The Global Imager (GLI) on Advanced Earth Observing Satellite-II (ADEOS-II) launched on 14 December 2002 is an optical sensor to observe reflected solar radiation and infrared radiation. GLI has 36 channels from ultraviolet region (380nm) to thermal infrared (12micron). GLI data is used for understanding the global circulation of carbon, monitoring cloud, snow, ice, and sea surface temperature. NASDA carried out initial checkout to confirm GLI basic function until April 2003. Currently GLI calibration team that consists of sensor development division, ground system integration division, and science application group analyses calibration and validation to release L1 data at the end of this year. This report describes calibration and instrument status of GLI.
The whiskbroom scanner Global Imager (GLI) was launched in December 2002 on the Advanced Earth Observation Satellite 2 (ADEOS-2). The sensor provides remotely sensed data from the Earth surface in the visible to the thermal infrared part of the spectrum. Since the Earth observation data require careful post-launch calibration, different on-board calibration tools have been integrated in the GLI hardware design. For the VIS-SWIR spectral range a special calibration device allows solar and lamp calibration. In this paper we describe first results on solar calibration of GLI.
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.