Improved estimation of insolation by using calibrated COMS MI images over South Korea

In this study, a correction function based on a comprehensive vicarious calibration was applied to Communication, Ocean and Meteorological Satellite (COMS) and Meteorological Imager (MI) visible channel for improving the estimate of insolation. The COMS MI visible channel was calibrated by using natural targets such as ocean, desert, water cloud and deep convective cloud, which are carefully selected due to their theoretical reference reflectance. Based on calibration with four targets, the corrected COMS MI visible channel is used as an input parameter of an insolation physical model, especially for interpreting cloud effects. Results showed that corrected insolation has better accuracy than previous methods for cloudy conditions. Seasonal bias of insolation, which generally has the worst accuracy in a cloudy summer period, is improved by using calibrated COMS MI visible data.