Assessment of GOCI Atmospheric Correction for Observing a Diurnal Variation of Ocean Color

Abstract

The Geostationary Ocean Color Imager (GOCI) observes the Northeast Asia ocean environment including the Korean Peninsula, and it provides hourly diurnal ocean color data from the geostationary orbit. Atmospheric correction is an essential process for the satellite ocean color remote sensing that determines the reliability of the data quality. The stability of the atmospheric correction for various solar angles is further required for the diurnal observation, especially. Small input errors in the atmospheric correction process can significantly cause the diurnal instability of result accuracy.In the study, we first analyze that how the GOCI atmospheric correction is sensitive to the uncertainties along various solar angles through simulations. Various atmospheric radiances regarding directional effect is simulated by radiative transfer code to see the sensitivity. Then the uncertainty of remote-sensing reflectance (Rrs) resulted by the atmospheric correction is compared with the in situ diurnal variabilities of Rrs to what extent GOCI detect the diurnal changes in the marine environment.rocess for the satellite ocean color remote sensing that determines the reliability of the data quality. The stability of the atmospheric correction for various solar angles is further required for the diurnal observation, especially. Small input errors in the atmospheric correction process can significantly cause the diurnal instability of result accuracy.In the study, we first analyze that how the GOCI atmospheric correction is sensitive to the uncertainties along various solar angles through simulations. Various atmospheric radiances regarding directional effect is simulated by radiative transfer code to see the sensitivity. Then the uncertainty of remote-sensing reflectance (Rrs) resulted by the atmospheric correction is compared with the in situ diurnal variabilities of Rrs to what extent GOCI detect the diurnal changes in the marine environment.