一种宽波束机载SAR运动误差的频域补偿方法

A Motion Compensation Algorithm in Frequency Domain for Wide-beam Airborne SAR

对于方位向宽波束机载SAR系统的运动补偿在实际应用中具有重要意义。该文提出了一种对宽波束机载SAR系统运动误差进行频域补偿的方法。利用线性调频信号的时频对应关系,将时域误差转换到频域,基于短时傅里叶变换进行逐块的频域误差校正,得到精确聚焦的图像。文中对算法原理、适用条件、算法流程和运算量进行了详细分析。对P波段机载SAR系统低频运动误差情况进行了点目标和图像的仿真,验证了该方法的有效性。

Motion Compensation is essential for wide-beam airborne Synthetic Aperture Radar （SAR）. This paper proposes a motion compensation algorithm for wide-beam airborne SAR based on phase correcting in frequency domain for azimuth blocks. With the relationship between time and frequency of chirp signal, residual errors in time domain are mapped into frequency domain and compensated. Short Fourier Transforms are used to gain high efficiency. This paper analyzes the principle, limitations, processing steps and efficiency of the algorithm. Simulation of point target and images of a P band airborne SAR with low-frequency motion errors validates the proposed algorithm.