3-D MIMO radar imaging of ship target with rotational motions

Abstract

The problem of image defocusing and distortion occurs in synthetic aperture radar (SAR) imaging of ship target with rotations. Although many literatures have analyzed this problem, it cannot efficiently be solved due to the coherent accumulation time for SAR target imaging, which results from their working principle and mechanism. In this paper, three-dimensional MIMO radar imaging of ship target with rotations is proposed. The real-time advantage of MIMO radar imaging is utilized to achieve high-precision imaging of ship target with rotations. Firstly, the ship rotations characteristics and imaging distortion effects are analyzed in detail. Then, the three-dimensional MIMO radar echo model is built to correct the scattering positions in time, geometrical analysis is carried out to analyze and optimize the target scattering coefficient variation process. Finally, a sparse imaging algorithm based on maximum a posterior (MAP) method is proposed to obtain accurate imaging result. Theoretical analysis and simulation results show that the three-dimensional imaging of ship target based on MIMO radar has better imaging accuracy and real-time performance compared with SAR, and can effectively solve the problem of image defocusing and distortion.