Performance evaluation of MODIS and VIIRS satellite AOD products over the Indian subcontinent

In the present study, first systematic performance evaluation of aerosol optical depth (AOD) products retrieved using two satellite sensors i.e., Visible Infrared Imaging Radiometer Suite (VIIRS) and Aqua-Moderate-Resolution Spectroradiometer (MODIS) is carried out over India. We have used ground-based AOD from AERONET at 550 nm wavelength for inter-comparison with MODIS Aqua version C6.1 (C061) Deep Blue (DB) product VIIRS/SNPP collection 1.1 (V1.1) DB time span 7-year (2014–2020) observation periods. For validation, average value pixels falling within box 50 Km x keeping station center retrieved. The daily data sun photometer (2014–2019) were obtained ±15 min overpass time. Statistical parameters like correlation coefficient (R), RMSE, MAE, RMB calculated. uncertainty evaluated an envelope Expected Error (EE = ±0.05 + 0.15 land). analysis shows that outperforms VIIRS-retrieved AOD. both yields a high (0.86—Jaipur, 0.79—Kanpur, 0.84—Gandhi College, 0.74—Pune 0.75—Jaipur, 0.77—Kanpur, 0.49—Gandhi 0.86—Pune VIIRS) low MAE (0.12—Jaipur, 0.20—Kanpur, 0.15—Gandhi 0.09—Pune 0.13—Jaipur, 0.13—Kanpur, 0.26—Gandhi 0.10—Pune VIIRS). Other statistical measures such as RMB, P also suggest similar performance. More than 66% total fall range EE each station. Spatial comparison exhibits same pattern seasonally well annually having minimum bias −0.3 to +0.3 between VIIRS. Slight underestimation overestimation are observed in all stations by MODIS, whereas VIIRS continuously underestimates increase depth, suggesting improvements model surface reflection retrieval. Overall, ground reveals better accuracy datasets