Image Fusion of RISAT-1 SAR Backscattered Image with AWiFS Optical Data

Abstract

Synthetic Aperture Radar (SAR) imaging is independent of solar illumination and cloud cover. The interpretability of optical images is improved by fusing with SAR images. The pixel intensity values of SAR image are often converted to physical quantity called backscattering coefficient measured in dB. It is an important property of SAR which is used to differentiate among the land surfaces. Hence, converting SAR image to backscattered image using backscattering coefficient provides more information compared to SAR image. SAR images are captured in four polarization modes. HH and VV polarization modes provide information of smooth surface and water bodies while HV and VH polarization modes provide information of vegetation and crop. In this paper, fusion of backscattered image in HH and HV polarization mode with optical image is carried out. Product from RISAT-1 and AWiFS are used for fusion.