19 September 2017 Onur Keskin


Speaker             : Onur Keskin, Işık University
Title                     : Adaptive optics and derotator development of the DAG 4m telescope at Center of Optomechatronics Research and Application (OPAM)
Date                     : September 19, 2017 Tuesday
Time                    : 2:30 P.M.
Cookie & Tea  : SCI 103 2:15 P.M.
Place                   : SCI 103

Turkish astronomers have initiated a project to build a 4 m telescope in Eastern Anatolia, near the City of Erzurum, on the Karakaya Tepeleri, at 3170 m altitude. The name of the observatory is DAG, for Dogu Anadolu Gozlemevi. The objective is to give national astronomers an easy way to conduct observations (large international telescopes are difficult to access), and build national expertise in astronomical instrumentation research and development. DAG will be a versatile telescope, dedicated to observations in the near infrared (NIR), and visible (VIS), over large fields in seeing limited mode, or medium to small field in adaptive optics (AO) mode.
Along with the optical design and project management of the DAG project, OPAM is the Research Center who’s in charge of both the design and bulding of AO system and DAG’s derotators. In this presentation, followed by the basic AO concept and derotator systems, the preliminary design result of an analysis of our long term plan: a versatile system allowing Extreme Adaptive Optics (ExAO) as well as Ground Layer Adaptive Optics (GLAO) using the very same wavefront sensor (WFS) and deformable mirror (DM) hardware will be discussed, along with the derotator that will be placed inside of the telescope’s flange to compensate for the Erath’s rotation. Indeed, thanks to the possible adjustment of the PWFS sensitivity and spatial sampling, in one hand, and the large number of available actuators on the other, which can be grouped together to make super-actuators, it should be possible to fully modulate the level of correction to the seeing conditions and the natural guide star constellation and brightness available around the object of interest. This, plus the fact that we have the freedom to choose the best control scheme (tomography or not, considering all the NGS or not) allows us to make the maximum possible out of a single DM system.

Isik University