A new method has been developed for testing the optical quality of ground-based telescopes. Aberrations are estimated from wideband long-exposure defocused stellar images recorded with current astronomical CCD cameras. An iterative algorithm is used that simulates closed-loop wave-front compensation in adaptive optics. Compared with the conventional Hartmann test, the new method is easier to implement, has similar accuracy, and provides a higher spatial resolution on the reconstructed wave front. It has been applied to several astronomical telescopes and has been found to be a powerful diagnostic tool for improving image quality.
© 1993 Optical Society of America
Original Manuscript: November 19, 1992
Revised Manuscript: May 17, 1993
Manuscript Accepted: June 2, 1993
Published: November 1, 1993
Claude Roddier and François Roddier, "Wave-front reconstruction from defocused images and the testing of ground-based optical telescopes," J. Opt. Soc. Am. A 10, 2277-2287 (1993)