激光发射系统通常受到瞄准误差的影响，使得发射光束的中心偏离靶目标，造成能量传输损失和系统性能下降。激光对目标照明后的散射回光信号可以反映瞄准误差的信息，通过对散射回光信号的测量可以对瞄准误差进行修正来提高激光发射系统的瞄准性能。研究了一种基于目标照明回光的瞄准误差修正方法。利用目标回光信息与瞄准误差的关系，通过随机并行梯度下降（SPGD）算法对瞄准误差进行校正，分析了影响瞄准误差校正精度的因素。实验数据验证了理论分析结果。

Laser beam pointing systems are generally affected by pointing errors. The pointing errors cause energy loss and the decline of the system performance while the center of the laser beam is not on the target. The pointing errors can be estimated from the scatter return photons back from the illuminated target. The performance of pointing error can be improved with close-loop control on the measurement of the return signals. In this paper a method to reduce pointing error based on the return signals from the illuminated target is studied. The stochastic parallel gradient descent (SPGD) algorithm is applied in this method. Some effects to influence the precision of pointing errors are analyzed. The analysis is verified by experiment.