  Fourier domain methods are fast algorithms for SAR imaging. They typically
involve an interpolation in the frequency domain to re-grid non-uniform data so
inverse fast Fourier transforms can be performed. In this paper, we apply a
frame reconstruction algorithm, extending the non-uniform fast Fourier
transform, to stripmap SAR data. Further, we present an improved thresholded
frame reconstruction algorithm for robust performance and improved
computational efficiency. We demonstrate compelling results on real stripmap
SAR data.
