天文图像多帧盲反卷积收敛性的增强方法

天文图像多帧盲反卷积的收敛性受到初始目标、约束条件和光子噪声等因素的影响.提出了用实际光学成像系统参数确定频率带宽有限约束的方法.用Knox-Thompson 方法重构初始目标相位形成盲反卷积算法的初始目标函数.研究了一种新颖的有效减小光子噪声、边缘效应和振铃现象的方法.根据最大似然估计理论，用期望最大化的优化方法建立了改进的严格约束多帧盲反卷积算法.模拟图像和实际天文图像的复原结果表明，所建立的多帧盲反卷积，可以有效克服大气湍流和减小光子噪声，改善天文观察图像的分辨率，并部分消除光学系统衍射效应对恢复图像的影响. 关键词： 大气光学 天文观测 图像处理和恢复

Approaches to convergence enhancement of multiframe blind deconvolution of astronomical images

The convergence property of multiframe blind deconvolution applied to improve the resolution of astronomical images is influenced by initial object estimate, constraint conditions and photon noise. A method of determining band limitation of the point-spread function from the optical imaging system parameters is proposed. The initial object estimate of blind deconvolution algorithm is formed by using Knox-Thompson method to reconstruct object phase from short-exposure images. A novel method, which is used to decrease photon noise, edge effects and ringing of restoration images is developed. An improved muhiframe blind deconvolution algorithm with a strict constrained optimization method of the expectation-maximization based on maximumlikelihood estimation is presented. The restored images of the simulation data, and real Mars and solar-granulation data show that the proposed multiframe blind deconvolution algorithm is valid for overcoming effects of atmospheric turbulence and photon noise and improving the resolution of real observed astronomical images, and capabel of partly removing the diffraction effect of optical system on restored images.