Recent Activities and Advances of GOCI Data Processing System

Abstract

Geostationary Ocean Color Imager (GOCI) is the world-first ocean monitoring sensor in geostationary orbit. GOCI data processing system (GDPS) has developed from 2003 as a basic data processing software for GOCI. The GDPS generates the level 2 and the level 3 data from the level 1B data which is an output file of the IMPS (Image pre-processing system) in HDF-EOS5 format. Cloud detection, atmospheric correction and bi-directional reflectance distribution function (BRDF) correction are the first mandatory steps of the GDPS to retrieve an ocean signal reflected above the ocean surface. The GDPS could generate numerous level 2 ocean products applied its specific local/global algorithm. Furthermore, it could generate the Level 3 accumulated data, secondary derived products and some auxiliary parameters for GOCI operation.The GDPS has been modified to apply new/updated algorithm and to process acquired real data. To improve integrity of the system, it was verified that the algorithms, source codes and working conditions were enough to operate correctly.The level 1B file is an input of the GDPS, and acquiring good quality of the Level 1B file is the most important task. Nevertheless, several discrepant problems were found between each slot in Level 1B. To solve this slot discrepancy problem, we compare slot images each other in the overlap region. We try to discover various relations on the level 1B data and a daily variation pattern. We consider the solar irradiance change by daily solar movement and miss-matching of geometric correction as the reason of this problem. The GDPS will be updated continuously for algorithm updates, addition of new products and the user comport usage of this system.