Sky coverages on ELTs with a reference area much larger than the compensated one
Viotto, V. (a,b), Ragazzoni, R. (a), Arcidiacono, C. (c), Dima, M. (a), Magrin, M. (a), Farinato, J. (a)
a - INAF, Astronomical Observatory of Padova b - University of Padova - Astronomy Department c - INAF, Astronomical Observatory of Arcetri
Sky coverage for MCAO systems has been the subject of a large number of studies in the past decade or so. The resulting figures, further to have the chance of being refined by actual measurements carried out at the largest 8m class telescopes, have to be updated and validated for the most recent approaches in ELT adaptive optics corrections. In particular, techniques employing the use of several virtual deformable mirrors can take advantage of a field of view, inside which references can be found, that is much larger than the area where the correction is actually made. While a parallel with similar studies for Multi Objects AO can be traced down, we revise here the various proposed approaches and we show the results of similar computations using the novel concepts and gauging the outcome with the more recent on-sky available data. The comparison with similar computations that can be made for artificially generated beacon is briefly discussed.