Left: standard Deviation (STD) of the measured (solid lines) and simulated (dotted lines) relative SC (1628 spectral bins) absolute coherent flux |Γ_SC43|, the combined SC flux $\sqrt{F_{\mathrm{S}\mathrm{C}4}{F}_{\mathrm{S}\mathrm{C}3}}$, and the FT (6 spectral bins) absolute coherent flux |Γ_FT43| (different shades) for an examples exposure at high airmass on baseline 43. Right: same as the left panel, but for an exposure at low airmass.