Restoration of solar and star images with phase diversity-based blind deconvolution  

作　　者：李强 廖胜 魏宏刚 沈忙作 

机构地区：[1]State Key Laboratory of Optical Technologies for Microfabrication Institute of Optics and Electronics Chinese Academy of Sciences

出　　处：《Chinese Optics Letters》2007年第4期201-203,共3页中国光学快报（英文版）

基　　金：This work was supported by the National"863"Program of China under Grant No.8632774.

摘　　要：The images recorded by a ground-based telescope are often degraded by atmospheric turbulence and the aberration of the optical system. Phase diversity-based blind deconvolution is an effective post-processing method that can be used to overcome the turbulence-induced degradation. The method uses an ensemble of short-exposure images obtained simultaneously from multiple cameras to jointly estimate the object and the wavefront distribution on pupil. Based on signal estimation theory and optimization theory, we derive the cost function and solve the large-scale optimization problem using a limited memory BroydenFletcher-Goldfarb-Shanno （L-BFGS） method. We apply the method to the turbulence-degraded images generated with computer, the solar images acquired with the swedish vacuum solar telescope （SVST, 0.475 m） in La Palma and the star images collected with 1.2-m telescope in Yunnan Observatory. In order to avoid edge effect in the restoration of the solar images, a modified Hanning apodized window is adopted. The star image still can be restored when the defocus distance is measured inaccurately. The restored results demonstrate that the method is efficient for removing the effect of turbulence and reconstructing the point-like or extended objects.The images recorded by a ground-based telescope are often degraded by atmospheric turbulence and the aberration of the optical system. Phase diversity-based blind deconvolution is an effective post-processing method that can be used to overcome the turbulence-induced degradation. The method uses an ensemble of short-exposure images obtained simultaneously from multiple cameras to jointly estimate the object and the wavefront distribution on pupil. Based on signal estimation theory and optimization theory, we derive the cost function and solve the large-scale optimization problem using a limited memory BroydenFletcher-Goldfarb-Shanno （L-BFGS） method. We apply the method to the turbulence-degraded images generated with computer, the solar images acquired with the swedish vacuum solar telescope （SVST, 0.475 m） in La Palma and the star images collected with 1.2-m telescope in Yunnan Observatory. In order to avoid edge effect in the restoration of the solar images, a modified Hanning apodized window is adopted. The star image still can be restored when the defocus distance is measured inaccurately. The restored results demonstrate that the method is efficient for removing the effect of turbulence and reconstructing the point-like or extended objects.

关 键 词：ABERRATIONS Atmospheric turbulence Cost functions DECONVOLUTION Optical systems WAVEFRONTS 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]