白天恒星探测最大的困难在于过强的背景辐射, 全天时近红外多视场探测系统将三个参数相同的探测器刚性固连在探测平台上, 同时进行恒星探测。结合中国地理位置, 分析了白天近红外波段三个探测视场内的恒星——背景对比度随太阳天顶角、平台方位角、平台x方向俯仰角, 平台y方向俯仰角及平台高度的变化情况。结果表明, 随太阳天顶角的变化, 对比度近似指数增长; 随平台方位角的变化, 对比度呈正态分布变化; 当平台有一定的倾角时, 对比度变化都很低且变化范围不大, 但三个视场间相差较大(相差1.5~20倍不等); 随着平台高度的变化, 对比度呈指数变化明显增大; 为星等修正研究奠定较好的基础。

The main difficulty of star detection during daytime is the over strong background radiation. Detectors with three same parameters are rigid connected to the detection platform by an all-weather near Infrared multi-FOV detection system to detect stars. According to geographical positions in China, star background contrast during daytime at near Infrared band in three detection FOV changing with sun zenith, platform azimuth, pitching angle in x and y direction as well as platform height is analyzed. The results show that with the variation of sun zenith, contrast similar exponent increases. With the variation of platform azimuth, the contrast approaches to normal distribution. When the platform has a certain pitching angle, the contrast changes little and change range is small, but three FOV has a big difference such as from 1.5 to 20 times. The contrast will exponentially increase greatly with the platform height changing to provide a better basis for star magnitude amendment.