Latest atmospheric correction algorithm updates for the operational GOCI-II data processing system

Abstract

Atmospheric correction is a necessary process in ocean color remote sensing that estimates the water reflectance at the sea surface from the top-of-atmosphere. This study describes the updated features in the current atmospheric correction and its validation results for the second Geostationary Ocean Color Imager (GOCI-II). The GOCI-II atmospheric correction is theoretically based on the SeaWiFS method, then partially modified in terms of using the more direct aerosol reflectance estimation method and employing the more robust NIR water reflectance model for turbid waters. The current updates focus on the sensor's radiometric degradation correction and the vicarious calibration gains adjustment. The improved atmospheric correction is validated with in-situ radiometric data collected from several cruises and AERONET-OC sites. The updated atmospheric correction has been implemented in the GOCI-II Ground Segment since October 2023.