Top: example frame (exposure 1/18, integration 11/16) showing measured (left) and simulated (right) absolute SC coherent flux per wavelength bin for the six baselines (43, ..., 12) and their baseline averages ⟨SC⟩_b (different colors), taken at high airmass. Absolute coherent fluxes are normalized to the maximum flux in the exposure. Bottom: relative absolute coherent flux differences with respect to the time-averaged value for each baseline. Second order polynomial fits are indicated by dashed white lines. The systematic differences between the measured and simulated coherent fluxes are attributed to unknown fiber offsets, which are discussed in more detail in Sect. 4.1.2. The associated movie is available online.