Example of measuring Δν and A_max for the stars TIC 375621179 (HD 188512, top) and TIC 408842743 (HD 187691, bottom). Left panels: Stellar PSD (in gray). The background fit without the Gaussian envelope is overlaid (in red). The fitted Gaussian envelope above the background is marked with a dashed blue line. The vertical blue band corresponds to a 3σ Bayesian credible region around ν_max (vertical dashed orange line) as obtained from DIAMONDS. Middle panels: ACF² function to estimate Δν as computed on the original PSD (light gray curve) and on the PSD smoothed by Δν/10 (thick black curve). The dot-dashed blue line marks the position of Δν from the scaling relation. The selected Gaussian fit is shown as the orange curve, and its centroid is indicated by the vertical dashed orange line. The final estimate of Δν is represented by the green bullet, and its 1σ uncertainty is overlaid. Right panels: Smoothed amplitude spectrum (in gray). The estimate of A_max and its 1σ uncertainty are marked by the magenta bullet at the position of ν_max (vertical dotted blue line). The shaded blue region depicts the range over which the uncertainty on A_max is computed, ν_max ± σ_env.