Squared coherence factors (μ²) and interferometric transfer function (TF) estimations (T²) for one representative observing night (June 9th) on the NE07-SE05 baseline. Filled symbols correspond to μ² data points for Vega (red diamonds) and the calibrator targets (blue squares). The interferometric TF is represented by the empty blue squares, which are derived from the calibrator measurements taking their known diameter into account. The solid line is an interpolation of the TF, obtained by fitting a second-degree polynomial to its estimated values. The 1-σ statistical and systematic error bars on the estimation of the TF are, respectively, represented by dotted and dashed lines. The two gaps during the night (one around 8:00 UT and the other around 9:30 UT) are due to the change in the long delay line offset and to some passing clouds.