Esposito, S. and Ragazzoni, R. and Riccardi, A. and O'Sullivan, Créidhe and Ageorges, N. and Redfern, M. and Davies, R.
(2000)
Absolute Tilt from a Laser Guide Star:
A First Experiment.
Experimental Astronomy, 10 (1).
pp. 135-145.
ISSN 0922-6435
Abstract
Absolute tip–tilt recovery using a tilt signal measured on a Laser Guide Star is a central
problem in the framework of the development of Adaptive Optics Systems reaching full sky coverage
down to visible wavelengths. In the past few years, various techniques aimed at solving this problem
have been proposed. However only a couple of these has been recently tested in practice. We report
about an experiment aimed at evaluating the performance of one of these techniques called the
‘Elongation Perspective’ technique. Our experiment has been performed using the ALFA system in
Calar-Alto (Spain) and involves the simultaneous operation of the 3.6 m and the 2.2 m telescopes at
the Observatory. This article describes the telescope configuration used, as well as the data reduction
process carried out in order to estimate the scientific object tilt. The technique performances are
discussed in terms of the residual tilt error variance and related correlation coefficient. The analysis
shows that, despite the low SNR of our measurements, the atmospheric tilt variance is reduced to 80%
of its initial value corresponding to a correlation coefficient of about 0.6. To get a better estimate of
the performance achievable using this technique, the tilt error variance due to photon noise in the laser
measurement is estimated and removed from the obtained tilt error variance. When this correction is
done, this variance is reduced to about 50% of its initial value, showing that the use of this technique
can give rise to a significant reduction of the scientific object image motion.
Item Type: |
Article
|
Additional Information: |
The definitive version of this article is available at DOI: 10.1023/A:1008115109976 |
Keywords: |
adaptive optics; laser guide star; |
Academic Unit: |
Faculty of Science and Engineering > Experimental Physics |
Item ID: |
7100 |
Identification Number: |
https://doi.org/10.1023/A:1008115109976 |
Depositing User: |
Dr. Créidhe O'Sullivan
|
Date Deposited: |
05 May 2016 14:53 |
Journal or Publication Title: |
Experimental Astronomy |
Publisher: |
Kluwer Academic Publishers |
Refereed: |
Yes |
URI: |
|
Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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