Canary: The NGS/LGS MOAO demonstrator for EAGLE

Abstract

EAGLE is a multi-object 3D spectroscopy instrument currently under design for the 42-metre European Extremely Large Telescope (E-ELT). EAGLE will use open-loop Multi-Object Adaptive Optics (MOAO) to provide partial AO correction across a wide (5-10 arcmin) field of view. The novelty of this scheme is such that on-sky demonstration is required prior to final construction of an E-ELT instrument. The CANARY project will implement a single channel of an MOAO system on the 4.2m William Herschel Telescope. The CANARY project is undergoing a phased development plan that starts with demonstration of low-order open-loop AO correction using first NGS then Rayleigh LGS tomography, moving to a demonstration of high-order open-loop AO correction using LGS tomography. This final stage will also include 2 DMs in a woofer-tweeter configuration similar to that of EAGLE when installed at the E-ELT. We describe the requirements for the various phases of MOAO demonstration, the corresponding CANARY configurations and capabilities and the current designs of the various subsystems.