摘要
针对用运动补偿增加成像光谱仪能量积分时间的情况,推导出了其地面分辨率和望远系统焦距选择的一般表达式。运动补偿成像光谱仪地面分辨率与指向反射镜转角成反比关系,转角大时地面分辨率低,反之亦然。给定成像光谱仪探测器像元尺寸为20μm,飞行轨道高度为600 km,光线摆角≤30°,以星下点、最大摆角和整个运动补偿段地面分辨率中值为30 m为依据来计算望远系统的焦距,求得望远系统焦距为400、470、435 mm,并给出了此时的地面分辨率相对比值与光线摆角的关系曲线。对于积分时间一定的情况,推导出指向反射镜的反扫角速度公式。结果表明:指向反射镜反扫角速度是卫星运动速度、飞行轨道高度、对目标进行凝视测量时光线的提前摆角、飞行时间及地球半径的函数,改变指向反射镜反扫的角速度,可使积分时间增大N倍。
The general expressions of the ground resolution and the telescope focal length for an imaging spectrometer were deduced to investigate the increase of energy integral time with motion compensation. The ground resolution is inverse proportion to the pointing angle for the imaging spectrometer with the motion compensation. It will decrease when the pointing angle increases, and vice versa. By giving a pixel size of 20 μm for a detector,an orbit altitude of 600 km and a beam deflexion angle low than 30° for the imaging spectrometer, the effective focal length of the telescope was calculated （400,470 or 435 mm）, and the relation curves between the relative ratios of ground resolution and the beam deflexions were presented. On the situation of certain integral time, the expression of anti-scanning angular velocity of the pointing mirror was deduced. The result indicates that the anti-scanning angular velocity of the pointing mirror is the functions of the velocity of secondary planet, orbit altitude, the beam deflexion angle ahead of schedule on gazing an object, aviation time and the radius of the earth. The integral time will increase by N times when anti-scanning angular velocity of the pointing mirror is changed.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2009年第4期745-749,共5页
Optics and Precision Engineering
基金
国家自然科学基金资助项目(No.60538020)
关键词
成像光谱仪
望远系统
运动补偿
指向反射镜
地面分辨率
imaging spectrometer
telescope
motion compensation
pointing mirror
ground resolution
