Left: fraction of real SDCs as estimated through visual inspection (red symbols and solid line). Right: fraction of visually confirmed real SDCs that have been identified as real SDCs by our automated detection scheme (f_real – blue round symbols), and fraction of visually confirmed spurious SDCs that have been misclassified as real SDCs by our automated detection scheme (f_spur – purple square symbols). These two curves can directly be compared to our detection simulation results presented in Fig. 8. All error bars correspond to Poisson noise.