First results on a Cn2 profiler for GeMS
Abstract
GeMS (the Gemini MCAO System) is a facility instrument for the Gemini-South telescope, currently in its final commissioning phases. The system includes 5 laser guide stars, 3 natural guidestars, 3 deformable mirrors optically conjugated at 0, 4.5 and 9km and 1 tip-tilt mirror. Among these unique features, a Cn2 Slodar Profiler is being implemented. The Cn2 profile is reconstructed from the slopes seen by the 5 high order WFS, each one pointing in a LGS direction. Residuals from the 16x16 subapertures WFSs and DM commands are used to obtain pseudo-open loop data for SLODAR, allowing us to reconstruct up 16 layers. The first part of this paper describes the algorithms used for this purpose and the results obtained from simulations and from artificially generated turbulence, resulting from exiting the 3 DMs. These latter have been extensively used to calibrate the method in a controlled environment. The second part of the paper presents the first on-sky results obtained during commissioning nights. In particular, we compare these results with external data obtained from a MASS/DIMM instrument.
- Publication:
-
Second International Conference on Adaptive Optics for Extremely Large Telescopes. Online at <A href="http://ao4elt2.lesia.obspm.fr">http://ao4elt2.lesia.obspm.fr</A
- Pub Date:
- September 2011
- Bibcode:
- 2011aoel.confE..77C