基于SPGD算法的激光大气传输湍流效应校正的初步研究

Elementary Study on Turbulence Effects Resulted from Laser Propagation in the Atmosphere Based on the Stochastic Parallel Gradient Descent Algorithm

随机并行梯度下降算法(SPGD)是近年来广泛发展的一种无模型优化控制算法,它具有速度快、无需信标光等优点,得以运用于自适应光学系统中。利用相位屏法数值模拟激光大气传输过程,以61单元变形镜为校正器,采用SPGD算法对激光大气传输湍流效应进行了初步校正研究,研究表明:SPGD算法可以用在自适应光学系统中用于校正激光大气传输湍流效应引起的畸变,且不同参数如扰动幅度值、增益系数的选取对校正效果有一定影响,文中给出了不同传输情况下的仿真计算结果。

Stochastic parallel gradient descent(SPGD) is a developing model-free optimum control algorithm in recent years,which is used for adaptive optics system for its advantages of inexpensive cost,beacon-free and so on.Laser propagation through atmosphere is simulated by the method of phase-screens,61-elements. deformable mirror is used as corrector,and the aberration caused by turbulence effects is corrected by SPGD algorithm.The numerical simulation results show that SPGD algorithm can be used in the adaptive optics system to correct the aberration caused by turbulence effects,the different perturbation amplitudes and gain coefficients are very important for the last corrected results,and the numerical simulation results on different propagation conditions are also shown.