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Proceedings Paper

One-shot focusing using the entropy as a merit function
Author(s): V. Suc; S. Royo; A. Jordán; G. Bakos; K. Penev
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Paper Abstract

We present a method for measuring focus aberrations on wide field telescopes based on an entropy analysis of a single image. First, we calibrate the system using the evolution of the entropy as a function of the position in the field and the focuser position. This gives us a model defining the tilt of the sensor and the field curvature. Then, using a single image at a given position of the focuser in which the mean defocus is unknown, we can compute the position where the focuser must be set in order to minimize the focus aberration over the whole field.

Paper Details

Date Published: 25 September 2012
PDF: 10 pages
Proc. SPIE 8449, Modeling, Systems Engineering, and Project Management for Astronomy V, 844914 (25 September 2012); doi: 10.1117/12.927021
Show Author Affiliations
V. Suc, Pontifícia Univ. Católica de Chile (Chile)
Univ. Politécnica de Catalunya (Spain)
S. Royo, Univ. Politécnica de Catalunya (Spain)
A. Jordán, Pontificia Univ. Católica de Chile (Chile)
G. Bakos, Princeton Univ. (United States)
K. Penev, Princeton Univ. (United States)

Published in SPIE Proceedings Vol. 8449:
Modeling, Systems Engineering, and Project Management for Astronomy V
George Z. Angeli; Philippe Dierickx, Editor(s)

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