GLI early calibration results for oceanographic applications

The Advanced Earth Observing Satellite-II (ADEOS-II) was launched on 14 December 2002, and its functions were checked until 2003 spring. The Global Imager (GLI) on board ADEOS-II has 36 channels (thirty 1-km resolution, six 250-m resolution) from ultraviolet to thermal infrared to facilitate understanding the global environmental changes in oceans, land and clouds with high accuracy. Ocean algorithms (e.g., ocean atmospheric correction and sea-surface temperature) need highly accurate sensor characterization coefficients because they retrieve sea-surface upward radiance precisely from the top of the atmosphere. The NASDA GLI calibration team includes members of sensor development, ground system integration, and science application groups. The team started investigating GLI characteristics and radio- and geo-correction processes in the initial verification period. In this paper, we will describe the initial results, radiometric accuracy, 12- or 48-detector dependency, scan-mirror surface, incident-angle dependency, and dynamic range related to oceanographic applications.