Autofocus of sparse microwave imaging radar based on phase recovery

Sparse microwave imaging radar is a newly developed concept of microwave imaging, which introduces the sparse signal processing theory to traditional microwave imaging. As a combination of sparse signal processing theory and microwave imaging, the sparse microwave imaging is attracting people´s interest for its several potential advantages including better imaging performance and lower system complexity requirement. Airborne platform is an important application platform of sparse microwave imaging radar. On the airborne platform, the effect of motion phase error must be considered. Autofocus is an important technology to deal with the phase error in radar imaging, while traditional autofocus algorithms could not be directly applied under the sparse microwave imaging framework. In this paper, we introduce the phase recovery problem in the sparse signal processing theory to sparse microwave imaging, develop a novel autofocus algorithm under the sparse microwave imaging framework based on phase recovery. The phase recovery problem is solved via a greedy algorithm. A simulation is provided to demonstrate the effectiveness of the suggested algorithm.