028jc)
关键词
空间相机
侧摆摄影
像移
地球椭球
调制传递函数
space camera
scroll imaging
image motion
earth ellipsoid
Modulation Transfer Function（MTF）
