一种微波光子雷达ISAR成像新方法

微波光子雷达发射信号带宽大、波长短，能够实现分辨率更高的逆合成孔径雷达(ISAR)成像。但带宽大、波长小的回波信号也导致传统成像算法对目标转动分量的近似不成立，使得传统算法无法应用。在微波光子雷达成像中，目标转动分量在回波包络中形成空变的距离弯曲项，在方位相位中形成空变的2次相位误差，导致ISAR图像散焦。该文针对微波光子雷达系统提出一种新的ISAR成像算法，该算法同时考虑了目标转动分量对回波包络和相位的影响，以包络相关值为目标函数值迭代估计目标转速，根据转速估计值，在距离向进行重采样对齐包络，在方位向构造空变的方位补偿函数校正转动相位。仿真和实测数据的处理结果证明了该算法的有效性。

A Novel ISAR Imaging Algorithm for Microwave Photonics Radar

Microwave photonics radar generates signals with large bandwidth and small wavelength. It has capability of ultra-high resolution of Inverse Synthetic Aperture Radar(ISAR) image. Because the approximation of rotational components is not tenable, traditional ISAR imaging algorithm is not suitable to microwave photonics radar. In the microwave photonics radar imaging, the rotational components result in range curvature and quadratic phase error changing with distance. To solve this problem, an effective ISAR imaging algorithm is put forward which considers the influence of the target’s rotational component to echo envelope and phase. The value of envelope correlation is take as objective function and the target’s rotate speed is estimated by iteration; The range curvature is corrected by time resampling; The quadratic phase error is compensated by azimuth compensation function. Both simulated and real-measured data experimental results confirm the effectiveness of the proposed algorithm.