Comparison of 1D CCFs for the Fe I signal between different datasets extracted from the peak of each K_pV_sys plot. Each panel represents the data from a different source: HARPS-N, FOCES Night 1, and FOCES nights 1, 2, and 3 combined, respectively. In each plot, the teal line represents the one-dimensional cross-correlation function, the black dashed line is the Gaussian fit to the peak in the plot, and the red dotted line is the model prediction, as discussed in Sect. 4.3. There is a small discrepancy in the model peak height for each result; this is likely driven by the larger wavelength range of FOCES, which changes the predicted cross-correlation result. The model-predicted CCF has values of slightly below zero near the peak of the function. This observation is attributed to cross-correlation aliases, a phenomenon explained in Borsato et al. (2023).