滑窗模式下大斜视SAR波数域性质分析及成像算法研究

Property Analysis and Imaging Algorithm Research in Wavenumber Domain of High Squint SAR in Sliding Window Mode

摘要:

为解决滑窗模式下大斜视聚束合成孔径雷达(synthetic aperture radar, SAR)的精确、高效成像问题,对SAR波数域性质及成像算法进行了研究。首先建立了滑窗模式下的时域回波信号模型,并基于固定窗模式下的回波二维频谱,对传统距离徙动算法(range migration algorithm, RMA)进行改进, 提出了一种基于滑窗接收的波数域拓展算法;然后对滑窗模式下信号波数域频谱特征及采样点映射关系进行分析,提出了雷达视线坐标系下二维空间域解耦方法,并给出了对应的成像处理流程;最后通过仿真实验和实测数据处理实验验证了算法的有效性。

Abstract:

In order to solve the problem of accurate and efficient imaging of high squint focused synthetic aperture radar (SAR) in sliding window mode, the wavenumber domain properties and imaging algorithms of SAR were studied. First, time domain echo signal model in sliding window mode was established. On the basis of 2-D echo spectrum in fixed window mode, the traditional range migration algorithm (RMA) was improved, and a wave number domain expansion algorithm based on sliding window reception was proposed.Then, the spectrum characteristics of wavenumber domain and the mapping relationship of sampling points in sliding window mode were analyzed, and the 2-D spatial domain decoupling method in radar line-of-sight coordinate system was proposed, and the corresponding imaging processing flow was given. Finally, the validity of the algorithm was verified by simulation experiment and actual data processing experiment.