By using the SCIDAR instrument at the VATT on the top of Mt. Graham and a very wide binary star with a separtion of 35", the vertical structure of the turbulence in the first few hundred meters above the telescope was measured. When using such a binary and analysing the cross-correlation images, a vertical resolution for the turbulence profile of a few tens of meters can be achieved near the ground. This permits to determine the inner structure and the wind sheer of the single turbulent layers inside the ground-layer. We present the principles and the data-reduction process of this method and show first results obtained with this method at Mt. Graham. As an application, we estimate the fraction of the turbulence between the dome of the VATT and the primary mirror of the LBT.
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