位相差异波前传感技术在大型空间光学相机中的应用

在位相差异技术原理的基础上,利用现有平台,通过室内实验以及室外推扫成像试验,检验了位相差异技术波前反演的效果.试验表明:以干涉仪实测波前与反演波前的残差均方根误差作为评价标准,基于位相差异技术的波前反演精度可达1/40λ(λ=632.8nm);同时,利用反演波前进行的图像复原滤波能够大幅改善推扫退化图像的品质,复原后图像信噪比的提升量优于40%,奈奎斯特频率处调制传递函数的提升量超过80%.间接地证明了位相差异波前反演技术的实际效能,为位相差异波前反演技术的空间应用奠定了基础.

Application of Phase Diversity Wave-front Sensing Technique to Large Space-borne Camera

Based on the fundamental principle of phase diversity technique, a prototype space-borne camera was used to experimentally demonstrate the effects of wavefront reversal of phase diversity technique through laboratory and outfield push-broom imaging experiments.Experimental results demonstrate that, the accuracy of wavefront reversal based on phase diversity technique is near 1/40λ(λ=632.8 nm)by using the root-mean-squares of residual wave-front errors between the really obtained wave-front through Zygo and the calculated wave-front through phase diversity as a criterion.At the same time, by carrying out deconvolution to the degraded push-broom images using the estimated wave-front, the image quality could be prominently improved.The signal-to-noise ratio could be improved at least 40% and the modulation transfer function at Nyquist frequency could be improved 80% above, which indirectly proves the effectiveness of phase diversity technique as well.The work reported in this manuscript will pave the way for in-orbit application of phase diversity based wave-front sensing technique in future.