title: Adaptive optics: wave-front correction by use of adaptive filtering and control.
abstract: A class of adaptive-optics problems is described in which phase distortions caused by atmospheric turbulence are corrected by adaptive wave-front reconstruction with a deformable mirror, i.e., the control loop that drives the mirror adapts in real time to time-varying atmospheric conditions, as opposed to the linear time-invariant control loops used in conventional adaptive optics. The basic problem is posed as an adaptive disturbance-rejection problem with many channels. The solution given is an adaptive feedforward control loop built around a multichannel adaptive lattice filter. Simulation results are presented for a 1-m telescope with both one-layer and two-layer atmospheric turbulence profiles. These results demonstrate the significant improvement in imaging resolution produced by the adaptive control loop compared with a classical linear time-invariant control loop.
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095-1597, USA. gibson@seas.ucla.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Gibson
authors.forename: C C
authors.initials: CC
authors.lastname: Chang
authors.forename: B L
authors.initials: BL
authors.lastname: Ellerbroek