基于斜距高阶近似的弧形阵列SAR成像方法

Imaging Approach for Arc Array SAR Based on High-Order Approximation of Slant Range

弧形阵列合成孔径雷达(Synthetic Aperture Radar, SAR)是一种新型的针对广域观测的阵列成像雷达,其具有观测范围广,分辨率高等特点。由于其回波信号方位向等角度间隔采样,目标精确的二维频谱难以有效推导,并且已有的线性阵列成像算法不再适用。针对上述问题,本文提出了一种基于斜距高阶近似的弧形阵列SAR成像处理方法,该方法首先对斜距模型进行高阶近似,然后推导了雷达回波信号的二维频谱,之后在二维频域补偿距离徙动及距离方位的耦合,最终得到聚焦图像。点阵目标的仿真结果验证了该成像方法的有效性。

Arc array synthetic aperture radar(SAR)is a novel array imaging system for wide-area observation.It has a wide range of observations and high resolution.Due to the characteristics of azimuth sampling at equal angular intervals,it is difficult to derive the two-dimension spectrum of the target echo signal,and existing imaging algorithms of linear array are no longer applicable.As for above issues,a new arc array SAR imaging processing method based on high-order approximation of slant range is presented.The method performs high-order approximation for the range model,obtains the two-dimensional spectrum of the target echo signal through series reversion,and then compensates the range migration and the coupling of distance and azimuth in the two-dimensional frequency domain.Finally,obtains the focused image.Simulation analysis of the point targets validates the effectiveness of the imaging approach.