Average values of squared visibilities and rescaled differential squared visibilities with their standard deviations per file for Baseline 1 of our datasets AT-MR-FT (top) and AT-LR-FR (bottom). Squared visibilities are plotted for frame selection levels of 100% and 20% (square and diamond symbols, respectively). Rescaled differential squared visibility (circle) are shifted for more clarity by vertical offsets of 0.1 and were obtained using almost 100% of the frames (see Sect. 4.1). In each case, the lines above and below the average values of squared visibility indicate the values of its standard deviation over one observation file, which are consistent with computed over the whole set of files, as shown in Fig. 6 and in Table 2. This figure is an illustration that shows that differential squared visibility has a very similar shape as the absolute ones but with a lower statistical dispersion.