The principal goal of remote sensing is to interpret the data recorded in order to understand the region being imaged; interpretation can be based on qualitative or quantitative methods of analysis. Analyst expertise allows qualitative information extraction through photointerpretive methods in which visual clues around structure and contrast are used. With knowledge of the radar scattering behaviours of earth surface features, such as treated in Chapt. 5, the analyst can often make very good assessments of the types of land cover being imaged.