Auto-correlation functions of one example StarSim RV data set for each of the four different spot distributions. Those are, from top to bottom, the ONE, POL, RAN, and TWO configurations. On the left-hand side the ACFs are shown for 0 < t <2000 days and on the right panel for 0 < t < 150 days to highlight the injected stellar rotation at P_rot = 25 d, and the spot lifetime of 100 d. Vertical red and blue dashed line mark P_rot and P_rot∕2 intervals, respectively.