Ground-layer Adaptive Optics for the 2.5 m Wide-field and High-resolution Solar Telescope

Abstract

The 2.5-m wide-field and high-resolution solar telescope (WeHoST) is currently under developing for solar observations. WeHoST aims to achieve high-resolution observations over a super-wide field of view (FOV) of 5 ′ × 5 ′ , and a desired resolution of 0.3 arcsec. To meet the scientific requirements of WeHoST, ground-layer adaptive optics (GLAO) with a specially designed wavefront sensing system is as the primary consideration. We introduce the GLAO configuration, particularly the wavefront sensing scheme. Utilizing analytic method, we simulate the performance of both classical AO and GLAO systems, optimize the wavefront sensing system, and evaluate GLAO performance in terms of PSF uniformity and correction improvement across whole FOV. The results indicate that, the classical AO will achieve diffraction-limited resolution; the suggested GLAO configuration will uniformly improve the seeing across the full 5 ′ × 5 ′ FOV, reducing the FWHM across the axis FOV to less than 0.3 ′′ (λ ≥ 705 nm, r 0 ≥ 11 cm), which is more than two times improvement. The specially designed wavefront sensor schedule offers new potential for WeHoST’s GLAO, particularly the multi-FOV GLAO and the flexibility to select the detected area. These capabilities will significantly enhance the scientific output of the telescope.