Speaker
Description
MOSAIC is the only instrument proposed for the Extremely Large Telescope (ELT) that makes use of the full 10 arc minute field of view of the telescope.. The Ground Layer Adaptive Optics (GLAO) system for MOSAIC does not reach the diffraction limit but is designed to provide partial AO correction over this entire field, providing up to 1.5x the flux within a MOS aperture over that obtained with the telescope-delivered image quality. To achieve this, the GLAO system uses wavefront information from multiple laser and natural guide stars to identify only turbulence closest to the ground which is common to all lines of sight. Determining performance in this mode and understanding the interaction with the telescope control system is challenging, and places constraints both on system performance and the way in which astronomical observations can be made with MOSAIC. Here we describe some how the design and operation of the MOSAIC instrument addresses these challenges and how the AO system design has been optimised to enable wide-field multi-object spectroscopy.
