Fig. 4. The VZA stratified DNB time series (left) and the boxplot of DNB observations of different VZA intervals (right) for the corresponding pixel on the left. The red, green, and blue dots indicate the DNB observations within different VZA intervals. (a) A rural grocery store in Seekonk, MA, U.S.; (b) Downtown Melbourne, Australia; (c) Dense residential area with multi-story buildings, Nahyan, Egypt.