title: Sparse Auto-Calibration for Radar Coincidence Imaging with Gain-Phase Errors.
abstract: Radar coincidence imaging (RCI) is a high-resolution staring imaging technique without the limitation of relative motion between target and radar. The sparsity-driven approaches are commonly used in RCI, while the prior knowledge of imaging models needs to be known accurately. However, as one of the major model errors, the gain-phase error exists generally, and may cause inaccuracies of the model and defocus the image. In the present report, the sparse auto-calibration method is proposed to compensate the gain-phase error in RCI. The method can determine the gain-phase error as part of the imaging process. It uses an iterative algorithm, which cycles through steps of target reconstruction and gain-phase error estimation, where orthogonal matching pursuit (OMP) and Newton's method are used, respectively. Simulation results show that the proposed method can improve the imaging quality significantly and estimate the gain-phase error accurately.
authors.affiliation: School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. zhouxiaoli@nudt.edu.cn.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhou
authors.affiliation: School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. oliverwhq1970@gmail.com.
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. nudtyqcheng@gmail.com.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China. yuliang.qin@gmail.com.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Qin
keywords: auto-calibration; gain-phase error; orthogonal matching pursuit (OMP); radar coincidence imaging (RCI); sparse recovery