毫米波干涉仪信号处理研究

【作者】 陶金泉；

【导师】 许建中；

【作者基本信息】 南京理工大学 ， 信号与信息处理， 2009， 硕士

【摘要】 弹丸内弹道速度测量对武器系统的研制有着重要的指导意义,毫米波干涉仪利用多普勒效应,获取运动目标的瞬时频率,能够对弹丸膛内速度实现精确的测量。传统的信号分析方法-傅立叶变换只能在时域或频域对信号进行分析,缺乏时频域联合分析的手段,无法对瞬时频率进行精确的计算分析。时频分析方法是近年来信号处理研究的一个热点,为非平稳信号的分析提供了有力工具。这种分析方法提供了信号时间域与频率域的联合分布信息,因此可以清楚的描述信号频率随时间变化的关系。介绍了时频分析理论的基本知识,给出了几种主要的时频分析方法:短时傅立叶变换,Wigner-Ville变换,连续小波变换以及希尔伯特黄变换,就各种时频分析方法在信号处理中的应用作了较深入的研究。最后给出毫米波干涉仪测试系统的组成结构,基于希尔伯特黄变换和短时傅立叶变换,对毫米波干涉仪采集的实际信号进行了时频分析,实现了对弹丸内弹道速度的精确测量。更多还原

【Abstract】 The measurement of the velocity of projectile in interior ballistics has an important guiding significance on the development of weapon system. The millimeter-wave interferometer can get the instantaneous frequency of moving target in use of doppler effect, and measure the velocity of projectile precisely.Traditional signal analysis method-Fourier transform can only analyze the signal in time domain or frequency domain. Fourier transform lacks of the method of conjoint analysis from both time domain and frequency domain, can not compute instantaneous frequency of signal precisely.Time-frequency analysis is a hot spot in area of signal processing in recent year. It is a powerful tool for analyzing non-stationary signal. This method provides conjoint distribution information in both time domain and frequency domain, so it can describe the relationship between time and frequency.The paper introduces the knowledge of time-frequency analysis. Some detailed methods are introduced, such as Short Time Fourier Transform(STFT), Wigner-Ville Distribution(WVD),Wavelet Transform(WT) and Hilbert-Huang Transform(HHT). These methods are deeply researched on the application of signal processing.In the end, the millimeter-wave interferometer’s composition structure is introduced. The actual signal acquired by interferometer is analyzed in use of time-frequency analysis based on STFT and HHT. The precise measurement of the velocity of projectile in interior ballistics is realized.更多还原