W波段UAV MISAR实时成像运动补偿方法

建立了实时成像正侧视合成孔径雷达(SAR)运动误差模型,采用了一种基于惯导和相位梯度自聚焦(PGA)运动误差估计的中心波束平面运动补偿算法。该算法对回波包络和相位进行分开补偿,利用惯导数据把带有运动误差的回波包络拉直,再利用相位梯度自聚焦算法对回波进行相位误差估计并补偿。针对实时成像的时间少、运算量大、运算资源受限等特点,该算法取消了距离徙动校正的步骤,将运动误差矢量在斜距平面投影并完成包络校正和相位误差估计。该方法运算量小,同时能满足分辨率要求。仿真结果表明:该方法能够得到质量较高的SAR图像。

The Motion Compensation Method for W-Band UAV MISAR Real-Time Imaging

A motion error model for real-time imaging forward-looking synthetic aperture radar (SAR) is established, and a center beam motion compensation algorithm based on inertial navigation and phase gradient autofocus (PGA) motion error estimation is adopted. In the algorithm, the echo envelope and the phase are compensated separately, the inertial navigation data are used to straighten the echo envelope with the motion error, and then the PGA algorithm is used to estimate and compensate the phase error of the echo. In view of the characteristics of real-time imaging such as short time, a large amount of computation, and limited computing resources, in the algorithm, the step of range migration correction is canceled, the motion error vector is projected on the slant plane, and the envelope correction and phase error estimation are completed. The method has a small amount of calculation, and can meet the resolution requirement. The simulation results show that the method can obtain high quality SAR images.