Monitoring atmospheric turbulence profiles with high vertical resolution using PML/PBL instrument
Résumé
Wide-Field Adaptive Optics (WFAO) have been proposed for the next generation of telescopes. In order to be efficient, correction using WFAO require knowledge of atmospheric turbulence parameters. The structure constant of index-of-refraction fluctuations (C2 N ) being one of them. Indirect methods implemented in instruments as SCIDAR, MASS, SLODAR, CO-SLIDAR and MOSP have been proposed to measure C2 N (h) pro le through different layers of the atmosphere. A new monitor called the Profiler of Moon Limb (PML) is presented. In this instrument, C2 N (h) pro les are retrieved from the transverse covariance via minimization of a maximum likelihood criterion under positivity constraint using an iterative gradient method. An other approach using a regularization method (RM) is also studied. Instrument errors are mainly related to the detection of the Moon limb position and are mostly due to photon noise. Numerical simulations have been used to evaluate the error on the extracted pro le and its propagation from the detection to the inverse technique.