空间相机次镜在轨校正仿真分析

Simulation Analysis of On-orbit Alignment for The Space Camera Secondary Mirror

针对空间环境变化引起的面形误差和位置误差导致空间相机成像品质下降的情况,提出一种次镜调整补偿系统像差的多软件联合仿真方法。采用次镜调整来补偿系统像差的方法,利用条纹泽尼克多项式来拟合系统波前像差,建立像差系数和次镜调整量之间的多视场灵敏度矩阵模型,进而通过最小二乘法迭代计算求解出各调整量,实现次镜在轨校正的闭环控制。以偏视场同轴三反消像散光学系统为例进行仿真分析,次镜多次迭代调整可以使系统多个视场的波像差接近原始设计值。仿真结果验证了次镜在轨调整的像差补偿作用,为空间相机在轨主动像差校正技术提供了工程应用参考价值。

In order to compensate the optical additional wavefront（WF） error caused by space environment induced position and figure changes of the mirror, a multi-software co-simulation method is proposed in the paper by actively controlling the six Degrees of Freedom（DOF） of the Secondary Mirror（SM）.The WF aberrations are compensated by adjusting the SM and are simulated by Fringe Zernike polynomials. Then the sensitivity matrix model based on multi fields is established between the aberration coefficients and the alignment state of secondary mirror. Finally, the adjustment magnitude for the SM is calculated by the least square method, thus realizing the closed loop control of the SM adjustments on orbit. Taking a coaxial three-mirror anastigmatic system as an example, the Root-Mean-Square（RMS） of WF error at multi-fields could be close to the original designed performance after many adjustment iterations. The simulation results show that this method is very effective in compensating the WF aberrations, providing some valuable references for on-orbit alignment of the space camera in future practical engineering applications.