정지궤도 해양위성(GOCI)의 궤도상 광학성능 및 복사보정 예비시험 결과

Abstract

Geostationary Ocean Color Imager (GOCI) is the one of the three main payloads in Communication, Ocean and Meteorological Satellite(COMS), and it was successfully co-developed by Korea Aerospace Research Institute (KARI) and EADS Astrium in France by the request of the Korea Ocean Research & Development Institute (KORDI). COMS is planned to be launched at Kourou Space Center in French Guiana by Ariane 5 Launch Vehicle in April 2010. After the successful launch, Nominal GOCI Operation including In-Orbit Tests is under the responsibility of the Korea Ocean Satellite Center(KOSC) in KORDI. As the worlds 1st ocean color observation satellite in geostationary orbit, the GOCI has been developed with eight visible-to-near-infrared bands, a 500m×500m pixel resolution in the center of the GOCI coverage area. The size and location of the GOCI coverage area is the 2,500km×2,500km square centered at 36˚N and 130˚E. Geostationary orbit effectively enables to implement 2d staring-frame capture design. Due to the limited IFOV of the GOCI CMOS FPA, the GOCI coverage area is covered by the 16(4x4) slot images. GOCI IFOV corresponds to the FOV of the GOCI slot area. The GOCI also has been developed to observe the GOCI coverage area by every hour and planned to observe and transmit 8 GOCI coverage area images per day. The mission life time of the GOCI is about 7 years.The GOCI in-orbit calibration method is the solar calibration. In order to monitor the degradation of transmittance of solar diffuser, 2nd diffuser, DAMD(Diffuser Aging Monitoring Device) is also equipped in the GOCI. The SD(Solar Diffuser) and DAMD of the GOCI are identical but size. Diameter of the SD and DAMD is 14cm, 7cm respectively. The SD and DAMD are QVD(Quasi Volume Diffuser) type diffuser made of Fused Silica. In this paper, we present the preliminary characterization result of GOCI in-orbit solar calibration operated at in-orbit test period.