Title

Diffraction Effects Of Telescope Secondary Mirror Spiders On Various Image-Quality Criteria

Authors

Authors

J. E. Harvey;C. Ftaclas

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Appl. Optics

Keywords

SPIDER DIFFRACTION; TELESCOPE DIFFRACTION EFFECTS; IMAGE-QUALITY; CRITERIA; ENCIRCLED ENERGY; Optics

Abstract

Diffraction from secondary mirror spiders can significantly affect the image quality of optical telescopes; however, these effects vary drastically with the chosen image-quality criterion. Rigorous analytical calculations of these diffraction effects are often unwieldy, and virtually all commercially available optical design and analysis codes that have a diffraction-analysis capability are based on numerical Fourier-transform algorithms that frequently lack an adequate sampling density to model narrow spiders. The effects of spider diffraction on the Strehl ratio (or peak intensity of the diffraction image), full width at half-maximum of the point-spread function, the fractional encircled energy, and the modulation transfer function are discussed in detail. A simple empirical equation is developed that permits accurate engineering calculations of fractional encircled energy for an arbitrary obscuration ratio and spider configuration. Performance predictions are presented parametrically in an attempt to provide insight into this sometimes subtle phenomenon.

Journal Title

Applied Optics

Volume

34

Issue/Number

28

Publication Date

1-1-1995

Document Type

Article

Language

English

First Page

6337

Last Page

6349

WOS Identifier

WOS:A1995RW22700003

ISSN

0003-6935

Share

COinS