The utilization of SAR remote sensing and GIS technology to delineate urban extent in North China

Urban environments represent one of the most dynamic regions on earth. In order to obtain more frequently updated and spatially detailed data on urban phenomena, remote sensing satellites can serve as a valuable instrument. With its ability to image the Earth's surface in nearly all weather conditions, together with its high spatial resolution, synthetic aperture radar (SAR) represents a very powerful observation tool for monitoring geophysical resources globally. SAR images with high resolution have proven their usefulness for land description and scene analysis. The goal of this study was the development of a temporally and spatially robust approach towards an automated identification of built-up areas based on RADARSAT imagery. In our work, the urban extent distributed in the major part of North China was extracted and delineated. By visual inspection, the resulting map of urban extent was acceptable.