Signal to noise for various cases. Solid is cross-correlation is m = 0 for i = 0° and dashed the corresponding fits. The dotted line in-dicates the cross-correlation for m = l, 4 km s⁻¹ equatorial rotation and i = 90° while the dash-dotted line indicates the corresponding fit. In all cases the absolute value of the signal-to-noise ratio is shown divided by the corresponding l = 0 cross-correlation value.