In-orbit solar diffuser characterization for radiometric calibration of geostationary ocean color imager

Abstract

ocean color observation satellite in geostationary orbit. GOCI was developed to accomplish the ocean monitoring mission of Communication, Ocean and Meteorological Geostationary Ocean Color Imager(GOCI) is the world’s fi rst Satellite(COMS). In June 2010, COMS is scheduled to be launched at Kourou SpaceCenter in French Guiana by Ariane 5 ECA Launch Vehicle. After successful launch, in-orbit test of GOCI are conducted by Korea Ocean Satellite Center(KOSC) in KORDI, Korea Aerospace Research Institute(KARI), and EADS Astrium in France.Solar calibration which uses sun as a reference light source is GOCI in-orbit calibration method. For the degradation monitoring of Solar Diffuser(SD) due to solar UV radiation, galactic cosmic rays and space debris, 2nd diffuser, DAMD(Diffuser Aging Monitoring Device) is also equipped in the GOCI. The SD and DAMD of GOCI are sameQVD(Quasi Volumic Diffuser) type which were made of fused silica. Diameter of the SD and DAMD is 14cm, 7cm respectively. Because in-orbit calibration method of GOCI is solar calibration, in-orbit characterization of Solar Diffuser(SD) and Diffuser AgingMonitoring Device(DAMD) during In-Orbit Test(IOT) period is planned for the determination of initial diffusion factor for the nominal GOCI radiometric calibration operation. In this paper, we present the characterization result of SD and DAMD for GOCI in-orbit solar calibration.