Fast corrections for polar format algorithm with a curved flight path

We propose an algorithm for synthetic-aperture-radar image formation with a curved flight path based on the polar-format algorithm that corrects for defocus and distortion observed in images via the polar-format algorithm. Our correction permits application of a single quadratic phase-error correction to an entire range gate before the azimuth fast Fourier transform in the polar format algorithm. Experimental results demonstrate corrections to distortion and defocus with simulated and measured imagery, greatly increasing scene size with few additional computations.