摘要
方位多通道SAR系统通过抑制多普勒模糊,能够实现高分辨率和宽测绘带(HRWS)对地观测。针对通道间幅相偏差会导致成像结果中出现目标模糊分量的问题,该文提出一种通道相位偏差估计算法。该算法利用通道间相位偏差会造成多通道重构方位谱在主瓣内展宽的特性,通过优化多谱勒谱能够实现通道相位偏差的有效估计。该算法在通道相位偏差估计前不需要进行多普勒中心估计,减小了由多普勒中心估计不准引入的误差,并且在低信噪比的情况下仍然具有良好的估计性能。基于仿真数据和实测数据的实验验证了该文算法的有效性。
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.
作者
王志斌
刘艳阳
李真芳
陈筠力
WANG Zhibin LIU Yanyang LI Zhenfang CHEN Junli(National Laboratory of Radar Signal Processing, Xidian University, Xi＇an 710071, China Shanghai Institute of Satellite Engineering, Shanghai 201109, China Shanghai Academy of Space Technology, Shanghai 201109, China)
出处
《电子与信息学报》
EI
CSCD
北大核心
2016年第12期3026-3033,共8页
Journal of Electronics & Information Technology
基金
国家自然科学基金(61471276
61601298
61671355)~~
关键词
合成孔径雷达
高分辨率宽测绘带
多通道
数字波束形成
通道相位偏差估计
多普勒谱优化
Synthetic Aperture Radar （SAR）
High-Resolution and Wide-Swath （HRWS）
Multi-channel
DigitalBeam-Forming （DBF）
Phase bias estimation
Doppler spectrum optimization
