Periodic non-uniformly sampled signal reconstruction of FMCW MIMO SAR using fractional fourier transform

Compared to pulse SAR, Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) is much smaller and lighter. To realize the high-resolution wide-swath SAR imaging and greatly reduce the transmitted power restriction for FMCW SAR, Multiple Input Multiple Output (MIMO) technology is used to realize Multiple Azimuth Beams (MAB). However, when the platform velocity deviates from the theoretical speed, the azimuth signals will be periodic non-uniformly sampled, producing ambiguous targets in azimuth direction. In this paper, the FMCW MIMO SAR non-uniformly sampled signal is presented and the periodic non-uniformly sampled signal reconstruction algorithm based on Fractional Fourier Transform (FrFT) is proposed. Finally, simulation results show the effectiveness of the proposed algorithm.