为了能够通过水平大气能见度判断可实现的最大通信速率,基于Mie散射理论和脉冲多路径效应,建立了通信速率与水平大气能见度的数学模型;通过蒙特卡罗仿真,得到了800 nm和1550 nm波段的气溶胶散射粒子的散射参数,给出了2~25 km水平大气能见度下两个波段产生的脉冲展宽曲线,分析了初始脉宽、脉冲位置调制元数、水平大气能见度对最大通信速率的影响。结果表明,1550 nm波段具有更好的通信效果;随着水平能见度的提高,可实现的最大通信速率也在提高,且在良好的水平能见度下选择小的初始脉宽和较低元的脉冲位置调制,能最大程度地提高深空激光通信速率。

A mathematical model is established by the Mie scattering theory and the pulse multipath effect to predict the maximum communication rate based on the horizontal atmospheric visibility. With the method of Monte Carlo simulation, we obtain the scattering functions of the aerosol scattering particles at 800 nm and 1550 nm, respectively, and the pulse broadening curves of the two wavebands in the visibilities of 2-25 km. The influence of the initial pulse width, the pulse position modulation (PPM) element and the horizontal visibility on the communication rate is analyzed. Results show that the communication effect is better in 1550 nm band and the maximum communication rate improves with the increasing visibility. Under the good visibility, the small initial pulse width and PPM element can maximize the communication rate.