DRAGON, a flexible, visible-light AO testbed
Stephen Rolt, Alastair Basden, Nazim Bharmal, Nigel Dipper, Deli Geng, Tim Morris, Richard Myers
DRAGON is a Durham University adaptive optics testbed, designed to accurately simulate the effects of the atmosphere for the purposes of developing high-order adaptive optics, targeted towards visible AO correction. The design consists of altitude-adjustable phase screens, a realistic sodium guide-star emulator and a set of fixed targets that can also be used as natural guide stars. The design has been optimised for both wide-field (2.5’ FoV, hence MCAO/MOAO) and on-axis (SCAO) situations with 4-8m class telescopes. Since it is targeted toward visible AO, high order wavefront sensing and correction are obvious steps towards ELT-scale AO development and a key aspect of DRAGON is the integration of the Durham RTC system (see Basden, these proceedings). The design of DRAGON is discussed and its extensions towards simulating ELT-scale AO in its current configuration is explained, together with a future design explicitly scaled for ELT-scale pupils.