针对LPI信号分类识别问题中,时频图像受噪声干扰严重的问题,提出了一种基于二维快速经验模式分解(FBEMD)的图像降噪算法,并利用该算法实现对LPI信号的分类。首先利用时频分析方法,获得待分类信号的时频分布图像;使用二维EMD分解算法对...针对LPI信号分类识别问题中,时频图像受噪声干扰严重的问题,提出了一种基于二维快速经验模式分解(FBEMD)的图像降噪算法,并利用该算法实现对LPI信号的分类。首先利用时频分析方法,获得待分类信号的时频分布图像;使用二维EMD分解算法对图像降噪;截取包含时频信息的图像部分,通过主分量分析法提取特征矢量;最后采用RBF神经网络完成信号的分类识别任务。对常见的LPI雷达信号进行仿真,结果表明较低信噪比情况下,该方法仍能获得较好的分类结果。当信噪比为-2 d B时,采用二维EMD降噪算法,平均正确识别率能够达到93%。展开更多
随着电子对抗技术的不断发展,雷达的生存正经受着越来越严峻的威胁,为了雷达自身生存的需要,发展了低截获概率雷达。本文针对低截获概率雷达在雷达系统中的重要地位和作用,运用Laguerre变换等技术对典型的LPI(low probability of interc...随着电子对抗技术的不断发展,雷达的生存正经受着越来越严峻的威胁,为了雷达自身生存的需要,发展了低截获概率雷达。本文针对低截获概率雷达在雷达系统中的重要地位和作用,运用Laguerre变换等技术对典型的LPI(low probability of interception)雷达信号即线性调频信号和脉冲压缩信号进行分析,并在分析结论的基础上构建了LPI雷达信号检测系统,仿真结果表明,该检测系统能够对LPI雷达信号进行有效检测。展开更多
This paper mainly revolves the time-frequency image of low probability of intercept(LPI) radar signals and carries out research work on image features selection and extraction and recognition. Since Choi-Williams dist...This paper mainly revolves the time-frequency image of low probability of intercept(LPI) radar signals and carries out research work on image features selection and extraction and recognition. Since Choi-Williams distribution(CWD) uses the exponential kernel of bilinear generalized class of time-frequency distribution, it has an excellent time-frequency aggregation. And it is suitable for detecting LPI radar signals in a low signal-to-noise ratio(SNR) condition. A radial integration method based on the integral rotating factor is proposed to detect LPI radar signals when the signals' time-frequency image is obtained. First, the digital image processing method is used to preprocess the LPI radar signals' time-frequency images after CWD transformation; then, the radial integration method based on the integral rotating factor is used to detect LPI radar signals in the binary images. The analytic results of real data show that the method has a good performance on detecting LPI radar signals in a low SNR condition. Additionally,the method is simple and takes less logic resources and has the potential of real-time detection of LPI radar signals.展开更多
文摘针对LPI信号分类识别问题中,时频图像受噪声干扰严重的问题,提出了一种基于二维快速经验模式分解(FBEMD)的图像降噪算法,并利用该算法实现对LPI信号的分类。首先利用时频分析方法,获得待分类信号的时频分布图像;使用二维EMD分解算法对图像降噪;截取包含时频信息的图像部分,通过主分量分析法提取特征矢量;最后采用RBF神经网络完成信号的分类识别任务。对常见的LPI雷达信号进行仿真,结果表明较低信噪比情况下,该方法仍能获得较好的分类结果。当信噪比为-2 d B时,采用二维EMD降噪算法,平均正确识别率能够达到93%。
文摘随着电子对抗技术的不断发展,雷达的生存正经受着越来越严峻的威胁,为了雷达自身生存的需要,发展了低截获概率雷达。本文针对低截获概率雷达在雷达系统中的重要地位和作用,运用Laguerre变换等技术对典型的LPI(low probability of interception)雷达信号即线性调频信号和脉冲压缩信号进行分析,并在分析结论的基础上构建了LPI雷达信号检测系统,仿真结果表明,该检测系统能够对LPI雷达信号进行有效检测。
文摘This paper mainly revolves the time-frequency image of low probability of intercept(LPI) radar signals and carries out research work on image features selection and extraction and recognition. Since Choi-Williams distribution(CWD) uses the exponential kernel of bilinear generalized class of time-frequency distribution, it has an excellent time-frequency aggregation. And it is suitable for detecting LPI radar signals in a low signal-to-noise ratio(SNR) condition. A radial integration method based on the integral rotating factor is proposed to detect LPI radar signals when the signals' time-frequency image is obtained. First, the digital image processing method is used to preprocess the LPI radar signals' time-frequency images after CWD transformation; then, the radial integration method based on the integral rotating factor is used to detect LPI radar signals in the binary images. The analytic results of real data show that the method has a good performance on detecting LPI radar signals in a low SNR condition. Additionally,the method is simple and takes less logic resources and has the potential of real-time detection of LPI radar signals.
