上下行传输孔径接收光强起伏特性分析

 为了研究地星上行和星地下行激光链路孔径内接收光强信号的典型特征，基于大气湍流理论和位相屏方法，计算了短波和中波红外激光在特定大气相干长度条件下，孔径内接收激光功率与总功率的比值及起伏情况。根据统计结果讨论了上下行大气通道传播特性的差异，结果表明相同外界条件下，直径50 cm孔径内接收的下行激光信号强度大于上行激光信号强度1个数量级以上，其信号的起伏程度也低于上行激光；中等湍流下，下行激光孔径接收光强的概率分布函数服从对数正态分布，最大概率接收功率比与无湍流条件下的功率比值一致，分别为0.42%(1.315 μm)和 0.26%(3.8 μm)。

Analysis of irradiance scintillation for uplink and downlink propagation and aperture receiving

In order to study the typical character of receiving light intensity signal in ground-to-satellite/satellite-to-ground short-infrared and medium-infrared laser propagation, based on atmospheric turbulence theory and phase screen method, the scintillation of power ratio in the receiving aperture was calculated under the condition of specific atmospheric coherent length. According to the statistical results, the difference of uplink and downlink atmospheric channel was discussed. The results show that the receiving signal intensity of downlink channel is one order of magnitude greater than that of uplink channel and the signal scintillation level of downlink channel is lower than that of uplink channel. Under the condition of moderate atmospheric turbulence, the receiving light intensity probability distribution function of downlink channel is logarithmic normal distribution, and the maximum probability point is corresponding to that under no turbulence condition, the maximum probability receiving light intensity of short-infrared and medium-infrared laser are 0.42%(1.315 μm) and 0.26%(3.8 μm),respectively.