Real and simulated K_p − v plots for SYSREM iterations 3–10 cross-correlating with the H₂O template including clouds. In each plot, the dotted white line denotes the expected location of the peak, and the dashed yellow line denotes the actual location of the peak. First row: real data K_p − v map as shown in Fig. 10. Second row: simulated observation including all expected components (a ‘full’ simulation). Third row: simulated observation with an intentionally perturbed wavelength solution (‘bad λ’). Fourth row: simulated observation excluding telluric contamination (‘no T’). Fifth row: simulated observation excluding a planetary atmosphere (‘no P’).