Correction of wavefront distortions in wide-field adaptive optics systems

In this paper, wide-field adaptive optics systems for ground-based solar telescopes are discussed. The features of constructing adaptive optics systems based on layer- and object-oriented approaches are considered. It is shown that the optimal adaptive optics system for the Large Solar Vacuum Telescope (LSVT) should be created on the basis of optical conjugation of deformable mirrors with turbulent layers of the atmosphere, the system for determining wavefront aberrations should be based on the use of a set of a narrow field of view sensors conjugated with telescope aperture, as well as a multi-directional wavefront sensor for turbulence tomography, designed on the basis of an object-oriented approach (measurements of wavefront aberrations in different directions). The schemes of pupil imagers that provide optical conjugation of the LSVT wavefront sensor with heights of 3 km as well as the upper atmospheric levels are considered. Direct optical conjugation of the Shack-Hartmann sensor with a turbulent layer is limited by a height of about 3 km (due to significant vignetting).