| Issue |
2010
|
|
|---|---|---|
| Article Number | 05010 | |
| Number of page(s) | 6 | |
| Section | Wave front sensing | |
| DOI | https://doi.org/10.1051/ao4elt/201005010 | |
| Published online | 24 February 2010 | |
Shack-Hartmann tomographic wavefront reconstruction using LGS: analysis of spot elongation and fratricide effect
1
Office National d’Études et de Recherches Aérospatiales, BP 72, 92322 Châtillon,
France
2
LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot ; 5 Place Jules
Janssen, 92190 Meudon, France
a e-mail: clelia.robert@onera.fr
Noise effects induced by elongation have to be considered globally in a multi-channel tomographic reconstruction analysis. Such an analysis allows a fine estimation of performance and to compare launching options. We developed a modal LGS tomographic code based on pseudo-analytical matrix formalism. This modal analysis is computing and memory intensive. Therefore we limit the simulation to downscaled cases with diameters ranging from D = 4 to 21 m. We also limit the number of turbulent layers to a few equivalent layers. Including spot elongation and Rayleigh fratricide effect, when considering a global tomographic reconstruction, edge launching gives lightly better performance and limits the risk of possible underestimation of fratricide scatter.
© Owned by the authors, published by EDP Sciences, 2010