弹道导弹的微多普勒特征参数提取方法研究

发布时间：2018-12-23 08:17

【摘要】：雷达作为远距离目标探测工具,可以实现对运动目标进行距离,角度以及运动速度的测量。随着雷达技术的不断完善,现代雷达已经扩展可以用于目标精细结构测量和精细运动特征提取等来进行目标的识别。但是由于近年来目标特征控制技术的飞速发展,使得假目标、诱饵等非合作目标已经能够较为精准进行模仿,从而使得基于传统特征进行的目标识别方法失去高效性。如何在军事防御中准确的识别出非合作目标已成为雷达领域目前的重要任务之一。运动物体会对雷达波的频率进行调制,从而导致回波的频率偏离发射频率,这种现象称为多普勒效应。如果除了物体质心的运动以外,其自身的结构部件还存在一些微小的运动(微动),将会在回波信号上引起额外的频率调制,形成与目标主体有关的多普勒边带,这种现象就是微多普勒效应。微多普勒特征是一个物体所具有的唯一不同于其他物体的特殊特征,而这些特征代表了物体的某些结构部件产生的精细频率调制,因此,借助于物体自身具有的这种特殊性进行其相应的提取,可以作为弹道导弹目标识别的新的思路和方法。本文首先简要介绍了课题的背景和意义,以及弹道导弹目标识别的发展状况,随后引入了关于雷达微多普勒效应及特征的一些理论知识,为论文的展开做铺垫。紧接着分别针对弹道导弹目标的不同微动形式(旋转、振动、进动)在窄带以及宽带雷达中进行模型建立以及分析。随后重点讨论了基于时频分析提取弹道导弹的微动特征参数的方法。从时频分析法的种类、弹头目标运动建模、雷达回波时频特性分析、基于时频分析法的微动特征参数提取方法及仿真等进行了较为详细的阐述。同时,着重针对微动特征参数随着散射点以及信噪比的变化特性进行相应的仿真和分析。最后,在简单概述现有的其它弹道导弹微动参数的提取方法的基础上,利用其中的倒谱法和延时共轭法与时频分析法进行了仿真对比,分析了三种方法的优劣,证明了时频分析法在弹道导弹目标识别中是相对比较稳健可靠的方法,可以较好地提取目标的微动特征参数。
[Abstract]:As a remote target detection tool, radar can measure the range, angle and velocity of moving target. With the continuous improvement of radar technology, modern radar has been extended to be used for target fine structure measurement and fine motion feature extraction for target recognition. However, due to the rapid development of target feature control technology in recent years, non-cooperative targets such as false targets, decoys and other non-cooperative targets can be imitated accurately, which makes the target recognition method based on traditional features lose its high efficiency. How to accurately identify non-cooperative targets in military defense has become one of the most important tasks in radar field. The frequency of radar wave is modulated by moving object, which causes the frequency of echo to deviate from the transmitting frequency. This phenomenon is called Doppler effect. If, in addition to the motion of the center of mass of an object, there are some small motions (fretting) in its own structural components, it will cause additional frequency modulation on the echo signal, forming a Doppler sideband associated with the target subject. This phenomenon is called the micro-Doppler effect. MicroDoppler features are the only unique features of an object that are different from other objects and represent fine frequency modulation generated by certain structural components of an object. It can be used as a new idea and method for ballistic missile target recognition with the help of the particularity of the object itself. In this paper, the background and significance of the subject and the development of ballistic missile target recognition are briefly introduced, and then some theoretical knowledge about radar micro-Doppler effect and its characteristics is introduced to pave the way for the development of the thesis. Then the models of different fretting forms (rotation, vibration, precession) of ballistic missile targets are established and analyzed in narrowband and wideband radar respectively. Then, the method of extracting fretting characteristic parameters of ballistic missile based on time frequency analysis is discussed. In this paper, the classification of time-frequency analysis method, the motion modeling of warhead target, the time-frequency characteristic analysis of radar echo, the method of extracting fretting characteristic parameters based on time-frequency analysis method and the simulation are described in detail. At the same time, the characteristic parameters of fretting are simulated and analyzed according to the variation of scattering point and signal-to-noise ratio (SNR). Finally, on the basis of a brief overview of the existing methods for extracting the fretting parameters of ballistic missiles, the cepstrum method and time-frequency method are used to simulate and compare them, and the advantages and disadvantages of the three methods are analyzed. It is proved that the time-frequency analysis method is relatively robust and reliable in ballistic missile target recognition, and it can extract the fretting characteristic parameters of the target.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：E927;TN95

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