Observed calibrated visibilities (V²) on δ Sco versus the spatial frequency (m/μm). Each panel is for a baseline. The red curves are the result of the global fit by a disk+point model. The (u,v) plane coverage (m/μm) of the observations is displayed in the bottom-right panel. North is up and east to the right. The radial tracks come from the spectral dispersion over 3 spectral channels.