基于变迹滤波的MIMO-SAR图像分辨率增强技术

针对多输入多输出合成孔径雷达(MIMO-SAR)在近场目标散射特征诊断成像中,非正交旁瓣难以通过常规方法进行有效抑制的问题,分析了MIMO-SAR图像非正交旁瓣的产生机理,提出了基于空间变迹滤波(SVA)和三变迹处理相结合的旁瓣抑制方法。仿真和实验结果表明,本文方法不仅能很好地抑制距离向旁瓣,而且对于方位向非正交旁瓣也具有较好的抑制效果,提高了MIMO-SAR图像的二维分辨率和动态范围。

Enhanced resolution in MIMO-SAR imaging using apodization

When the conventional methods of sidelobe suppression are used in multiple input multiple output synthetic aperture radar (MIMO-SAR) systems to generate images for diagnosing the near field scattering features of targets,non-orthogonal sidelobes can hardly be suppressed efficiently.In this paper,based on the generation mechanisms of the non-orthogonal sidelobes in near filed,an approach which combines spatially variant apodization (SVA) with tri-apodization was proposed to suppress the non-orthogonal sidelobes for MIMO-SAR images.Simulation and experimental results demonstrate that the sidelobes in down range as well as the non-orthogonal sidelobes in cross range are suppressed efficiently via the proposed approach.As a consequence,for MIMO-SAR images,the resolutions in both the down range and the cross range are improved remarkably while a higher dynamic range can be achieved.