Cross-calibration of GOCI and GOCI-II TOA Radiation Data

Abstract

Degradation of satellite sensor sensitivity may occur due to aging of sensors. Since this affects the accuracy of atmospheric correction and the trend of long-term monitoring of marine environmental variables, it is necessary to continuously update the radiation correction coefficient considering sensor degradation using sunlight or moonlight. In this study, we used Geostationary Ocean Color Imager (GOCI) and GOCI-II top of atmosphere(TOA) data. GOCI-II, the follow-up satellite sensor of GOCI, was launched in February 2020 and has been observing Northeast Asia and the full disk area. Currently, there are errors in the calculation of the flag value of the GOCI-II sensor due to a calibration problem. Therefore, we studied calibration method to improve the quality of TOA radiance in near infrared band data. And degradation calibration model was developed and applied to the GOCI-II data by analyzing the solar diffuser data accumulated since the launch of the GOCI-II. We used GOCI data for cross-calibration.