Frequency parameters of wavefront variations from optical measurement data

Abstract

For adaptive optics systems, one of the fundamental task to be decided is determination of the frequency characteristics of wavefront distortion variations in the focus of a ground-based solar telescope. It is a classical approach to use the atmospheric coherence time related to the vertical distribution of turbulence and wind speed. Besides, small-scale variations of wavefront induced due to turbulence for understanding the large-scale structure of atmospheric turbulence it is important to estimate frequencies of large-scale (low-frequency) turbulent components. The paper presents the results of the analysis of the frequency characteristics of wavefront distortion variations recorded in the adaptive optics system of the Large Solar Vacuum Telescope of the Baikal Astrophysical Observatory.

Method for determining the wavefront distortions from the Shack-Hartmann sensor measurements

“…The algorithms discussed can be used in problems of determining the altitude profile of turbulent fluctuations of the air refractive index in systems of automatic registration. Also, obtained results in this study are important for developing system of adaptive optics of Large Solar Vacuum Telescope [11][12][13][14] and development of remote sensing methods for optical turbulence profiling.…”