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 loop slopes.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, problems such as the fratricide effect in multiple laser systems due to Rayleigh scattering, centroid gain variations, and limitations of the method are also addressed.

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The atmospheric optical turbulence profile, the strength of the turbulence as a function of altitude above the ground, can be used to determine the seeing statistics of a particular site. This information is useful for optimizing the tomographic process in Adaptive Optics systems and for characterizing the performance. In this paper, we describe a method to estimate the atmospheric turbulence profile based on the telemetry data coming out of GeMS, a Multi Conjugated Adaptive Optics (MCAO) instrument installed on the Gemini South telescope. The method is based on the SLODAR technique (SLOpe Detection and Ranging), where the wavefront slopes from two stars angularly separated on the sky are measured, and their cross-correlation is used to retrieve the atmospheric optical profile. We have modified the classical SLODAR method and adapted it for the closed loop, multiple laser guide stars case. In this paper we present our method, validation of it in simulation, and its application for on-sky data.

ERIS is an instrument that will both extend and enhance the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It will replace two instruments that are now being maintained beyond their operational lifetimes, combine their functionality on a single focus, provide a new wavefront sensing module that makes use of the facility Adaptive Optics System, and considerably improve their performance. The instrument will be competitive with respect to JWST in several regimes, and has outstanding potential for studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS had its final design review in 2017, and is expected to be on sky in 2020. This contribution describes the instrument concept, outlines its expected performance, and highlights where it will most excel.

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