volume | PIER Journals

Abstract

In spaceborne multi-input multi-output synthetic aperture radar (MIMO SAR) ground moving target indication (GMTI), the unknown radial acceleration of a target induces severe Doppler spectral broadening, while mismatched conventional reconstruction filters lead to significant image defocusing. To address these challenges, this paper proposes a novel focused imaging method that seamlessly integrates radial acceleration estimation with reconstruction filter design. This method first adaptively suppresses static background clutter by utilizing the extended multi-channel clutter suppression interferometer (M-CSI) technique. On this basis, the frequency-domain cross-correlation characteristics of time-domain sub-aperture signals recovered via inverse reconstruction filtering are exploited to estimate the target radial acceleration deeply buried in residual clutter. Furthermore, a ratio factor resistant to amplitude interference is constructed to search for the radial velocity. Finally, a reconstruction filter for maneuvering targets is designed using the obtained motion parameters, completing the unambiguous recovery of the original Doppler spectrum and pulse compression focusing. Simulation results demonstrate that the proposed method can estimate the target maneuvering parameters, thereby thoroughly resolving the defocusing and artifact issues.

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Mr. Yingjia Li

Ms. Kunyu Gao