A Deramp Frequency Scaling Algorithm for Processing Space-Borne Spotlight SAR Data

Abstract

Reduced the data rate is one of the difficulties in high-resolution space-borne spotlight synthetic aperture radar (SAR). Based on Deramp Chirp Scaling (DCS) algorithm and Frequency Scaling (FS) algorithm, a Deramp Frequency Scaling (DFS) algorithm for processing high-resolution space-borne spotlight SAR data is presented. The algorithm stars with raw data dechirped in range. First, the azimuth spectral folding phenomenon is overcome by using azimuth deramp processing. Secondly, the precise Range cell migration correction is achieved by frequency scaling processing and phase compensation. Lastly, the azimuth compression is performed by match filter. Based on the squinted equivalent range model, the complete derivation of the algorithm is presented and the realizing approach is given. Finally, the computer simulation shows the validity of the algorithm. Keywords—synthetic aperture radar; frequency scaling algorithm; high resolution