空间光通信需要苛刻的功率预算, 由于实际大气信道特性非常复杂, 采用一般链路方程对大气信道功率进行预算往往会引进较大误差。通过对大气衰减效应、湍流效应、折射效应等影响大气信道特性的因素进行综合分析, 结合大量的理论推导和计算, 提出了一种对链路方程的修正方法, 得到了一个能够积极反应信道特性的链路方程。采用修正后的链路方程, 在通信距离为6 km, 误码率优于10-8的光通信实验中进行了功率预算。实验与分析表明, 该链路方程修正方法具有合理性, 功率预算和实验结果基本相符, 近地光通信对星地光通信具有等效验证性。

Space optical communication demands harsh power budgets. Since the actual channel characteristics of the atmosphere is very complex, the channel power budgets tends to introduce large deviation with the general link equation. By the comprehensive analysis of the factors of effecting characteristics of atmospheric channel, such as atmospheric attenuation, turbulence effects and refraction, etc. Combined with a large number of the derivation and calculation, a correction method of the link equation is put forward to get a link equation that positively responds to the channel characteristics. By this equation, budgets optical power for the actual ground optical communications with the link distance of about 6 km and the bit error better than 10-8. Experiments and analysis show that the link equation correction method is reasonable, the power budget is consistent with experimental results, and the near ground optical communication is equivalent demonstration to satellite-ground optical communication.