Correction of Sensor Alignment of Adeos-ii/gli

The Advanced Earth Observing Satellite (ADEOS)-II was successfully launched in December 2002 by Japan Aerospace and Exploration Agency (JAXA: former NASDA). The Global Imager (GLI) onboard the ADEOS-II is an optical mechanical scanner with 36 channels and the spatial resolution of 1 km and 250m at nadir. It observes about 1,600km in width with the FOV of +/-45 degrees. The same areas are observed every 4 days. JAXA has conducted the initial checkout of GLI image properties just after the launch of the satellite. In the checkout activities, the absolute geometric accuracy was examined. The accuracy was evaluated utilizing ground control point(GCP)s which were automatically extracted by the template matching between GLI image chips and coastline database. The examination for many images showed the geometric accuracy was about a few kilo-meters on the ground. Most of the errors were static, in other words, every image has the almost same geometric errors in both amplitude and direction. Such error patterns were seemed to be induced by the miss-alignments of the GLI sensor. The authors corrected the alignments of the GLI sensor based on the collinearity condition in the photogrammety. After the correction, the geometric accuracy was improved to about one pixel even in 250m channel images. * Corresponding author.