Wavefront sensors for adaptive optical systems

Possibilities of constructing a wavefront sensor for the adaptive system in the Big Solar Vacuum Telescope are considered. A modified correlation tracker (MCT) is proposed. The sensor is tested by measuring the displacement of the image of the solar granulation pattern in the first and second foci of the telescope under clear vision conditions. The change in the quality of the image being transferred to the second focus and the measured displacement of the image of solar granulation in the second focus with extremely good vision conditions and a certain granulation structure are analyzed. The effect of reduction of the input aperture to 170 mmon the image quality and, hence, on MCT operation is analyzed.