High contrast adaptive optics system for meter class telescopes

This paper provides a status update on the Natural Guidestar (NGS) Adaptive Optics (AO) system being built for Castor, the meter class telescope at the Starfire Optical Range. We present a radiometric case study for a range of variable parameters such as source brightness, number of Shack-Hartmann sub-apertures, AO and Track loop frame rate and bandwidth. We gauge system performance by contrast and adapt the error budget to allow detection of a dim object near a bright star. We present wave band splits between the different AO components such as track sensor, wavefront sensor, scoring camera, and science camera. We show the different configurations that allow to switch between dim object and bright object tracking. The opto-mechanical design of the AO system is also presented.