Adaptive Optics for Extremely Large Telescopes 4 – Conference Proceedings

Contemporary AO systems, such as the Multi-Object Adaptive Optics system (MOAO) RAVEN currently associated with the Subaru Telescope, can suer from signicant Non-Common Path Aberrations (NCPA). These errors ultimately aect image quality and arise from optical path dierences between the wavefront sensor (WFS) path and the science path. A typical correction of NCPA involves estimating the aberration phase and correcting the system with an oset on the deformable mirror (DM). We summarize two methods used to correct for NCPA on an experimental bench. We also successfully calibrate the NCPA on RAVEN using one of these methods. Finally, we report on some rst science results with RAVEN, obtained after NCPA correction.