An Adaptively Weighted Least Square Estimation Method of Channel Mismatches in Phase for Multichannel SAR Systems in Azimuth
An Adaptively Weighted Least Square Estimation Method of Channel Mismatches in Phase for Multichannel SAR Systems in Azimuth
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DOI：
10.1109/lgrs.2013.2264771
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发表时间：
2014-02
影响因子：
4.8
通讯作者：
Yanyang Liu;Zhenfang Li;Taoli Yang;Z. Bao
中科院分区：
文献类型：
--
作者：
Yanyang Liu;Zhenfang Li;Taoli Yang;Z. Bao
多通道合成孔径雷达（SAR）系统在方位角上可以实现高分辨率和宽波段成像。然而，信道相位失配会增加处理后多普勒带宽（PDB）外的能量，从而降低最终SAR图像的质量。为了解决这个问题，本文提出了一种通过最小化PDB外能量的校准算法。理论分析表明，该方法可以理解为一个自适应加权最小二乘估计问题，其权重与不同方向回波的信噪比有关。仿真结果表明，该方法在准均匀采样情况下优于传统方法，特别是在低信噪比区域。
Multichannel synthetic aperture radar (SAR) systems in azimuth can achieve high-resolution and wide-swath imaging. However, the quality of final SAR image can be degraded by the channel mismatch in phase which increases the energy outside the processed Doppler bandwidth (PDB). To address this problem, a calibration algorithm is proposed in this letter by minimizing the energy outside the PDB. Theoretical analysis shows that the presented method can be interpreted as an adaptively weighted least square estimation problem, where the weights are related to the signal-to-noise ratio (SNR) of the echoes from different directions. Simulation results reveal that our method outperforms the conventional methods in the case of quasi-uniform sampling, particularly at the low-SNR region.