Land cover classification based on single-polarized VHR SAR images using texture information derived via speckle analysis

Speckle is a SAR specific noise effect caused by constructive and destructive interference from multiple scattering within the resolution cell of the imaging radar system that superposes the true radiometric and textural information of SAR images as a grainy `salt-and-pepper´ pattern. Fully developed speckle basically follows circular Gaussian image statistics. However, this assumption is not applicable for very high resolution SAR systems and for data showing sceneries with a significant amount of directional backscatter - e.g. urban areas. In those cases the multiple scattering processes within a resolution cell show - subject to the true structuring of the imaged area - rather a directional behavior than a random distribution. Consequently, the speckle is no longer fully developed. In our study we demonstrate how information on the local development of speckle can be used to differentiate between basic land cover types such as water, open land - meaning farmland, grassland and bare soil -, woodland and urban area in single-polarized, single-date VHR SAR images. The research is based on the analysis of a TerraSAR-X scene of Munich, Germany.