A comparison of the effectiveness of 6S and SMAC in correcting for atmospheric interference of meteosat second generation images

Abstract

Atmospheric perturbations are a large source of uncertainty in remotely sensed imagery of the Earth's surface. This paper explores the effectiveness of the simplified method for atmospheric correction (SMAC) in reducing the effects of these perturbations in images of the African Continent gathered by the Spinning Enhanced Visible & InfraRed Imager (SEVIRI) aboard Meteosat Second Generation (MSG). In order to examine the accuracy of the SMAC we compare its results to those computed by the Second Simulation of the Satellite Signal in the Solar Spectrum (6SV1.1), a highly accurate radiative transfer code, for a wide range of atmospheric conditions. We find that the SMAC does not offer a high level of accuracy under many sets of atmospheric conditions with under 20% of observations in channels 1 and 2 providing a relative error of less than 10% when compared to 6SV1.1. Those observations involving medium-to-high solar or viewing zenith angles (greater than 40°) or in areas with a high ozone or water vapor content (greater than 0.2 cm/atm and 1.5 gm/cm 2 for ozone and water vapor respectively) returning a particularly high relative error. Nevertheless, as the SMAC is up to 3000 times faster in processing a SEVIRI scene than 6SV1.1 it is still a useful atmospheric correction tool, particularly as a majority of the differences between the SMAC and 6S appear straightforward to correct for. © 2010 by the American Geophysical Union.