We describe the design and development status of GRAAL, the
Ground-layer adaptive optics assisted by Laser, which
will deliver enhanced images to the Hawk-I instrument on the VLT. GRAAL is an adaptive optics module, part of AOF,
the Adaptive optics facility, using four Laser- and one natural
guide-stars to measure the turbulence, and correcting for it
by deforming the adaptive secondary mirror of a Unit telescope in the Paranal observatory.
The outstanding feature of GRAAL is the extremely wide field of view correction, over 10 arcmin diameter, with an
image enhancement of about 20% in average in K band. When observing GRAAL will provide FWHM better than 0.3"
40% of the time. Besides the Adaptive optics facility deformable mirror and Laser guide stars, the system uses subelectron
L3-CCD and a real-time computing platform, SPARTA.
GRAAL completed early this year a final design phase shared internally and outsourced for its mechanical part by the
Spanish company NTE. It is now in manufacturing, with a first light in the laboratory planned in 2011.