中强大气湍流信道中激光传输数值仿真精度的研究

Research on the accuracy of numerical simulation of laser propagation in moderate-strong atmospheric turbulence channel

在激光湍流传输仿真中,随着路径上湍流的不断增强,光斑会产生巨大的畸变,往往无法同时具备较高的仿真精度和计算效率。提出了在仿真过程中采用不同的收发平面采样网格间距的方法,实现了中强湍流信道中的激光传输仿真。该方法可以在保持采样点数不变的情况下,根据具体情况设置不同的收发平面网格间距,使得激光传输的仿真结果在不同湍流强度下都与理论值更加接近。仿真结果表明:减小发射平面网格间距之后,闪烁指数仿真值相对误差从20%以上降低到10%以内,最低可达4.15%,波动标准差也从0.07以上减小到0.05以内,最小可达0.015。

In the simulation of laser turbulence propagation, with the continuous enhancement of turbulence along the path, the light spot will produce huge distortion, and it is often impossible to have high simulation accuracy and computational efficiency at the same time. In this paper, a method is proposed to simulate the laser propagation in moderate-strong turbulence channel by adopting different sampling mesh spacing in the transmitting and receiving plane. This method can be used to set up different mesh spacing between the transmitting and receiving planes according to the specific situation while keeping the number of sampling points unchanged, to make the simulation results of laser propagation closer to the theoretical value at various turbulence intensities. The simulation results show that, after the mesh spacing of transmitting plane is reduced, the relative error of scintillation index simulation value decreases from more than 20% to less than 10%, and the minimum error reaches 4.15%.The standard deviation of scintillation index simulation value also decreases from more than 0.07 to less than 0.05, and the minimum error reaches 0.015.