Vertical Profiles of Optical Turbulence and Estimates of Turbulence Outer Scale above the Baykal Astrophysical Observatory

Abstract

The study of spatiotemporal structure of optical turbulence and the development of techniques for determining its characteristics at different altitudes in the atmosphere are of great importance for astronomical adaptive optics. Design of an adaptive optics system and technical characteristics of its components largely depend on optical turbulence along the line of sight of a telescope. In this paper, the technique for estimating the vertical profiles of air refractive index structure characteristic is modified. Based on ERA5 reanalysis data, this method was used to derive statistically representative vertical profiles of air refractive index structure characteristic and turbulence outer scale at the Large Solar Vacuum Telescope (LSVT) site. The problem of estimating the turbulence outer scale is discussed taking into account surface mast micrometeorological measurements and optical measurements at the LSVT. The results are the basis for constructing a multi-mirror adaptive optics system for the LSVT. In particular, the above profiles are important for further refinement of the optical conjugation heights. The suggested technique can also be used to describe optical turbulence over other ground-based solar telescopes.