The Simultaneous Operation of a Controllable Segmented Primary Mirror and Single Conjugate Adaptive Optics System part 1 -- Design Concept and Sensitivity Analysis

Abstract

The maintenance of primary mirror segment co-phasing is a critical aspect to the operation of segmented telescopes. However, speckle-based measurements of the phasing of the Keck primary have estimated semi-static surface aberrations of approximately 65 nm rms, which were not sensed by the current phasing control system. We propose directly sensing and controlling the primary via the adaptive optics (AO) system, as a Controllable Segmented Primary (CSP), to actively correct its phasing. We develop a methodology for separating the independent controllable signal of the CSP from the rest of the AO system and show estimations of the achievable measurement precision from models of the Keck-II AO system.