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Applied Optics

Applied Optics


  • Editor: James C. Wyant
  • Vol. 46, Iss. 17 — Jun. 10, 2007
  • pp: 3439–3443

Geometric method to measure astigmatism aberration at astronomical telescopes

Esteban Luna, Luis Salas, Leonel Gutiérrez, and J. Manuel Nuñez  »View Author Affiliations

Applied Optics, Vol. 46, Issue 17, pp. 3439-3443 (2007)

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A simple geometrical method to measure the aberration of astigmatism present in the wavefront that emerges from a telescope is presented. The method is based on the analysis of the external contour of the image of a slightly defocused star. An expression elliptical edge is obtained, which links the rms value of Z 22 to the geometric parameters of the ellipse. This expression is tested as a function of introduced defocus and astigmatism aberration in telescopes of the San Pedro Martir Observatory. It is shown that the method gives comparable results to wavefront tests, being capable of measuring astigmatism values of 60   nm and larger without the need for auxiliary optics.

© 2007 Optical Society of America

OCIS Codes
(080.1010) Geometric optics : Aberrations (global)
(110.6770) Imaging systems : Telescopes
(120.1680) Instrumentation, measurement, and metrology : Collimation

ToC Category:
Geometrical optics

Original Manuscript: November 10, 2006
Revised Manuscript: January 8, 2007
Manuscript Accepted: January 12, 2007
Published: May 18, 2007

Esteban Luna, Luis Salas, Leonel Gutiérrez, and J. Manuel Nuñez, "Geometric method to measure astigmatism aberration at astronomical telescopes," Appl. Opt. 46, 3439-3443 (2007)

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