Free access
Astron. Astrophys. Suppl. Ser.
Volume 144, Number 3, June II 2000
Page(s) 533 - 540
DOI: 10.1051/aas:2000228

Astron. Astrophys. Suppl. Ser. 144, 533-540

Atmospheric sodium monitor for Laser Guide Star Adaptive Optics

N. Ageorges1 - N. Hubin2

Send offprint request: N. Ageorges,

1 - National University of Ireland, Galway, Physics Department, Galway, Ireland
2 - European Southern Observatory, Karl Schwarzschildstraße 2, D-85748 Garching, Germany

Received May 17, 1999; accepted April 3, 2000


Laser Guide Star Adaptive Optics (AO) makes use of a laser to excite the mesospheric sodium (Na) layer and thereby creates an artificial star that can be used as reference for the AO wavefront sensor. The intensity of the created star depends strongly on the amount of Na present in the atmosphere. Experiments to measure the column density and details of the excitation and scattering properties of sodium atoms in the corresponding atmospheric layer are thus very important to refine the design parameters of laser and assess the power requirement.

This article reviews the current knowledge on the mesospheric sodium derived from both astronomical and atmospherical studies. It then presents possible methods to study the sodium layer characteristics relevant for adaptive optics laser guide star systems.

Key words: instrumentation: adaptive optics -- instrumentations: miscellaneous -- methods: observational

SIMBAD Objects

Copyright The European Southern Observatory (ESO)

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see You should disable this module if you wish to use the OpenURL server that you or your library have defined.