特殊函数在湍流大气传输光束漂移中的应用

研究特殊函数在激光湍流大气传输光束漂移效应中的应用，为提高跟瞄系统的瞄准精度提供理论依据。基于特殊函数和修正Von Karman谱，对斜程湍流大气传输光束漂移方差表达式进行了数值仿真。数值模拟表明，特殊函数高次项的近似舍去对激光湍流大气传输光束指向精度影响甚微。在外尺度较小时,光束漂移方差变化较快；随着外尺度的增加，光束漂移增加缓慢且趋于饱和。在相同的外尺度下，发射孔径（初始光束束径）与发射天顶角的增大对光束漂移具有抑制作用，且天顶角接近π/2，光束漂移角方差快速减小。

Special functions for beam drift in atmospheric turbulence

In order to improve the sighting accuracy of a tracking and sighting system, the application of special functions in laser beam drift occurred in atmospheric turbulence was studied. Based on special functions and modified Von Karman spectrum, some expressions are derived for the variance of the beam drift in the slant path. Numerical simulation shows that neglecting the higher-order terms of the special function will not significantly reduce the laser beam pointing accuracy for a long-distance transmission. When the outer scale of turbulence L0 is rather small, the outer scale of the turbulence has great effect on beam wander. When L0 increases, the variance of the beam wander will increase slowly and approach saturation. In the same outer scale of turbulence, the increase in transmitting aperture (original beam width)and transmitting zenith angle will prevents beam from drifting. Especially, the variance of the beam drift decreases rapidly when zenith angle is close to π/2. Numerical simulation shows the above results are useful for improving the accuracy of the tracking and sighting system.