基于频控阵的微波成像方法研究

Frequency diverse array (FDA) is a new array radar technique. By adding a small frequency to different transmitting array element, the beam pattern of FDA radar varies with the range information. Thus, due to the fact that an additional degree of freedom is introduced, FDA radar owns a lot of advantages in signal processing and attracts wide attentions around the world. Combining FDA technique with synthetic aperture radar (SAR), high resolution radar imaging will be achieved, making it helpful for target detection, tracking and identification. However, the characteristics of the FDA transmitting signal are different from that of the traditional phased array radar, the conventional phased array radar based SAR imaging algorithm will not hold water. Therefore, this project will investigate the FDA based microwave imaging method. Taking the optimization design theory into consideration, we will look for a new FDA radar imaging system beamforming method. This proposal will also aims at finding range and azimuth high resolution SAR imaging algorithm. The investigation results are of great value in providing technical support for the breakthroughs in radar imaging performance, and the development of high resolution radar imaging techniques.

频控阵雷达作为一种新体制阵列雷达技术，通过对不同发射阵元引入一个较小的频率增量，使其天线方向图的波束指向随距离变化而变化，进而在距离维增加了一个自由度，在信号处理性能上带来了诸多优势，近年来受到了国内外学者的广泛关注。结合频控阵和合成孔径雷达（SAR）成像技术，能够获得随距离空变的场景照射波束，进一步实现雷达高分辨观测成像，对目标的检测、跟踪和识别也有很大的帮助。然而，由于频控阵的发射信号特征不同于传统相控阵雷达，使得传统的基于相控阵的合成孔径雷达成像算法不再适用。因此，本项目着重研究基于频控阵的微波成像技术。结合最优化设计理论，探索频控阵的雷达成像系统发射波束形成新方法，研究基于频控阵的距离高分辨雷达成像处理方法以及方位高分辨聚束合成孔径雷达成像处理方法，提升雷达成像处理性能，为高分辨雷达成像关键技术的突破奠定理论基础。

频控阵因其发射阵元中的频率偏移增量，获得了距离维的额外自由度，成为了今年来关注度越来越高的新体制阵列技术。由于频控阵波束方向图的指向可随距离变化， 因此可对雷达信号处理技术产生积极的影响，尤其是合成孔径雷达成像。本项目将频控阵理论与合成孔径雷达技术有机的结合，拓展了应用场景，提高了系统性能，具体研究内容包括结合优化算法的雷达成像系统的频控阵发射波束形成设计方法，频控阵的距离高分辨成像方法和方位高分辨聚束合成孔径雷达成像方法展开，获得了积极的处理结果，研究成果相较于传统的相控阵雷达系统有着明显的性能提升，为今后新体制雷达探测与成像技术提供了重要的理论支持。