基于线阵的MIMO-ISAR二维成像方法

针对多输入多输出逆合成孔径雷达(MIMO-ISAR)成像中空-时阵列非均匀造成的成像数据不均匀，该文基于线阵建立了目标空-时回波信号模型，经过推导，提出一种相同距离单元横向聚焦的成像方法。该方法首先进行距离补偿，将空时分布的距离像对齐至目标初始位置；然后构建相位因子，补偿非关心方向运动引起的相位变化；最后对相同距离单元数据沿横向相干叠加，实现横向聚焦。该算法不受阵列形式的限制，无需数据均匀化处理，而且能够横向定标，仿真验证了该方法的有效性。

Two-dimensional Imaging Using MIMO Radar and ISAR Technique Based on Linear Array

In view of the uneven imaging data caused by the uneven space-time array in the MIMO-ISAR imaging, the echo signal model of a target is established based on a linear array, an imaging algorithm that focuses on the cross-range direction following range unit is proposed. The range compensation is applied firstly, which can make range profiles that distribute in the space-time domain align at the initial position of target. Then phase changes caused by motion in unconcerned direction are compensated. Finally, the range profiles are focused in the cross-range direction following range unit by coherent addition. The algorithm is not restricted by the structure of the array and the processing of uniformity is not needed. In addition, it can determine the ISAR image scale in the cross-range direction. The simulation results verify the validity of the proposed algorithm.