title: Long-exposure filtering of turbulence-degraded wavefronts.
abstract: The quasi-static aberrations of optical telescopes are often determined using light from a star as the reference wavefront. We calculate the exposure time necessary to determine the amplitude of the phase aberrations for a given telescope to a given accuracy in the presence of atmospheric seeing. We implement a computational simulation of the atmosphere and present the root mean square of the generated wavefront Zernike amplitudes for a given exposure time. We find the exposure time τ required to reach a desired precision is strongly dependent on telescope diameter (τ∝D(8/3)) and can be many tens of minutes in extreme cases. We present the results so τ can be calculated for a range of telescopes and atmospheric parameters.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Cambridge, UK. j.gordon@mrao.cam.ac.uk
authors.forename: James A
authors.initials: JA
authors.lastname: Gordon
authors.forename: David F
authors.initials: DF
authors.lastname: Buscher
authors.forename: Fabien
authors.initials: F
authors.lastname: Baron