This paper investigates a novel ground moving target indication (GMTI) scheme for a hypersonic vehicle-borne multichannel synthetic aperture radar (MC-SAR) system with Doppler ambiguity. First, after the range compression and azimuth chirp Fourier transform (CFT), by applying the eigenspace-based adaptive sum and difference beams (EASDB) on the coarse-focused images, the high-precision cross-track velocity (CTV) can be retrieved. Then, utilizing the high-precision CTV to construct an accurate moving target steering vector to extract the moving target energy. With the proposed CFT-two-step method, we have avoided cumbersome CTV search, and simplified the process of range walk correction, resulting in lower computational complexity. Compared to the CFT-center and CFT-two-step methods, the proposed scheme obtains the accurate two-dimension motion parameters of a moving target, and has better performance and robustness in the detection, focusing, and location, preserving the moving target envelope and achieving higher signal-to-clutter-and-noise ratio (SCNR). Finally, using the processing results of simulation and real measured MC-SAR data, we verify the effectiveness and feasibility of our proposed scheme.

本文研究了一种用于具有多普勒模糊度的高超声速车载多通道合成孔径雷达 (MC-SAR) 系统的新型地面移动目标指示 (GMTI) 方案。首先，经过距离压缩和方位线性调频傅里叶变换（CFT）后，通过对粗聚焦图像应用基于特征空间的自适应和差波束（EASDB），可以反演高精度的横轨速度（CTV） . 然后，利用高精度CTV构造精确的运动目标导向向量，提取运动目标能量。使用所提出的 CFT-两步法，我们避免了繁琐的 CTV 搜索，并简化了距离步行校正的过程，从而降低了计算复杂度。与 CFT 中心法和 CFT 两步法相比，提出的方案获得了运动目标的准确二维运动参数，在检测、聚焦和定位方面具有更好的性能和鲁棒性，保留了运动目标的包络，实现了更高的信噪比（ SCNR）。最后，利用仿真处理结果和实测MC-SAR数据，验证了所提方案的有效性和可行性。