基于稀疏表示理论的微弱核辐射信号检测方法研究及实现

发布时间：2018-03-24 19:16

本文选题：稀疏表示　切入点：核脉冲信号重构　出处：《西南科技大学》2017年硕士论文

【摘要】：随着核科学技术的飞速发展,其应用领域越来越广泛,给我们的生活带来巨大利益的同时,一旦发生核泄漏、核恐怖袭击以及核材料丢失等事故,将对社会公共安全造成极大的威胁。因此,加强对核辐射信号的探测,及时遏制核事故的发生,具有十分重要的现实意义。目前,基于伽马能谱的传统核信号探测方法,由于受环境本底噪声的影响,很难实现对微弱核信号的探测。因此,研究高效率的微弱核信号探测方法,具有十分重要的工程应用价值。本文从信号表征出发,结合理论与实际工程应用,重点研究基于稀疏表示的微弱核脉冲信号重构与分解方法以及实验实现。具体研究内容如下:针对强非平稳时变噪声背景下微弱核辐射信号信噪比低的问题,通过改进的匹配追踪算法和正则匹配追踪算法,分析核辐射信号在时域、频域上的特征,对传统核辐射信号探测方法进行研究,进而提出基于稀疏表示理论来恢复核辐射信号的方法。通过稀疏表示理论中的分解算法和重建算法,建立信噪分离模型,依据核脉冲信号特征建立具有自适应特征的Gabor冗余字典,基于该字典并利用正则匹配追踪算法对核脉冲信号进行恢复。设计核辐射探测实验平台,基于该平台验证了匹配追踪算法和正则匹配追踪算法在实现微弱核脉冲信号恢复的有效性。
[Abstract]:With the rapid development of nuclear science and technology, its application is becoming more and more extensive, which brings great benefits to our life. At the same time, once there are nuclear leakage, nuclear terrorist attacks and loss of nuclear materials and other accidents, Therefore, it is of great practical significance to strengthen the detection of nuclear radiation signals and to contain the occurrence of nuclear accidents in time. At present, the traditional nuclear signal detection method based on gamma spectroscopy is of great practical significance. It is very difficult to detect weak nuclear signal because of the influence of background noise. Therefore, it is very important to study the detection method of weak nuclear signal with high efficiency. Combining theoretical and practical engineering applications, The reconstruction and decomposition method of weak nuclear pulse signal based on sparse representation and its experimental implementation are studied. The main contents are as follows: aiming at the problem of low signal-to-noise ratio of weak nuclear radiation signal under strong non-stationary time-varying noise background, Through the improved matching tracing algorithm and the regular matching tracking algorithm, the characteristics of nuclear radiation signal in time and frequency domain are analyzed, and the traditional nuclear radiation signal detection method is studied. Then, a method based on sparse representation theory to recover nuclear radiation signal is proposed, and the separation model of signal and noise is established through the decomposition algorithm and reconstruction algorithm in sparse representation theory. Based on the feature of nuclear pulse signal, the Gabor redundancy dictionary with adaptive characteristics is established, and the nuclear pulse signal is recovered by using regular matching tracking algorithm. The experimental platform for nuclear radiation detection is designed. Based on this platform, the effectiveness of matching tracking algorithm and regular matching tracking algorithm in the restoration of weak nuclear pulse signal is verified.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TL751

【相似文献】