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题名相位差法波前探测器设计
作者于学刚
学位类别硕士
答辩日期2008-06-12
授予单位中国科学院研究生院(云南天文台)
授予地点北京
导师刘忠
关键词相位差 波前探测 离焦量 双折射
其他题名The Design of Phase Diversity Wave-front Sensor
学位专业天体物理
中文摘要光波经过大气时,由于大气湍流的动态扰动,其光束质量将受到严重破坏,引起波前畸变。对于地基大型望远镜成像系统而言,大气湍流使得目标成像模糊、光能分散、分辨力严重下降。为了克服大气湍流对像质的破坏,过去的二十多年里,人们提出了许多旨在消除大气影响的高分辨成像方法。 相位差法波前探测[1]技术是一种后探测补偿方法,它是利用焦面像和离焦面像通过一个相位多样性算法来拟合相位或对目标复原。本文介绍了相位差法波前探测器原理、波前探测的图像模型和离焦量计算,离焦量与泽尼克系数的关系以及一些常见相位差法波前探测器。文中详细的分析了相位差法波前探测器的相关重要参数,如离焦量和离焦误差的分析、图像同步采集、光谱带宽、采样定理等。最后,我们利用晶体的偏振原理分像,设计了一款新型的相位差法波前探测器,并将焦面像和离焦像同时采集到同一个CCD(Charge Coupled Device)上。这种方法保证了两个图像的同步、实时,此外,光学系统简单。文中具体给出了一种新型波前相位差法探测器的设计方案、像差分析,并且模拟了波前相位差法探测器对模拟结果的影响。
英文摘要As light propagates through the atmosphere, light rays are distorted due to random variations in the index of refraction caused by atmospheric turbulence. This causes degradation of the images of astronomical object captured with a ground-based telescope. In order to overcome the atmospheric turbulence as the past 20 years, people made many designed to eliminate the atmosphere of high-resolution imaging method. Phase diversity 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 wave-front distribution on pupil. Phase Diversity (PD)[1] is to use focused and defocused images through a phase like diversity fitting algorithms to recovery phase or on the target. This requires two images, one is of the focused plane, and the other is from the defocused plane. In this paper the design's purpose is to image the two images into a CCD,At the same time ensuring the equal intensity of the two images with high signal to noise ratio. This paper presents a new sensor design and analyses its aberration,then simulate the solution of the PD wave-front sensor.
语种中文
学科主题天文学
页码54
内容类型学位论文
源URL[http://ir.ynao.ac.cn/handle/114a53/4883]  
专题云南天文台_抚仙湖太阳观测站
推荐引用方式
GB/T 7714
于学刚. 相位差法波前探测器设计[D]. 北京. 中国科学院研究生院(云南天文台). 2008.
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