基于距离徙动轨迹的空间目标ISAR联合运动补偿算法

ISAR Joint Motion Compensation Algorithm Based on Range Migration Trajectory for Space Target

针对空间高速运动目标的运动特征,分析目标距离徙动轨迹(Range migration trajectory,RMT)与等效运动模型,提出了一种基于距离徙动轨迹的联合运动补偿算法。该算法依据距离像全局熵值最小化原则,从RMT中估计出目标的平动参数,根据平动参数分别补偿距离像偏移并校正一维距离像畸变,从而实现对空间目标回波的距离对齐和脉内走动的联合平动补偿。仿真和实测数据处理结果表明该算法准确性较高,更重要的是,距离对齐步骤不会引入随机偏移误差和相位误差,这也是应用高分辨成像方法的前提条件。

Aiming at the motion features of high speed moving target in space,by analyzing the range migration trajectory(RMT)and the equivalent motion model of the target,a RMT-based joint motion compensation algorithm is proposed in this paper.In the algorithm,the translational parameters of the target are estimated from RMT according to the global entropy minimization principle.Then the range profile offset is compensated and one dimensional range alignment distortion is corrected by using these translational parameters,which can realize the joint motion compensation of range alignment and intra pulse moving for the space target echo.Simulational and experimental results show that the proposed algorithm has high accuracy.What’s more,ransom offset error and phase error cannot be introduced in the range alignment procedure,which is the precondition of high-resolution imaging method application.