Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Cortés A., Neichel B., Guesalaga A., Osborn J., Rigaut F. and Guzmán D. (2012)

Atmospheric turbulence profiling using multiple laser star wavefront sensors. http://dx.doi.org/10.1111/j.1365-2966.2012.22076.x

Revista : Monthly Notices of the Royal Astronomical Society
Volumen : 427
Número : 3
Páginas : 2089–2099
Tipo de publicación : ISI Ir a publicación


This paper describes the data pre-processing and reduction methods together with SLOpe Detection And Ranging (SLODAR) analysis and wind profiling techniques for the Gemini South Multi-Conjugate Adaptive Optics System (GeMS).The wavefront gradient measurements of the five GeMS Shack–Hartmann sensors, each pointing to a laser guide star, are combined with the deformable mirror (DM) commands sent to three DMs optically conjugated at 0, 4.5 and 9 km in order to reconstruct pseudo-open loopslopes.These pseudo-open loop slopes are then used to reconstruct atmospheric turbulence profiles, based on the SLODAR and wind-profiling methods. We introduce the SLODAR method, and how it has been adapted to work in a closed-loop, multi-laser guide star system. We show that our method allows characterizing the turbulence of up to 16 layers for altitudes spanning from 0 to 19 km. The data pre-processing and reduction methods are described, and results obtained from observations made in 2011 are presented. The wind profiling analysis is shown to be a powerful technique not only for characterizing the turbulence intensity, wind direction and speed, but also as it can provide a verification tool for SLODAR results. Finally, problemssuch as the fratricide effect in multiple laser systems due to Rayleigh scattering, centroid gain variations, and limitations of the method are also addressed.