Publication Info
Mikhail Vorontsov, Jim Riker, Gary Carhart, V. S. Rao Gudimetla, Leonid Beresnev, Thomas Weyrauch, Lewis C. Roberts, Jr., Deep turbulence effects compensation experiments with a cascaded adaptive optics system using a 3.63m telescope, Applied Optics, Volume 48, Issue 1, Pages A47-A57 (2009).
Abstract
Compensation of extended (deep) turbulence effects is one of the most challenging problems in adaptive optics (AO). In the AO approach described, the deep turbulence wave propagation regime was achieved by imaging stars at low elevation angles when image quality improvement with conventional AO was poor. These experiments were conducted at the U.S. Air Force Maui Optical and Supercomputing Site (AMOS) by using the 3.63m telescope located on Haleakala, Maui. To enhance compensation performance we used a cascaded AO system composed of a conventional AO system based on a Shack–Hartmann wavefront sensor and a deformable mirror with 941 actuators, and an AO system based on stochastic parallel gradient descent optimization with four deformable mirrors (75 control channels). This first-time field demonstration of a cascaded AO system achieved considerably improved performance of wavefront phase aberration compensation. Image quality was improved in a repeatable way in the presence of stressing atmospheric conditions obtained by using stars at elevation angles as low as 15°.
