对于N单元变形镜,模型式无波前探测自适应光学系统只需N+1次远场光斑测量,收敛速度快。使用88单元变形镜、CCD成像器件等建立自适应光学系统仿真平台,分别从理论分析和仿真实验出发探讨模型式无波前探测自适应光学系统在噪声情况下的波前校正性能。结果表明:噪声条件下,基于模型的无波前探测自适应光学系统收敛速度保持不变;相同湍流条件时,不同噪声水平下的校正效果接近。与噪声水平50dB时的结果相比,按照给定湍流条件从弱到强,噪声水平为30dB时校正后平均RMS相对误差分别为4.75%、4.04%和2.58%。上述结果验证了基于模型的无波前探测自适应光学系统具有较强的抗噪能力。
For an N-element deformable mirror, the model-based wavefront sensorless adaptive optics (AO) system only needs N+I imaging acquisitions, which means rapid convergence. An AO system was simulated with an 88-element deformable mirror and a CCD. The convergence and the correction performance of AO system under noise were investigated. Results showed that the convergence under noise is the same as that of AO system under no noise. The correction effect is very close to each other under different noise for the same turbulence condition. Compared with correction results under 50 dB, averaged RMS relative errors of 30 dB are 4.75%, 4.04% and 2.58% respectively according to given turbulence conditions from weak to strong. Above results verified that the model-based wavefront sensorless AO system has a relative strong anti-noise capability.