超宽带(Ultra-Wide Band, UWB)雷达通常具有距离高分辨能力,从而在目标识别及成像等方面有着广阔的应用前景。然而,该雷达中径向速度不变的目标的多普勒频率随 UWB 信号频率变化而变化,即所谓的多普勒色散现象更加凸显,若将常规窄带雷达的信号处理方法应用于 UWB 雷达通常导致相关性能下降。此外,对于存在径向运动的目标,如多载频及线性调频(Linear Frequency Modulation, LFM)的调制信号存在的距离-多普勒耦合导致目标距离像移动及扩展,从而使得UWB雷达距离高分辨能力受到影响。 本文围绕 UWB雷达目标距离及速度展开相关的研究,主要工作包括:超宽带雷达运动目标多普勒色散特征表示,要求有理论表达式;超宽带雷达多普勒色散对雷达信号处理性能的影响;多普勒色散补偿和聚焦方法。 9894
关键词:UWB雷达,回波模型,多普勒色散,多普勒色散积,距离-多普勒耦合,匹配滤波,色散补偿
Title Ultra-Wide Band (UWB) radar Doppler dispersion
analysis and compensation method
Abstract
Ultra-Wide Band (UWB) radar possesses a very broad application prospect
in the fields of target identification and imaging, etc., since the radar
usually has outstanding performance of range resolution. However, the
Doppler frequency of UWB radar target with constant radial velocity varies
with the frequencies of UWB signal, i.e. Doppler dispersion phenomenon.
This phenomenon becomes more prominent than narrow band radar, and makes
it difficult to estimate velocity of moving target for UWB radar by using
the conventional signal processing methods suitable for narrow radar.
Besides, for moving target with radial velocity, the modulation UWB
signals, such as multi-carrier frequency and linear frequency modulation
(LFM), etc., have range-Doppler coupling, which causes that the range
profile moves and spreads seriously along range dimension. It is found that
the capability of high range resolution of UWB radar is greatly restricted.
This thesis focuses on target detection of range and velocity profiles for
UWB radar, including: Ultra-Wide Band radar target motion doppler
dispersion characteristics, requiring a theoretical expression;
Ultra-Wide Band Radar doppler dispersion has what influence on the
performance of the radar signal processing; Doppler dispersion
compensation and focused methods.
Keywords UWB radar, echo model, Doppler dispersion, Doppler dispersion
product, range-doppler coupling, matched filtering, dispersion
compensation
目 次
1 绪论 1
1.1 研究背景及意义 1
1.2 研究动态和发展现状 2
1.3 论文的主要工作及组织结构 5
2 UWB雷达多普勒色散特征 7
2.1 引言 7
2.2 UWB雷达回波模型 7
2.3 多普勒色散特征. 13
2.4 本章小结. 20
3 LFM UWB 雷达目标距离估计及速度补偿 . 21
3.1 引言. 21
3.2 二文 FFT处理. 21
3.3 距离-多普勒耦合 26
3.4 速度补偿. 27
3.5 本章小结. 29
结论. 30
致 谢. 31
参考文献. 32 1 绪论
1.1 研究背景及意义
德国物理学家 Heinrich Hertz 于1885~1888 年间,通过实验首次验证了英国
物理学家James Clerk Maxwell 于1864年提出的电磁场理论,并发现无线电波可
被金属物体反射。这为雷达(Radio Detection and Ranging, Radar)的发展奠定了理
论基础。自 20 世纪初,特别是第二次世界大战以来,雷达引起美、德、苏、英 超宽带雷达信号多普勒色散分析和补偿方法研究:http://www.youerw.com/tongxin/lunwen_8775.html