机载多通道雷达地面微动目标检测方法

发布时间：2018-01-27 03:04

本文关键词： 微多普勒鬼影点干涉相位空域导向矢量改善因子　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：目前,有关合成孔径雷达地面运动目标检测技术的研究主要集中于匀速或匀加速等平动的运动目标,且一般采用二阶近似距离模型对其进行重聚焦成像。而实际上,地面运动目标存在如摆动,振动,旋转等周期性的微动形式,此时传统的距离近似模型不能准确描述微动目标的斜距历程。本文首先建立了多通道合成孔径雷达体制下海面摆动散射点及地面振动、旋转散射点的微动目标几何模型,比较了传统多项式展开理论与成对回波理论在目标斜距展开时的适用范围和应用条件。得出若目标存在周期性的微动,则利用成对回波理论对其斜距进行展开比利用多项式展开更加准确。其次,介绍了前人在双通道合成孔径雷达体制下对地面振动目标回波在数据域中进行检测及杂波抑制的处理方法,分析了该类方法的局限性和不准确性。借助鬼影点成对回波理论与SAR-RD算法,推导出了微动目标回波在图像域内的矢量表达式,分析了微动对单通道方位散焦的影响并推导出了地面振动目标的通道间干涉相位。建立回波鬼影点的归一化幅度及鬼影点空域导向矢量与杂波空域导向矢量间相关系数这两个性能指标,仿真验证了在较强杂波环境中,利用鬼影点对地面运动目标进行检测仍具有良好的改善因子性能。
[Abstract]:At present, the research of synthetic Aperture Radar (SAR) ground moving target detection is mainly focused on the translational target with uniform velocity or uniform acceleration. And the second-order approximate distance model is generally used to refocus the image, but in fact, there are periodic fretting forms such as swing, vibration, rotation and so on. At this point, the traditional distance approximation model can not accurately describe the oblique distance history of fretting target. In this paper, firstly, the scattering points of sea surface swing and ground vibration under multi-channel synthetic aperture radar (SAR) system are established. In this paper, the geometric model of the micro-moving target with rotating scattering points is presented. The application of the traditional polynomial expansion theory and the pairwise echo theory to the oblique distance expansion of the target is compared, and the periodic fretting of the target is obtained. Then using the pairwise echo theory to expand the oblique distance is more accurate than the polynomial expansion. Secondly. This paper introduces the methods of detecting and suppressing clutter of ground vibration target in data domain under the dual channel synthetic aperture radar (SAR) system. The limitations and inaccuracies of this method are analyzed, and the vector expression of fretting target echo in image domain is derived with the help of ghost point pair echo theory and SAR-RD algorithm. The influence of fretting on single channel azimuth defocusing is analyzed and the interchannel interference phase of ground vibration target is deduced. The normalized amplitude of echo ghost point and the phase between spatial guidance vector and clutter guidance vector are established. The relationship number is two performance indexes. Simulation results show that in a strong clutter environment, the detection of ground moving targets by ghost points still has a good performance of improvement factor.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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