GRAVITY's wavefront sensor and adaptive optics system
The wavefront sensor of GRAVITY will be of Shack-Hartmann-type using a lenslet mask with 9x9 micro-lenses. It will be sensitive in the spectral range between 1.4 and 2.4 microns.
The AO system of GRAVITY uses the existing MACAO deformable mirrors installed at the VLTI. The real-time computers will be based on the SPART-light platform designed by ESO.
Dedicated interferometric algorithms will be used to avoid unwanted disturbances. This includes deformable mirror saturation management, anti-windup, and piston control. Vibration tracking will be imlemented as well.