Autocorrelation function plots of selected triangles and quadrangles. Representative models are shown. Black, red, and blue lines indicate ACFs for noiseless data, 16 Gbit s ⁻¹, and 4 Gbit s ⁻¹, respectively. Panels marked with a red star show ACF _ϕ on a different ordinate scale, as indicated to the left in that row; other panels in the same row are on the scale show in the upper left panel. The dotted line shows the period of the hot spot orbit.