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Autofocus technique for ISAR imaging of uniformly rotating targets based on the ExCoV method 被引量:1
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作者 Chengguang Wu Hongqiang Wang +2 位作者 Bin Deng Yuliang Qin wuge su 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期267-275,共9页
The inverse synthetic aperture radar (ISAR) imaging can be converted into a sparse reconstruction problem and solved by the l1norm minimization algorithm. The basis matrix in sparse ISAR imaging is usually characteriz... The inverse synthetic aperture radar (ISAR) imaging can be converted into a sparse reconstruction problem and solved by the l1norm minimization algorithm. The basis matrix in sparse ISAR imaging is usually characterized by the unknown rotation rate of a moving target, thus the rotation rate and the sparse signal should be jointly estimated. Especially due to the imperfect coarse motion compensation, we consider the phase error correction problem in the context of the sparse signal reconstruction. To address this issue, we propose an iterative reweighted method, which jointly estimates the rotation rate, corrects the phase error and reconstructs a high resolution ISAR image. The proposed method gives a gradual and interweaved iterative process to refine the unknown parameters to achieve the best sparse representation for the ISAR signals. Particularly, in ISAR image reconstruction, the l1norm minimization algorithm is sensitive to user parameters. Setting these user parameters are not trivial and the reconstruction performance depends significantly on their choices. Then, we consider an expansion-compression variance-component (ExCoV) based method, which is automatic and demands no prior knowledge about signal-sparsity or measurement-noise levels. Both numerical and electromagnetic data experiments are implemented to show the effectiveness of the proposed method. It is shown that the proposed method can estimate the rotation rate and correct the phase errors simultaneously, and its superior performance is proved in terms of high resolution ISAR image. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Error compensation Error correction Errors Image processing Image reconstruction Inverse problems Inverse synthetic aperture radar Iterative methods Motion compensation Numerical methods Rotation Signal reconstruction Synthetic aperture radar
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Hybrid micromotion-scattering center model for synthetic aperture radar micromotion target imaging 被引量:1
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作者 Yuliang Qin Bin Deng +1 位作者 Zonghui Huang wuge su 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第6期931-937,共7页
Micromotion is an important target feature, although the target micromotion has an unfavorable influence on the synthetic aperture radar (SAR) image interpretation due to defocusing. This paper introduces micromotio... Micromotion is an important target feature, although the target micromotion has an unfavorable influence on the synthetic aperture radar (SAR) image interpretation due to defocusing. This paper introduces micromotion parameters into the scattering center model to obtain a hybrid micromotion-scattering center model, and then proposes an optimization algorithm based on the maximal likelihood estimation to solve the model for jointly obtaining target motion and scattering parameters. Initial value estimation methods using targets' ghost images are then presented to guarantee the global and fast convergence. Simulation results show the effectiveness of the proposed algorithm especially in high precision estimation and multiple targets processing. 展开更多
关键词 synthetic aperture radar (SAR) MICROMOTION microDoppler parameter estimation scattering center model
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