MIMO-ISAR匀加速旋转目标运动参数估计及性能分析

Motion Parameter Estimation and Performance Analysis for Constant Accelerating Rotating Target in MIMO-ISAR Imaging

MIMO雷达采用ISAR技术成像时需要估计目标的运动参数,为回波数据的方位向重排与插值提供依据,以及实现距离-多普勒图像的横向定标。针对匀加速旋转目标,该文提出一种初始角速度和转动加速度联合估计方法。借助MIMO雷达多通道观测的结构优势,根据不同通道回波间相位差异,通过估计差异信号相位系数获得目标运动状态。在此基础上,分析了算法推导过程中因函数近似引起的误差,同时对算法的分辨能力给出定量评估。最后,通过仿真验证了分析推导的正确性。

Rotational motion estimation is essential for MIMO radar imaging with ISAR technique. According to the estimation, the echo data can be rearranged and interpolated, and the cross-range scaling can be implemented for range-Doppler imaging. For an object rotating with a constant acceleration, a method is proposed to jointly estimate the initial rotating velocity and the rotating acceleration. It estimates the phase factors of the difference signal by exploiting the phase difference between the echo signals from two different channels of MIMO radar. Based on this, the errors induced by trigonometric approximation in the derivation of the method are analyzed, and then the influencing factors causing these errors are obtained. Meanwhile, the motion parameter estimation resolutions are assessed quantitatively. Finally, simulations are performed to verify the correctness of the proposed method and the analysis.