Top row: relative time-lag bias for the LS20.4 (continuous black curves) and LS40.8 (dashed red curves) light curves in experiment CD1. Bottom row: mean sample coherence for the LS20.4 (continuous black curves) and LS40.8 (dashed red curves) light curves in experiment CD1. Different columns correspond to different { (S/N)_x,(S/N)_y } combinations, while the estimates were determined from m = 20 segments in each case. The vertical dashed lines in all panels indicate ν_crit, while the blue dotted-dashed lines in the lower panels indicate the 1.2/(1 + 0.2m) mean sample coherence value (see Sects. 8 and 9 for details).