ИСТИНА

On the basis of 95500 MASS/DIMM measurements of optical turbulence profile obtained on Mt. Shatdzhatmaz in 2009-2011 we have constructed 2 atmosphere models for this summit: one consisting of 9 typical turbulence profiles, and other of 300 randomly selected profiles. Profiles represent Cn2 and wind speed values estimated at 13 standard MASS altitudes. We discuss advantages and disadvantages of these models from the point of view of AO simulation. We used these models as input parameters in analytical simulation (PAOLA tool) of AO system of future 2.5-m telescope of SAI. This simulation was used to estimate optimal parameters of this system and performance characteristics corresponding to these parameters. Second 300-profiles atmosphere model allowed to evaluate the performance in terms of statistical distributions of metrics. E.g. for subaperture size 0.35~m and optimizable exposure (lower limit 2~ms), the NGS AO system will deliver Strehl ratio more than 0.46 in R-band using R=13 guide star for 10\% of time.