An approach for refocusing of ground fast-moving target and high-order motion parameter estimation using Radon-high-order time-chirp rate transform

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• 作者：Penghui Huang ; ^{huangpenghuixidian@163.com" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Guisheng Liao ^{liaogs@xidian.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Zhiwei Yang ^{yangzw@xidian.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Jingtao MaAuthor Vitae
• 关键词：Synthetic aperture radar (SAR) ; Ground moving target imaging (GMTIm) ; Motion parameter estimation ; Third-order Doppler broadening ; High-order time-chirp rate transform (HTRT)
• 刊名：Digital Signal Processing
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：48
• 期：Complete
• 页码：333-348
• 全文大小：4073 K

文摘

Long synthetic aperture time can improve the imaging quality of a ground moving target, whereas a moving target may be severely smeared in the cross-range image due to the range migration and the Doppler frequency migration. In this paper, the effects of the third-order Doppler broadening and Doppler ambiguity of a fast-moving target are considered. To address these issues, a novel motion parameter estimation method named high-order time-chirp rate transform (HTRT) is proposed, and then a new synthetic aperture radar (SAR) imaging method based on Radon-HTRT (RHTRT) for a ground moving target is developed. The major contributions are as follows: 1) The proposed SAR imaging method can eliminate the Doppler ambiguity effect. 2) The proposed method can realize longer time coherent integration than Radon–Fourier transform (RFT) and Radon–fractional Fourier transform (RFRFT) methods. 3) The proposed method is computationally efficient since HTRT can obtain the motion parameters of a moving target via performing the 2-dimensional (2-D) fast Fourier transform (FFT). Both the simulated and real data processing results show that the proposed method can finely image a ground moving target in a high signal-to-clutter and noise ratio (SCNR) environment.