Extended Chirp Scaling Algorithm for Spotlight SAR

Among Synthetic Aperture Radar (SAR) image formation algorithms, the chirp scaling algorithm (CSA) is computationally highly efficient and has been practically used. In this paper, how to implement the subaperture extended CSA in a high resolution spotlight mode SAR is studied in detail. The procedures such as subaperture processing and azimuth processing are discussed. According to the problems presented when using the method (A. Moreira, et al, 1996) to process spotlight SAR data, full formula expressions suitable for high squinted angles is presented. While point target simulation is analyzed, the method is validated by E-SAR raw data. The results can be directly implemented in the design of SAR processors.