High resolution astronomical image restoration system for large ground-based telescope

Abstract

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 letter, we develop a lucky imaging system to restore astronomical images through atmosphere turbulence on large 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. Our lucky imaging system is successfully applied to restore the astronomical images taken by a 1.23 m telescope. We get clear images of moon surface, Jupiter, and Saturn, and our system can be demonstrated to greatly improve the imaging resolution through atmospheric turbulence. OCIS codes: 100.3020, 010.1290, 010.7060. doi: 10.3788/COL201210.S21004. The resolution of all large ground-based telescopes is severely limited by the effects of atmospheric turbulence. At even the best sites, the resolution of large telescope is degraded by at least a factor of five in the visible. The recovery of the full theoretical resolution of large telescopes in the presence of atmospheric turbulence has been a major goal of technological developments in the field of as