大气湍流引起的动态波前畸变和望远镜的像差是限制望远镜分辨力的主要因素,如何准确地测量望远镜的像差是进一步提高望远镜分辨能力的关键问题。相位差法利用在焦面和离焦面上同时采集到的短曝光图像,恢复出瞬时波前相位分布,然后根据大气湍流的统计特性进行平均,可以实现对望远镜像差的估计。通过计算机模拟实验,对利用相位差法恢复光瞳上的波前相位和测量望远镜像差进行了研究。模拟研究结果表明,利用相位差法能有效地估计出望远镜像差,估计均方根误差约为0.08个波长。

Atmospheric turbulence and telescope aberrations all contribute to image degradation with ground-based telescopes. For measuring the telescope aberration with the disturbance of turbulence, a method based on phase diversity has been developed. Many instantaneous wavefront are independently reconstructed from pairs of simultaneously recorded focused and defocused short-exposure images using phase-diversity method. After that, by averaging these reconstructed wavefronts, the telescope aberrations are separated from dynamic wavefront induced by turbulence. The computer simulation of estimation of telescope aberration using phase-diversity method is conducted. The simulation shows phase-diversity method can estimate the telescope aberrations effectively and root-mean-square error is about 0.08 wavelengths.