An extension to range-Doppler SAR processing to accommodate severe range curvature

This paper introduces a novel extension to the range-Doppler algorithm to accommodate the processing of synthetic aperture radar data with severe range curvature. The extension makes an initial correction in the 2-D frequency domain to a reference range, followed by a residual correction in the range-Doppler domain. The extension requires more computation than the standard range-Doppler algorithm, but many elements may be pre-computed and re-used. The focusing improvement with the new extension over conventional range-Doppler processing is demonstrated using simulated airborne VHF SAR data with zero Doppler centroid