Analysis and comparison of the atmospheric parameters retrieved from a Ex-AO instrument with the astroclimatic monitoring system
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Paranal Observatory has a set of astroclimate monitoring instruments; such as DIMM, MASS-DIMM and SLODAR which are delivering information about the sky quality in terms of; seeing, coherence time, high altitude wind speed (200mb) and Cn2 profiles to support the observations. SPHERE instrument is an Extreme Adaptive Optics that uses a Shack-Hartmann wavefront sensor running at close loop frequency of 1.3KHz. The instrument saves close loop snapshot every minute and from the data saved the system retrieves the r0 and the cross wind speed. The wind speed is calculated using a cross-corrrelation based on the peak identification. The knowledge of t his parameter is essential to understand the performances of the AO system, and to optimize its control laws every minutes. The data from the astroclimatic system monitor will help to correlate the turbulence events with the transverse wind speed retrieved from SPHERE close loop data. The goal of this work is also to compare the different atmospheric monitors with the effective turbulence estimation from the focal plane itself (Differential Tip-Tilt Sensor).
[1] Kjetil Dohlen,et al. SAXO, the eXtreme AO system of SPHERE (I) System overview and global laboratory performance , 2015 .
[2] Andrei Tokovinin,et al. Combined MASS-DIMM instruments for atmospheric turbulence studies , 2007, 0709.2081.
[3] Jean-Louis Lizon,et al. The differential tip-tilt sensor of SPHERE , 2010, Astronomical Telescopes + Instrumentation.
[4] S. Chueca,et al. Statistics and analysis of high-altitude wind above the Canary Islands observatories , 2004 .