Sparsity-Driven Radar Imaging Using Two-Step OMP With a Unified Rectangular Plate Model

Traditional radar imaging methods based on point target models fail to achieve ideal results for extended targets, while simultaneously using multiple models introduces redundancy. This letter first treats point targets and line segments as special cases of rectangular plate targets, unifying the three target types under a single scattering model based on rectangular plates. Subsequently, a two-step orthogonal matching pursuit (OMP) algorithm is proposed to achieve sparsity-driven radar imaging. In the first OMP step, an observation matrix is constructed using the ideal point target model and the observation geometry, enabling coarse estimation of target position parameters in a greedy manner. In the second step, a unified rectangular plate model is employed along with the positional information obtained from the first OMP step to reconstruct the observation matrix. This allows for the simultaneous greedy estimation of both the rectangular plate model parameters and positional parameters, thereby reconstructing the target structure. Finally, the effectiveness of the proposed algorithm is validated through simulated experiments and real anechoic chamber tests.