<title>Initial performance of the Keck AO wavefront controller system</title>

Abstract

The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control ioop to remove tilt from the incoming wavefront, and a deformable mirror conirol loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

Characterization of adaptive optics at Keck Observatory: part II

“…The wave-front controller is described in detail in Johansson et al 21 and the features of the controller required in the model are simply stated here. A schematic of the TT and DM feedback loops for the Keck AO system is displayed in Figure 5.…”

<title>Neptune and Titan observed with Keck Telescope adaptive optics</title>

“…The real-time computer is based on the Mercury RACE architecture, and uses sixteen Intel i860 floating-point CPUs. Overall system bandwidth is typically about 30 Hz using bright natural guide stars 2 as a wavefront reference.…”