MIMO下视阵列SAR阵列抖动误差补偿算法

Array Vibrating Error Compensation Algorithm of MIMO Downward-Looking Array SAR

根据机翼抖振理论,将飞机机翼以机身为对称轴一分为二。每个虚拟阵元看作一个质点,构建了简易的阵列抖动误差模型,提出了MIMO下视阵列SAR系统阵列抖动误差补偿方法。该方法将阵列抖动误差分解为不依赖距离和依赖距离两部分。结合高效的三维距离多普勒成像算法,在距离压缩前执行不依赖距离的一次抖动补偿;在距离徙动校正和方位压缩之间执行依赖距离的二次抖动补偿和方位向时域插值重采样,从而实现观测场景的三维成像。以真实SRTM DEM为原始场景进行仿真实验,补偿前后的成像结果验证了方法的有效性。

According to the wing chattering theory,the aircraft wing was divided into two symmetrical parts. Each virtual element was considered as a particle,and a simple array vibrating error model was constructed. Then the array vibrating error compensation method of MIMO downward-looking array SAR system was proposed in this paper.The array vibrating error was decomposed into two parts,which included distance-independent one and distancedependent one. Combined with the efficient three-dimensional（ 3 D） RD imaging algorithm,distance-independent vibrating error was compensated before range compression,and distance-dependent vibrating error was compensated and azimuthal interpolation resampling in time domain was carried out between distance migration correction and azimuth compression to achieve 3 D imaging of observation scene. Simulation experiments were carried out with the real SRTM DEM as the original scene,and the effectiveness of the proposed method was verified by comparing the imaging results before and after compensation.