基于时间反转和降阶Keystone的SAR-GMTI快速聚焦方法

对合成孔径雷达（SAR）地面运动目标聚焦技术进行了研究。针对现有运动目标聚焦方法存在的问题，提出了一种基于时间反转和降阶Keystone的SAR地面运动目标检测（SAR-GMTI）快速聚焦方法。首先，根据目标的机动特性建立了3阶距离模型；其次，针对目标多普勒中心模糊引起的多普勒谱分裂现象，结合所提时间反转处理（TRP）和降阶Keystone变换处理估计出运动目标2阶参数。此后，构造2阶相位补偿函数补偿运动目标的2阶距离徙动和多普勒徙动，从而完成运动目标的聚焦。同时，所提方法没有任何参数搜索过程，降低了计算复杂度。最后，仿真实验验证了所提算法的正确性和有效性。

A fast SAR-GMTI focusing method based on time reversal and reduced-order Keystone

This paper describes the ground moving target focusing technique for the Synthetic Aperture Radar (SAR). For the problems existing in the present methods for ground moving target focusing, a fast SAR Ground Moving Target Indication (SAR-GMTI) focusing method based on time reversal and reduced-order Keystone processing is proposed. A three-order range model is established according to the characteristics of the maneuvering target. To eliminate the effects of Doppler spectrum split caused by doppler center blur, the proposed Time Reversal Processing (TRP) and reduced-order Keystone transform processing are combined to estimate the target second-order motion parameter. The second-order phase compensation function is constructed to compensate the second-order range migration and Doppler migration, and a focused result of a moving target is obtained. The proposed method has low computational complexity without any searching procedure. Simulations are provided to verify the validity of the proposed method.