Simultaneous operation of a controllable segmented primary mirror and single conjugate adaptive optics system, part 2: simulated operation

There are scientific and technological needs to improve the co-phasing of the primary mirrors of segmented telescopes. We have developed a methodology for using the wavefront sensor of an adaptive optics (AO) system to disentangle the phase of a controllable segmented primary mirror (CSP) from the residual phase aberrations to be corrected by the rest of the AO system. We show simulations of the Keck-II AO system where we simultaneously control the CSP surface and a single-conjugate AO system using a pyramid wavefront sensor in a low-bandwidth closed loop, resulting in significantly decreased aberrations on the primary and improvements in the performance of the AO system. Analysis of on-sky telemetry data from the Keck-II AO system validates these simulations and shows that accurate measurements of the primary phase can be made in the presence of real atmospheric turbulence. Ultimately, we suggest that it is feasible to simultaneously monitor and control the CSP with an AO wavefront sensor while in closed-loop operation and that doing so may significantly improve the performance of the AO system.