RADIOMETRIC CALIBRATION AND VALIDATION PLAN OF GEOSTATIONARY OCEAN COLOR IMAGER (GOCI)

Abstract

Geostationary Ocean Color Imager (GOCI) is the first ocean observation imager in geostationary orbit,and it is one of the three main payloads in Communication, Ocean and Meteorological Satellite (COMS)which is scheduled to be launched in 2009. In 2003, by the request of Korea Ocean Research &Development Institute (KORDI), Republic of Korea determined to develop the GOCI. Ministry of Land,Transport and Maritime Affairs (MLTM) sponsored the GOCI which was co-developed by KoreaAerospace Research Institute (KARI) and EADS Astrium. Korea Ocean Satellite Center (KOSC) inKORDI is the main operation center of the GOCI, and has responsibility of the GOCI data processingand distribution.In order to provide the monitoring capability in coastal zone where the biophysical phenomena varyingon smaller space and shorter time scales demand a simultaneous increase in spatial and temporalresolution, the GOCI designed and developed with eight visible-to-near-infrared bands, a 500m×500mpixel resolution, and a coverage region of 2500km×2500km centered at 36°N and 130°E. Because theGOCI implemented a 2D staring-frame image capture system, the GOCI Image with full coverageconsists of 16(4x4) slots. The GOCI planned to observe the full coverage region by every hour indaytime, and provide 8 images in daytime during single day. The life time of the GOCI mission is about7.7 years.Solar calibration is the in-orbit radiometric calibration method of the GOCI. QVD (Quasi VolumeDiffuser) type Solar Diffuser and Diffuser Aging Monitoring Device (DAMD) are equipped in the GOCIas the on-board calibrators. Solar Diffuser and DAMD are identical except for the size. The GOCI ongroundcalibration and characterization were performed by EADS Astrium and KARI. KORDI hasselected “Thuillier 2004 spectrum”[1] as a reference solar irradiance model of the GOCI[2] and developthe enhanced solar irradiance model taken into account the solar irradiance variation due to S