Simultaneous Measurements of the Fried Parameter r₀ and the Isoplanatic Angle theta₀ using SCIDAR and Adaptive Optics - First Results

We present first results of a simultaneous atmospheric turbulence measurement campaign at the Calar Alto (Spain) 1.23m and 3.5m telescopes. A SCIDAR instrument and the Calar Alto Adaptive Optics system ALFA were used at the 1.23m and 3.5m telescopes respectively to determine essential turbulence parameters like the Fried parameter r_0, the isoplanatic angle theta_0, and, in the case of SCIDAR, the C_n^2 profile of the atmosphere. Both closed-loop and open-loop data were obtained with ALFA. The desired parameters were then calculated from this. This paper shows a comparison of the results obtained from the two different systems for several times during a period of three nights.