【作者】 李岳霖；

【导师】 庞伟正；

【作者基本信息】 哈尔滨工程大学 ， 信号与信息处理， 2008， 博士

【摘要】 低信噪比信号检测和微弱回波信号处理是多谱勒体制测速雷达在雷达信号处理领域中所面临的主要问题,雷达的四大威胁之一便是来自于各种地、海杂波干扰。以非平稳信号处理理论为工具来研究和解决这一问题,是信号处理领域新的热点之一。论文紧密结合轻武器多谱勒体制弹道测速雷达信号处理的特点,以工程应用背景为要求,充分利用国家靶场现有测试设备及技术,积极吸收国内外先进的研究成果,将小波变换、高阶统计量、短时傅立叶变换等非平稳信号处理手段引入多谱勒测速雷达微弱回波信号处理中,从理论上分析解读了轻武器测速雷达测速工作原理及信号处理方法,研究探索了适合轻武器低伸弹道特点的微弱弹道信息处理理论及方法。本文研究的主要内容和创新点如下:1.提出一种利用四阶累计量作为抑制噪声,提取多谱勒速度的计算方法。该方法解决了传统的频谱分析处理精度差的问题,通过对四阶累积量进行简化递推,易于工程实现。2.提出一种基于小波包HMM去噪的方法,解决了低伸弹道信号信噪比低的检测难题。仿真实验表明,在强噪声背景下进行局部信号去噪,小波包变换优于小波变换。3.对雷达法进行了改进,提出基于小波分析和基于改进的短时傅立叶变换法提取弹丸转速的方法。对比国家靶场试验结果,得出基于改进的短时傅立叶变换的时频分析方法,更适合工程需要,能得到高精度的试验数据的结论,解决了轻武器弹丸转速测试问题。4.提出一种基于小波分析的弹丸曳光飞行时间抽取方法,国家靶场试验证明该方法可使雷达回波信号特征在不同分辨率下显露出来。根据信号幅度的变化,找到信号的突变点,测试精度满足指标要求,为国军标的修正提供依据。综上所述,论文对轻武器弹道测速雷达微弱回波信号进行了深入的研究,作者提出的处理方法,对国家靶场轻武器试验鉴定具有重要意义,具有很高的理论水平和应用推广价值。更多还原

【Abstract】 Signal detection of Low signal-to-noise ratio and extraction of weak echo signal are the main problems in the field of radar signal processing of Doppler velocity estimation radar system. One of the four threats for radar is the clutter interference from land and sea. And to research and solve the problem with the Non-steady signal processing theory is one of the arousing interests in the field of signal processing. Taking the engineering application background as request, taking the premise of fully utilizing national range existing test facility and technology and positively absorbing the advanced research findings both at home and abroad, introducing the Non-steady signal processing methods such as Wavelet Transform, High Order Statistics, Short-time Fourier transformation etc. into the process of Doppler velocity estimation radar weak echo signal, the paper analyzes the operational principle for velocity measurement and the signal processing techniques of small arms velocity estimation radar in detailed theory and explores weak ballistic information processing theories and methods that are suitable for low trajectory of small arms in close integration with the information processing features of small arms Doppler ballistic velocity estimation radar system. The main contents and new ideas are as follows:1. Put forward a method using fourth-order cumulants for noise reduction and the extraction of Doppler velocity which worked out the problem of bad precision by traditional frequency spectrum analysis method.Engineering realization becomes easier by simplified Recursive estimation of fourth-order cumulants.2. Bring up de-noising method based on wavelet HMM which worked out the problem of detection for low signal to noise ratio(SNR) on low stretched trajectory. Simulation experiment make it clear that wavelet package transform outgoes wavelet transform by using local signal de-noising method under the strong noise background.3. Improved on radar method and proposed a method for extraction of pill rotate speed based on wavelet analysis and improved short-time Fourier Transform method.Compared with the experimental result from nation shooting range it’s clear that time-frequency analysis method based on improved short-time Fourier Transform method fits engineering requirement more which can obtain high-precision datas.4. Propose a extraction technology of projectile tracer’s flight time based on wavelet analysis method.The test from nation shooting range proved that the method can make radar echo signal’s characteristics unveiled.According to signal amplitude’s variation signal’s break point was found and the test precision meet target requirement quite well which provides evidence for national’s military standard.To sum up, the paper makes deep research on small arms ballistic velocity estimation radar weak echo signal. The methods proposed by the author are of far reaching importance to the National range testing evaluation and is much worthy to be generalized and applied.更多还原