Astron. Astrophys. 338, L100-L102 (1998)

Letter to the Editor

Fixing the LGS tilt problem using tomography

Roberto Ragazzoni ¹ and François Rigaut <sup>2

1</sup> Astronomical Observatory of Padova, vicolo dell'Osservatorio 5, I-35122 Padova, Italy
² Southern European Observatory, Karl-Schwarzschild-Strasse 2, D-85386 Garching bei München, Germany

Received 15 June 1998 / Accepted 1 September 1998

Abstract

We propose a simple scheme to solve the tilt indetermination problem in adaptive optics compensation with laser guide stars. This technique, providing tomographic turbulence analysis works, increases the area into which a tip-tilt guide star has to be found by approximately two orders of magnitude, boosting the sky coverage close to 100% at visible wavelengths. In addition, the proposed scheme provides a tilt measurement free of anisoplanatism error. It has numerous engineering advantages compared to other tilt retrieval techniques, as it does not require special auxiliary equipment nor an increased laser power.

Key words: adaptive optics atmospheric effects telescopes

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Tomographic tilt recovery
  • 2.1. Geometry of the problem
  • 2.2. Improvement with an additional LGS
  • 2.3. Extension cases
• 3. Discussion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: September 17, 1998
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