This book began with a determination to present SAR concepts and signal processing techniques unique to spotlight mode and the polar format algorithm. The existing database of technical articles and books on SAR would serve as a background and starting point, allowing the text to concentrate on practical procedures and advanced analyses in the implementation and evaluation of spotlight SAR image formation processing. As often happens, the fleshing out of the details changed and enlarged the scope of the presentation. The authors believe that the final product, with its broader scope, provides detailed insight into spotlight mode, its applications, and its processing algorithms.