Implementation of an adaptive optics real-time control system based on a GPU for a 4-m class telescope

Abstract

Light propagating to a ground-based telescope passes through a region of varying refractive index, the turbulent atmosphere. And so even on top of the highest mountains, atmospheric turbulence limits the resolution of optical telescope, whatever their size, to approximately a 20cm telescope. Astronomers and engineers build ever larger telescope to collect more photons and study fainter and more distant object, but the only solutions to the atmospheric blurring is either to send telescope in space - an extremely expensive endeavor and offering limited flexibility -, or to develop dedicated systems correcting the atmospheric turbulence, so-called adaptive optics systems. Adaptive optics (AO) is a technique that flattens in real-time the distorted wavefront by measuring the residual errors and by controlling a deformable mirror. It improves the performance of ground-based telescopes up to the diffraction limit, which bring large im- provement in resolution and sensitivity. Over the last two decades, it has become a major technology in near-infrared astronomy and is favorable to many fields in astronomy : from the study of planetary systems, of stellar population, or the discovery of the supermassive black hole at the center of our galaxy. (Gilles Orban de Xivry, Implementation of an adaptive optics real-time control system based on a GPU for a 4-m class telescope, March 24 2017)