
Proceedings Paper
Seeing trends from deployable Shack-Hartmann wavefront sensors, MMT Observatory, Arizona, USAFormat | Member Price | Non-Member Price |
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$17.00 | $21.00 |
Paper Abstract
Deployable Shack-Hartmann wavefront sensors (WFS) for the f/5 and f/9 secondary configurations have been used at
the 6.5-meter MMT Observatory (MMTO) since 2003. Probe mirrors for these WFS's are moved into the optical path of
the telescope between scientific observations multiple times each night. Results from the wavefront measurements are
then used to bend the primary mirror (M1) and to reposition the secondary mirror (M2) to correct for wavefront errors.
In addition to measuring the optical wavefront error, the Shack-Hartmann data are used to determine the delivered seeing
using the measured spot sizes. This study attempts to analyze the more than 75,000 WFS measurements and associated
seeing values obtained at the MMTO since 2003. The overall WFS data reduction and analysis procedure is discussed.
This data analysis includes: 1) finding the spots in each image, 2) centroiding the spots, 3) measuring a point-spread
function, 4) determining an average spot width and a derived seeing value, and 5) computing the best-fit Zernike
polynomial coefficients. Wavefront slopes are calculated from spot displacements and wavefront aberrations are fit with
a 19-term Zernike polynomial. As part of this study, the WFS-derived seeing values are correlated with other observing
parameters, such as mirror-air temperature contrasts. Finally, seasonal climate and local weather (e.g., prevailing wind
direction) effects on astronomical seeing are evaluated.
Paper Details
Date Published: 17 September 2012
PDF: 15 pages
Proc. SPIE 8444, Ground-based and Airborne Telescopes IV, 844432 (17 September 2012); doi: 10.1117/12.924897
Published in SPIE Proceedings Vol. 8444:
Ground-based and Airborne Telescopes IV
Larry M. Stepp; Roberto Gilmozzi; Helen J. Hall, Editor(s)
PDF: 15 pages
Proc. SPIE 8444, Ground-based and Airborne Telescopes IV, 844432 (17 September 2012); doi: 10.1117/12.924897
Show Author Affiliations
J. Duane Gibson, MMT Observatory, Univ. of Arizona (United States)
G. Grant Williams, MMT Observatory, Univ. of Arizona (United States)
G. Grant Williams, MMT Observatory, Univ. of Arizona (United States)
Thomas Trebisky, MMT Observatory, Univ. of Arizona (United States)
Published in SPIE Proceedings Vol. 8444:
Ground-based and Airborne Telescopes IV
Larry M. Stepp; Roberto Gilmozzi; Helen J. Hall, Editor(s)
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