Global imager's onboard calibration (VNIR-SWIR)

The whiskbroom scanner Global Imager (GLI) will be launched on Advanced Earth Observation Satelite 2 (ADEOS-2). It will provide remotely sensed data from the Earth surface from the visible to the thermal infrared. Since the Earth observation data require a careful 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 a calibration strategy is presented to achieve a high calibration accuracy of the remotely sensed data by means of solar calibration. Therefore the theoretical background, the performed hardware characterization and applied external data basis are presented. Further on it is shown how a stray light simulation analysis using a non- sequential ray-tracing tool will be used to increase the reliability of the solar calibration.