RFI SUPPRESSION BASED ON ATOMIC NORM MINIMIZATION IN SAR SIGNAL RECOVERY

The recovery problem of synthetic aperture radar (SAR) signal in the presence of radio frequency interference (RFI) is studied. To perform RFI suppression, in this paper, the RFI is modeled as the combination of multiple complex sinusoids such that the RFI suppression problem becomes a frequency estimation one. To accurately estimate model parameters, by exploiting sparse representation of the RFI, a gridless approach based on atomic norm minimization is proposed, which completely removes the off-grid issue. Finally, to recover the SAR signal, a joint scheme is devised to simultaneously perform the RFI suppression and the SAR signal recovery under an optimization framework. The resultant optimization is efficiently solved by a two-step process based on the coordinate descent approach. Simulation results and real-world experiments are provided to show the superior performance of the proposed approach.