A Discussion of Digital Processing in Synthetic Aperture Radar

This is a summary paper describing the processing of synthetic aperture radar (SAR) data using digital correlation algorithms. Fundamental SAR theory as it applies to the various SAR modes, namely, strip mapping, spotlight mapping, and Doppler beam sharpened mapping, is described and a baseline design applicable to all SAR modes is presented. Digital processor design is developed, starting with a simple single filter mechanization and proceeding through more complex processing algorithms. Prefilter design is discussed, as is the more advanced processing algorithms, namely, multiple parallel prefilters, two-stage correlation, and FFT processing. The primary processor tradeoff is increased functional complexity versus reduced arithmetic and memory requirements. For high-resolution applications, the arithmetic requirements can be reduced by an order of magnitude or more by implementing the more advanced processing algorithms.