Table 2. The difference between the GLOBE at Night observations and the values predicted by the fit to the DMSP data are shown for different selections of the GLOBE at Night data. In each case, the number of unique locations sampled, mean value, and standard deviation of the data from the prediction (S_R) are shown. The data are alternatively broken down by the two week period in which they were acquired (top), or by the total number of observations (obs) at a single location (bottom).

Dataset	Unique locations	Mean	SR
2009–2011	13891	0.00	1.06
2009 Mar	3530	0.07	1.11
2010 Mar	3600	0.14	1.13
2011 Feb–Mar	2827	−0.17	0.96
2011 Mar–Apr	1146	−0.41	1.27
2012 Jan	794	−0.09	1.16
2012 Feb	706	−0.15	1.10
2012 Mar	1057	0.00	1.16
2012 Apr	746	−0.28	1.38
1 obs	13621	−0.03	1.13
2 obs	2390	0.02	0.99
3–6 obs	1825	−0.06	0.94
7–12 obs	417	−0.15	0.85
13–20 obs	110	−0.07	0.57
21–30 obs	41	−0.06	0.54
>30 obs	50	−0.06	0.45