单脉冲频率步进雷达ISAR成像技术

发布时间：2019-02-27 08:02

【摘要】：频率步进雷达是一种重要的高分辨雷达,该体制雷达有效解决了距离分辨力与系统硬件要求以及瞬时带宽之间的矛盾,近些年来受到广泛关注。ISAR成像技术可以有效获取目标较为直观的二维图像和尺寸信息,大大降低了目标识别的难度,是目标识别的一项重要手段。将频率步进雷达应用于ISAR成像技术,二者的优势结合,一方面可以降低二维成像对系统瞬时带宽的要求,另一方面可以提高频率步进雷达的信息获取能力。本文详细梳理总结了单脉冲频率步进雷达ISAR成像的流程,并针对二者结合时产生的距离-多普勒耦合现象和横向定标方法进行了具体研究,提出了杂波背景下的成像目标筛选和基于单脉冲测角的横向定标算法。并分别使用仿真实验和实测数据对本文提出的成像流程和算法进行了验证。论文分为三个部分:第1部分主要介绍了频率步进信号和ISAR成像技术的相关知识和原理,重点介绍了频率步进雷达高分辨距离像的获取方法以及后文将重点使用的基于散射中心对齐的高分辨距离像抽取方法。第2部分针对频率步进信号应用于ISAR成像时产生的距离-多普勒耦合现象进行了具体研究,提出了利用频率步进信号的速度敏感性实现杂波背景多目标场景下成像目标的筛选,经过高分辨距离像抽取、平动补偿以及横向分辨得到感兴趣目标的高分辨二维像。并使用仿真实验和雷达外场实测数据对这一流程进行了验证。第3部分针对单脉冲频率步进雷达ISAR成像的横向定标方法进行了具体研究,提出了利用单脉冲测角技术测量目标运动轨迹进而对ISAR二维像横向定标的方法,进而基于单脉冲频率步进雷达的三通道高分辨距离像提出了基于高分辨距离像的测角方法。并使用仿真实验和雷达外场实测数据对这一横向定标方法进行了验证。
[Abstract]:Frequency stepping radar is an important high resolution radar, which effectively solves the contradiction between range resolution, hardware requirement and instantaneous bandwidth. In recent years, ISAR imaging technology can effectively obtain the two-dimensional image and size information of the target, which greatly reduces the difficulty of target recognition and is an important means of target recognition. The combination of the advantages of the frequency stepping radar and the ISAR imaging technology can reduce the requirement of the instantaneous bandwidth of the two-dimensional imaging system on the one hand, and improve the information acquisition ability of the frequency stepping radar on the other hand. In this paper, the ISAR imaging process of monopulse frequency stepping radar is summarized in detail, and the range-Doppler coupling phenomenon and lateral calibration method produced by the combination of them are studied in detail. The imaging target selection under clutter background and the lateral calibration algorithm based on monopulse angle measurement are proposed. Simulation experiments and measured data are used to verify the imaging flow and algorithm proposed in this paper. The thesis is divided into three parts: the first part mainly introduces the knowledge and principle of frequency stepping signal and ISAR imaging technology. This paper mainly introduces the method of obtaining high resolution range profile of frequency stepping radar and the high resolution range profile extraction method based on center alignment of scattering which will be used in the following paper. In the second part, the range-Doppler coupling phenomenon when frequency stepping signal is applied to ISAR imaging is studied in detail, and the velocity sensitivity of frequency stepping signal is used to screen the imaging target in clutter background multi-target scene. Through high resolution range profile extraction, translation compensation and lateral resolution, the high resolution two dimensional images of interested targets are obtained. Simulation experiments and radar field data are used to verify the flow. In the third part, the transverse calibration method for ISAR imaging of monopulse frequency stepping radar is studied in detail, and the method of measuring the moving trajectory of target by monopulse angle measurement technique and then the lateral calibration of ISAR two-dimensional image is put forward. Furthermore, an angle measurement method based on high resolution range profile is proposed based on the three-channel high resolution range profile of monopulse frequency stepping radar. The lateral calibration method is verified by simulation experiment and radar field measurement data.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52

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