Data sets used to study the impact of noise. Left panel: we show the data of the low S/N simulation with uncorrelated noise projected onto an unfolded torus. The scan on a single ring proceeds towards larger values of φ₂, the ring number increases along the horizontal axis (φ₁). Right panel: low S/N simulation, additionally containing 1 / f²-type noise. Strong correlations extending well beyond individual rings are visible.