Three-panel figures for six epochs illustrating the quality of the local observing conditions. (I) Top panel, in a given figure: (normalised) median combined reference trend obtained from the selected set of reference stars for a given observation. Also listed is the chosen aperture size (in pixels) and the standard deviation of the trend curve. (II) Middle panel: background sky flux per pixel. (III) Bottom panel: airmass evolution and gives an easy overview of the number and frequency of discarded or lost frames.