Stellar images taken by the Hubble Space Telescope at various focus positions have been
analyzed to estimate wave-front distortion. Rather than using a single algorithm, we found …

A new method has been developed for testing the optical quality of ground-based
telescopes. Aberrations are estimated from wideband long-exposure defocused stellar …

A set of observed noisy Hubble Space Telescope Faint Object Camera point-spread
functions is used to recover the combined Hubble and Faint Object Camera wave-front error …

An artificial-neural-network method, first developed for the measurement and control of
atmospheric phase distortion, using stellar images, was used to estimate the optical …

Context. Direct imaging of exoplanets requires very high contrast levels, which are obtained
using coronagraphs. But residual quasi-static aberrations create speckles in the focal plane …

Differential optical transfer function (dOTF) is an image-based, noniterative wavefront
sensing method that uses two star images with a single small change in the pupil. We …

Detailed knowledge of the image of the point spread function (PSF) is necessary to optimize
astronomical coronagraph masks and to understand potential sources of errors in …

Phase-retrieval measurements of point-spread functions from the pre-and post-repair
Hubble Space Telescope are presented. The primary goal was to determine the aberrations …

An important part of a large solar telescope is the ability to correct, in real time, optical
alignment errors caused by gravitational bending of the telescope structure and wavefront …

The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, modified Paul-
Baker design, with an 8.4-meter primary mirror, a 3.4-m secondary, and a 5.0-m tertiary …