Adaptive optics (AO) is a technique that corrects in real time for image distortions caused by motions in the Earth’s atmosphere. The Big Bear Solar Observatory (BBSO) New Solar Telescope (NST) depends on a state-of-the-art AO system to enable diffraction-limited imaging (0.08 arc seconds in the visible). The current NST AO incorporates a Shack-Hartmann lens let array with 308 sub apertures for measuring wavefront error. The wavefront distortion is the corrected using a deformable mirror (DM) with 357 piezoelectric actuators.
AO systems, such as AO-308, can deliver diffraction-limited images over a relatively small angle on the sky known as isoplanatic patch. Image quality gradually deteriorates with increasing angle from the patch. The size of the patch varies with seeing conditions.
