Three-year operation of in-orbit radiometric calibration for geostationary ocean color imager

Abstract

Geostationary Ocean Color Imager (GOCI) onboard COMS(Communication, Ocean and Meteorological Satellite) spacecraft is the first spaceborne imager for ocean color remote sensing in Geostationary Earth Orbit (GEO). Over the three years, GOCI has been in on-orbit normal operation since its launch in June 2010. For the fulfillment of ocean color monitoring mission, GOCI equips 8 spectral bands. In visible wavelength region from 40 2nm to 685 nm, 6 spectral bands are implemented on GOCI with the bandwidth of 20 nm (for B1 ~B5) or 10 nm (for B6, central wavelength at 680 nm). Two spectral bands located in NIR wavelength region with band center at 745nm and 865 nm are mainly used for the atmospheric correction. Thanks to the satellite location in geostationary orbit, GOCI can acquire the image from Earth with staring capture method with 2D CMOS FPA (Focal Plane Array). Instantaneous Field of View(IFOV) of GOCI is about 700 km x 700 km with 500 m spatial resolution over the center of the coverage area (130˚E, 36˚N). Because the userrequired observation coverage area is 2,500 km x 2,500 km which includes the region of Korean Peninsula, East China, and Japan, 4 x 4 slot image acquisitions which corresponds to IFOV are required for the image acquisition for the coverage area including overlap region among slot images. In-orbit calibration activities of GOCI have mainly been performed using onboard SolarOCI has been in on-orbit normal operation since its launch in June 2010. For the fulfillment of ocean color monitoring mission, GOCI equips 8 spectral bands. In visible wavelength region from 40 2nm to 685 nm, 6 spectral bands are implemented on GOCI with the bandwidth of 20 nm (for B1 ~B5) or 10 nm (for B6, central wavelength at 680 nm). Two spectral bands located in NIR wavelength region with band center at 745nm and 865 nm are mainly used for the atmospheric correction. Thanks to the satellite location in geostationary orbit, GOCI can acquire the image from Earth with staring capture method with 2D CMOS FPA (Focal Plane Array). Instantaneous Field of View(IFOV) of GOCI is about 700 km x 700 km with 500 m spatial resolution over the center of the coverage area (130˚E, 36˚N). Because the userrequired observation coverage area is 2,500 km x 2,500 km which includes the region of Korean Peninsula, East China, and Japan, 4 x 4 slot image acquisitions which corresponds to IFOV are required for the image acquisition for the coverage area including overlap region among slot images. In-orbit calibration activities of GOCI have mainly been performed using onboard Solar