ELP-OA: Final report of the feasibility study

R., Foy (1) , J. P. Pique (2) , V., Bellanger , P., Chevrou , A., Petit , C., Högemann , L., Noethe , M., Schöck , J., Girard , M., Tallon (1) , Éric Thiébaut (3) , J., Vaillant (4) , F.-C., Foy , M., van Dam (5)

1 CRAL - Centre de Recherche Astrophysique de Lyon
2 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]
3 INTERPSY - Laboratoire de psychologie de l'interaction et des relations intersubjectives
4 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux
5 W.M. Keck Observatory

We report the results of the feasibility study of the polychromatic laser guide star (PLGS) concept to measure the tilt without any natural guide star. Experiments on the sky at the LLNL (Ca) and at CEA/Pierrelatte (France) to measure the return flux in particular at 330nm reasonably fit the CEA Optical Bloch equation model of the population of the relevant enrgy levels of sodiu atoms in the mesosphere. The accuracy of the measurement of the differential tilt to derive the absolute tilt has been estimated from a horizontal propagation experiment. A phase retrieval algorithm has been developed to improve the measurement accuracy from the monochromatic components of the polychromatic image. A pendular seismometer has been developed to measure telescope vibrations. An end-to-end model has been developed to evaluate the performances expected from a PLGS at different telescopes. In conclusion, next steps of the "Etoile Laser Polychromatique pour Optique" programme. Adaptative" are described.

Domaines: Optique [physics.optics]

R., Foy, J. P. Pique, V., Bellanger, P., Chevrou, A., Petit, et al.. ELP-OA: Final report of the feasibility study. SF2A-2002: Semaine de l'Astrophysique Francaise, meeting held in Paris, France, June 24-29, 2002,, SFP, Jun 2002, Paris, France. pp.173. ⟨hal-01118347⟩