NUFFT applied to motion compensation in the Near-Space SAR imaging

Non-uniform FFT (NUFFT) algorithm is widely applied to Communication, Medical Imaging, Radio Astronomy and so on. NUFFT contributes to SAR imaging and Near-Space SAR also becomes popular recently years. It is difficult to get accurate SAR image in Near-Space because of the obvious motion error and Wide-Swath when the vehicle is slow, so we propose an approach which uses twice NUFFT in ω - k algorithm to solve the problem in this paper. The first NUFFT can solve non-uniform sampling along the track, the second NUFFT can replace the Stolt interpolation and the final range inverse FFT in ω - k algorithm to increase the computational efficiency without reducing the accuracy of the SAR image. The new method is especially suited for Near-Space SAR imaging when the speed of the vehicle is slow.