Turbulent parameters at different heights in the atmosphere. Shack–Hartmann wavefront sensor data

Abstract

The paper presents the results of studies of wavefront distortions at different heights in the atmosphere. We have used measurement wavefront data to determine optical turbulence parameters along the line of sight of the Large Solar Vacuum Telescope. Through cross-correlation analysis of differential motions of sunspots at spaced wavefront sensor subapertures, we determined turbulent parameters at different heights at the Large Solar Vacuum Telescope site. The differential motions of sunspots characterize the small-scale structure of turbulent phase distortions in the atmosphere. Synchronous temporal changes in the amplitude of these distortions at certain regions of the telescope aperture are conditioned by turbulent layers at different heights. We have estimated the contribution of optical turbulence to integral distortions at the telescope aperture for layers 0–0.6, 0.6–1.1, 1.1–1.7 km. The contribution of optical turbulence concentrated in a 1.7 km atmospheric layer to the wavefront distortions at the aperture telescope is shown to be ~43 %.

Keywords

• telescope
• wavefront
• turbulence profiles
• adaptive optics