论文标题
近场SAR中的恒定时间延迟干扰：图像域中的分析和抑制
Constant-Time-Delay Interferences In Near-Field SAR: Analysis And Suppression In Image Domain
论文作者
论文摘要
SAR系统存在不可避免的干扰，对成像质量产生不利影响。但是，当前的分析和抑制方法主要集中于远场状况。由于干扰的不同来源和特征，它们不适用于近场。为了弥合这一差距，在这项工作中提出了第一次分析和近场SAR的干扰方法。我们发现，来自Nadir点和天线耦合的回声是主要的原因，它们具有恒定的时期特征。为了表征这一点，我们进一步建立了一个分析模型。它揭示了它们在1D，2D和3D成像结果中的模式都类似梳状，而目标的模式类似于点。利用这些功能，基于低级别的重建提出了图像域中的抑制方法。测得的数据用于验证我们的分析的正确性和抑制方法的有效性。
Inevitable interferences exist for the SAR system, adversely affecting the imaging quality. However, current analysis and suppression methods mainly focus on the far-field situation. Due to different sources and characteristics of interferences, they are not applicable in the near field. To bridge this gap, in the first time, analysis and the suppression method of interferences in near-field SAR are presented in this work. We find that echoes from both the nadir points and the antenna coupling are the main causes, which have the constant-time-delay feature. To characterize this, we further establish an analytical model. It reveals that their patterns in 1D, 2D and 3D imaging results are all comb-like, while those of targets are point-like. Utilizing these features, a suppression method in image domain is proposed based on low-rank reconstruction. Measured data are used to validate the correctness of our analysis and the effectiveness of the suppression method.
