机载全天时星敏感器参数设计及实验

为了提供机载全天时星敏感器参数设计方法，从光电探测信噪比公式出发，结合Modtran软件中天空亮度数据，推导了适用于星体目标探测的信噪比计算公式，并以探测3.5等、4等、4.5等星为例，重点研究了通光口径、系统F数、曝光时间与探测信噪比之间的变化规律，并给出机载全天时星敏感器相应参数的设计方法。为验证设计方法的正确性，设计了地面原理实验，选择以北极星（视星等2.02等）为探测目标，设计了通光口径83 mm、焦距1 500 mm的全天时星敏感器原理样机，通过地面观测实验，在天空辐射最强时刻对北极星的探测信噪比为6.84 dB，满足理论计算的6 dB指标需求，验证了设计方法的正确性。

Parameter design and test of airborne all-day star sensor

In order to provide parameters design method of airborne all-day star sensor, in this paper, the SNR(Signal to Noise Ratio) computation formula for star targets detection was derived according to the SNR formula of optical-electric detection system and sky radiance data from Modtran software. The relation between detection SNR and diameter, F number,exposure time was researched for the stars of visual magnitude of 3.5,4,4.5, and the corresponding parameters design method of airborne all-day star sensor was given. In order to verify the correctness of the design method, the ground-based observation test was carried out. Polaris(Mv2.02) was selected as target, and the all-day star sensor prototype with 83 mm diameter, 1 500 mm focal length was designed. Through the ground-based observation test, at the most powerful sky radiation moment the SNR for detection Polaris was 6.84 dB, met the minimum detection requirements 6 dB from the theoretical calculation. The correctness of the design method is verified.