论文部分内容阅读
由于回波信号具有剧烈的二维耦合和距离徙动特性,相比传统的单站合成孔径雷达(SAR)而言,双站SAR数据的成像处理更具有挑战性,双站前视SAR则更是如此。由于没有解决距离徙动的空变性和高阶距离-方位耦合,导致目前现存的成像算法效果较差,成像范围也受到较大限制。针对上述问题,文中提出了一种基于二阶Keystone变换(KT)和改进的非线性调频变标(NLCS)方法的成像算法。首先,利用线性距离徙动矫正去除线性距离徙动和多普勒中心频率;然后,采用二阶KT来补偿距离弯曲;最后,采用改进的非线性调频变标方法用于均衡不同点目标方位空变的多普勒调频率。仿真结果证明了该算法的有效性。
Due to the dramatic two-dimensional coupling and distance migration characteristics of the echo signals, the imaging processing of the dual-station SAR data is more challenging than the traditional single-station SAR and the dual-station forward-looking SAR is more That’s it. Due to the lack of resolving the spatial degeneration of distance migration and the high-order distance-azimuth coupling, the existing imaging algorithms are ineffective and the imaging range is greatly limited. In view of the above problems, an imaging algorithm based on the second-order Keystone transform (KT) and the improved non-linear frequency modulation scaling (NLCS) method is proposed. First, the linear distance migration is used to remove the linear distance migration and the Doppler center frequency. Secondly, the second-order KT is used to compensate for the distance bending. Finally, an improved nonlinear frequency modulation method is used to balance the target azimuth Variable Doppler modulation frequency. Simulation results show the effectiveness of the algorithm.