Phase Bias Estimation Algorithm for HRWS SAR System in Azimuth Based on Doppler Spectrum Optimization
WANG Zhibin① LIU Yanyang② 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)
By suppressing the Doppler ambiguity, the along-track multi-channel Synthetic Aperture Radar (SAR) system can simultaneously achieve High-Resolution and Wide-Swath (HRWS) imaging. However, the presence of unavoidable amplitude and phase bias tends to the absence of ambiguous signals in the SAR images. To address this issue, a novel phase bias estimation algorithm based on Doppler spectrum optimization is proposed. By exploiting the fact that phase bias can cause Doppler spectrum broadened, the phase bias can be successfully estimated by optimizing the Doppler spectrum. The Doppler centroid estimation can be avoided before phase biases estimation, which reduces the estimation accuracy caused by the inaccurate Doppler centroid. The proposed algorithm can achieve better performance when Signal to Noise Ratio (SNR) is low. The effectiveness of the algorithm is validated by experimental results carried out on simulated data and SAR data collected by an air- borne multi-channel system.
王志斌,刘艳阳,李真芳,陈筠力. 基于多普勒谱优化的HRWS SAR系统通道相位偏差估计算法[J]. 电子与信息学报, 2016, 38(12): 3026-3033.
WANG Zhibin, LIU Yanyang, LI Zhenfang, CHEN Junli. Phase Bias Estimation Algorithm for HRWS SAR System in Azimuth Based on Doppler Spectrum Optimization. JEIT, 2016, 38(12): 3026-3033.
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