Generalized SCIDAR Measurements at Mount Graham

We present the results of optical turbulence measurements conducted with a Generalized SCIDAR (scintillation detection and ranging) at Mount Graham during 16 nights in 2004 and 2005 at the Vatican Advanced Technology Telescope. The principle of the data reduction process is shown, as is the validation of the obtained results. From the measured and wind speed profiles, the astroclimatic parameters, such as seeing , isoplanatic 2 C e N 0 angle , wave-front coherence time , and isopistonic angle , are calculated, and their seasonal variation is ct c 00 P studied. With subtraction of the dome seeing, we obtained median values for (0.67), (2.7), (3.6 ms), ec t 00 0 and (3.3) that indicate that the astronomical seeing at Mount Graham is comparable to the best sites in the cP world. The seasonal variation of the vertical structure of the profiles is studied, and the contribution by the 2 CN ground-layer turbulence is analyzed. Furthermore, typical discretized profiles that are suitable for numerical 2 CN simulations are determined. Online material: color figures

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