Sparse passive radar imaging based on FM stations using the U-ESPRIT for moving target

This paper studies the passive radar imaging system based on Frequency Modulated (FM) stations. Firstly, we establish the imaging model for moving target which consists of multiple FM stations and one receiver. Although movement information brings improvement of resolution, similarly to ISAR, but the shortage of wavenumber domain filling also causes the failure in imaging under little stations condition, so we consider using the sparse recovery techniques to realize imaging. However, in actual radar system, some previous CS methods probably suffer from off-grid point effect, which causes performance degradation of the methods. Therefore, based on the theories of Xampling and the finite rate of innovation (FRI), we propose a high-resolution sparse imaging method to overcome the problems stated above, which utilizes the unitary estimating signal parameters through rotational invariance techniques (U-ESPRIT) and the cross point searching technique (CPST). Simulation results show the effectiveness of the proposed method and the related analysis.