Fusion of ASTER image data for enhanced mapping of landcover features This paper presents the results of an exercise that involved fusion of VNIR and SWIR images of an area in south India containing the commonly observed land cover features such as water, vegetation (agriculture and forest), various rock types, soil types and built environments. The aim of image fusion here is to integrate complementary data (in VNIR & SWIR) in order to obtain more information than cannot be derived from single sensor data alone. This is an unique attempt in the sense that this is probably haps the first study in India that has attempted to use the image data obtained from the ASTER sensor.  Fig 2: SWIR Image data and study area The digital image data used in the study has been obtained by the ASTER sensor. ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument on board TERRA -1, a satellite launched in December 1999 as part of NASA’s Earth Observing System (EOS). ASTER is used to obtain detailed maps of land surface temperature, emissivity, reflectance and elevation and is a suite of three high-performance optical radiometers with 14 spectral channels (Table.1), that contribute valuable scientific and operational data on the earth. It is designed to meet the mission requirements of operational users and scientific researchers in the visible and near infrared (VNIR) the short wavelength infrared (SWIR) and the thermal infrared (TIR). The major features of ASTER are : (i) Simultaneous earth surface images from the visible to the thermal infrared, (ii) Higher geometric and radiometric resolution in each band than current satellite sensors, (iii) Near infrared stereoscopic image pairs collected during the same orbit, (iv) Exquisite optics that allow the instrument axis to move as much as +- 24 degrees for SWIR and TIR cross-talk direction from the nadir, and (v) Highly reliable cryocoolers for the SWIR and TIR sensors  Fig 3(a): Fused Image PCA |