通过对多输入多输出合成孔径雷达(MIMO-SAR)的虚拟空间采样进行等效观测通道重构,可实现宽测绘带内的多通道合成孔径成像与地面运动目标显示(SAR/GMTI)处理。在建立宽测绘带MIMO-SAR运动目标观测模型的基础上,分析了该模式下MIMO-SAR运动目标回波与传统SAR系统运动目标回波的区别。并利用成对回波原理建立了目标回波的等效微动模型,提出了空间通道重构模式下MIMO-SAR运动目标的等效微动效应,并讨论了运动目标回波的时频谱线数目。最后,数值仿真验证了文中结论的正确性。
The SAR/GMTI in wide-swath can be obtained by reconstructing virtual space samplings of MIMO-SAR into equivalent observation channels. Based on the properties of the configuration of wide-swath MIMO-SAR, the echo signal of moving target was firstly studied to reveal the distinctness with the echo signal of traditional SAR system. The effect of the echo signal of moving target in MIMO-SAR was also studied using paired echo principle (PEP). This analysis decomposed the echo signal into equivalent micro-motion phenomenon, which had a similar characteristic with micromotion target. Then, the expected time-frequency spectrum of MIMO-SAR in wide-swath was discussed in detail. Finally, numerical simulations give the validity of conclusions.