An Efficient Lucky Imaging System for Astronomical Image Restoration

The resolution of astronomical imaging from large optical telescopes is usually limited by the blurring effects of refractive index fluctuations in the Earth’s atmosphere. In this paper, we develop a lucky imaging system to restore astronomical images through atmosphere turbulence on 1.23m telescope. Our system takes very short exposures, on the order of the atmospheric coherence time. The rapidly changing turbulence leads to a very variable point spread function (PSF), and the variability of the PSF leads to some frames having better quality than the rest. Only the best frames are selected, aligned and co-added to give a final image with much improved angular resolution. The system mainly consists of five parts: preprocessing, frame selection, image registration, image reconstruction, and image enhancement. The lucky imaging system has been successfully applied to restore the astronomical images taken by a 1.23m telescope. We have got clear images of moon, Jupiter, Saturn, and ISS, and our system can be demonstrated to greatly improve the imaging resolution through atmospheric turbulence.