Cross-correlation results (normalised to units of S/N) for different ways of combining the individual data sets. In each case, the black dashed line represents the result when combining all the data together. Top left: orange lines are the CCFs from each individual observation taken in the L3262 setting. The red line is the combination of all L3262 observations. No dramatic improvement in S/N is acquired from this combination. Top right: same, but for the case of L3340. Middle left: same, for the case of L3426. Middle right: same, for the case of M4318. Bottom: here, a set of single observations from each spectral setting is plotted as orange lines. Their combination is plotted as a red line. In this case, a significant improvement is gained from combining the data sets, almost reaching the S/N level from the full data set.