ASTER geometric performance

The ASTER system is flying on the Terra spacecraft since December 18, 1999. After the instrument check, multispectral images ranging from visible to thermal infrared have been provided using three subsystems, i.e., VNIR, SWIR and TIR. To deliver data products with high quality from the viewpoint of the geolocation and band-to-band registration performance, the fundamental program called the Level-1 processing has been developed. On December 1, 2000, the official data products (Version 1.0) were released, where the band-to-band registration accuracy in the subsystem was better than 0.3 pixels and that between subsystems was better than 0.5 pixels. On May 1, 2001, the validated data products have been released by improving the geometric performance, where the band-to-band registration in the subsystem is better than 0.1 pixels and that between subsystems is better than 0.2 pixels. In this paper, the characteristics of the images and the effect of geometric parameters on the image quality of the ASTER system, which consists of four telescopes and a cross-track pointing function, are analyzed by image matching method based on a cross-correlation function.