Figure 5. Predictive accuracy of AOD retrievals from Landsat imagery against ground-based measurements at the individual-site scale from 2013 to 2022 using the spatiotemporally independent validation approach (i.e., data samples from the years 2015 to 2020 for training and other years for testing): (a) correlation coefficient (R), (b) median bias, (c) mean absolute error (MAE), (d) root-mean-square error (RMSE), and the percentages of retrievals falling within the (e) expected error envelope (= EE) of the MODIS Deep Blue product and (f) the goal uncertainty defined by the Global Climate Observing System (GCOS).
Table 2. Predictive accuracy of AOD retrievals from Landsat imagery in specific continental regions of interest and on a global scale using the spatiotemporally independent validation approach, i.e., data samples from the years 2015 to 2020 for training and other years for testing.