ASTER, dati geometrici e generazione di DEM

The images provided by ASTER sensor are used in a large number of applications; the interest for these data doesn’t rely only on their radiometric and multispectral characteristics, but also on the possibility of their use for geometric products, thanks in particular to stereoscopic acquisition. The stereo-couple, realized along-track by two telescopes - nadiral and backward - is in the band 3 (near-infrared, 0.78-0.86 μm), with ground resolution of 15 m and ratio B/H=0.6. In the paper the main geometric characteristics of ASTER images are described, together with principles and procedures for the automatic generation of the digital surface model. The model, of relative or absolute type, can be exploited in a wide spectrum of applications.