First single star scidar measurements at Dome C, Antarctica

摘要

Aims. We investigate the first operational running of the Single Star Scidar (SSS instrument) under harsh weather conditions atDome C in Antarctica and examine continuous monitoring of the optical turbulence and wind speed profiles throughout the atmo-sphere.Methods. SSS is mainly composed of commercially available light-weight components and a 16 inch telescope installed on anequatorial mount. Scintillation patterns were computed (auto and cross-correlations) in real time and analyzed off line to retrievecontinuously vertical profiles of optical turbulence C_N~2 (h) and wind speed V(h), from the ground up to 20 km.Results. Using a simulated annealing method, we have analyzed about 6.5 h of observations, revealing the strong surface layer contri-bution to seeing degradation. SSS results show a good seeing agreement with simultaneous measurements with a Differential ImageMotion Monitor, even under very good seeing as low as 0.2 arcsec, as well as wind speed agreement when compared to the weatherarchive from NOAA.Conclusions. SSS has shown its usefulness for site characterization since it simultaneously measures CN2 and V profiles, from whichmost adaptative optic parameters are deduced, such as isoplanatic angle and coherence time of the wavefront. Due to its small size, itis well adapted for site characterization, even when low infrastructure is available.