Robust Channel Mismatch Estimation in Multichannel HRWS SAR Based on Range Spectrum Analysis
FANG Chao① LIU Yanyang② SUO Zhiyong① LI Zhenfang① CHEN Junli③
①(National Laboratory of Radar Signal Processing, Xidian University, Xi’an 710071, China) ②(Shanghai Institute of Satellite Engineering, Shanghai 201109, China) ③(Shanghai Academy of Space Technology, Shanghai 201109, China)
Abstract：In multichannel High-Resolution and Wide-Swath (HRWS) Synthetic Aperture Radar (SAR) systems, channel amplitude and phase mismatches would degrade the performance of azimuth ambiguity suppression as well as range sampling mismatches. To address this problem, a robust estimation method based on range spectrum analysis is proposed in this letter. The method includes two steps: firstly, by exploiting the interferometric phases between the range spectrums of adjacent channels, the proposed method can robustly estimate range sampling mismatches by the combination of phase unwrapping and a weighted least squares fitting. Secondly, based on the theory of spatial cross correlation, an accurate Doppler centroid and phase mismatches could be obtained from constant phases between adjacent channels. Compared with traditional methods, the proposed method overcomes the effect of phase wraps and jumps on polynomial coefficient estimation. It not only improves the robustness of parameter estimation but also can simultaneously obtain the Doppler centroid and phase mismatches. Experimental results based on airborne real data and simulated data validate its effectiveness of the proposed method.
房超,刘艳阳,索志勇,李真芳,陈筠力. 基于距离谱分析的方位多通道HRWS SAR通道偏差稳健估计[J]. 电子与信息学报, 2018, 40(7): 1561-1566.
FANG Chao, LIU Yanyang, SUO Zhiyong, LI Zhenfang, CHEN Junli. Robust Channel Mismatch Estimation in Multichannel HRWS SAR Based on Range Spectrum Analysis. JEIT, 2018, 40(7): 1561-1566.
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