Squared visibilities V² (black) and rescaled differential squared visibilities (grey) at all three baselines for a small sample of successive frames (indicated by the frame index and the alternation of background colour) from dataset AT-MR-FT and at all wavelengths within each frame. Both quantities are superimposed for frames and baselines, where the visibility is close to , the estimated average squared visibility which is used to rescale ΔV². The ⟨s⟩ marker on the abscissa axis indicates a frame included in the “best 20%” selection.