利用KWT进行动目标成像的三通道SAR-GMTI快速目标运动参数估计

该文提出一种基于Keystone-Wigner变换进行运动目标成像的快速目标参数估计方法。快速目标的径向速度会引起距离走动和方位多普勒偏移，仅根据干涉相位值无法获取准确的动目标多普勒中心，而辅以走动率信息则可以解多普勒中心模糊以得到正确的径向速度估计。动目标沿航向速度会引起方位调频率的改变，导致在常规SAR图像中动目标方位散焦，校正动目标距离走动后提取目标信号进行KWT分析，得到动目标调频率值，此时再取干涉相位求得径向速度，最后得到沿航向速度。该文在Dechirp域进行动目标检测，在提取快速目标径向速度过程中同时考虑了脉冲重复频率(PRF)模糊和干涉相位模糊，并最终实现了快速目标的准确定位和测速。实测数据处理结果验证了所提出方法的有效性。

Tri-channel SAR-GMTI High-Speed Target Imaging and Motion Parameter Estimation Using KWT

A parameter estimation method by imaging with the Keystone-Wigner Transform (KWT) for fast moving target is proposed. The radial velocity of fast moving target can cause the range walk and azimuth Doppler shift, so the accurate Doppler center can not be obtained only with interferometric phase, but with the range walk ratio of the target the Doppler ambiguity can then be resolved and the accurate Doppler center can be acquired. The along-track velocity of the fast moving target will result in the changing of the Doppler rate, and makes the moving target defocused in conventional SAR image. The Doppler rate can be attained with KWT after the range walk is removed, then the radial velocity can be obtained with the interferometric phase and following the along-track velocity of the target can be attained. The moving target indication is processed in the Dechirped domain, and in the case of acquiring the along-track velocity of the target both the PRF ambiguity and the phase ambiguity are taken into account, so the relocation and the velocity estimation of the fast moving target can be achieved. The processing result of measured data illustrates the effectiveness of the method.