Histogram of various UD properties for both time sequences. Mean intensity— I _mean, maximum intensity— I _max, maximum-to-background intensity ratio— I _max/ I _bg, effective diameter— D _eff, horizontal speed— V, lifetime— T, birth–death distance— L _bd, and trajectory length— L _tj. Bin sizes are 0.05 I _QS, 0.05 I _QS, 0.15, 40 km, 100 m s ⁻¹, 2 minutes, 50 km, and 75 km, respectively. The gray shaded and unshaded histograms correspond to the UN and CR time sequences, respectively. The y-axis represents the fraction of UDs in each bin.