大气信道对星地链路激光通信的影响

Influence of atmosphere turbulence on satellite to-ground laser communication link

星地链路激光通信系统的运行不可避免地要受到湍流大气等随机介质的影响,从而可导致卫星接收信息误码或通信中断。基于Born近似和弱起伏下的Rytov近似,分析推导了激光光束从发射机经湍流大气斜程到达接收机(或目标)时的光场变化。采用McGlamery算法,对Kolmogorov功率谱下的大气湍流随机相位屏进行了数值模拟,进而在模拟的相位屏和惠更斯-菲涅尔原理基础上,将主要适用于模拟平面波相位波前的McGlamery算法推广应用到了高斯光束的光场模拟。研究表明:大气信道段对星地链路激光通信系统有着极为重要的影响,也间接说明了McGlamery算法对准直激光光束相位波前模拟的适用性。

The laser communication link system between the ground station and the orbit satellite is inevitably subject to the atmospheric turbulence,which often leads to message error at receiver or communication interruption.Based on the Born approximation and the Rytov method,the characteristics of the light field on the receiver plane was derived when the laser beam propagated through the turbulent atmosphere by the slant path.At the same time,using the McGlamery algorithm,the atmosphere turbulence phase screen under the Kolmogorov power spectrum was numerically simulated.Based on the simulated phase screen and the Huygens-Fresnel principle,the McGlamery algorithm mainly used to simulate the phase screen of the plane wave was extended to the Gaussian beam propagation.Finally,it is concluded that the atmosphere turbulent channel has a significant impact on the satellite-to-ground laser communication link systems,and the result indirectly illustrates the McGlamery algorithm is valid to simulate the wave-front of Gauss beam.