相位测频法在雷达脉冲载频提取中的应用

Application of Phase Frequency Measuring Method in Radar Pulse Carrier Frequency Measuring

脉内载频特征是雷达被动信号分选的关键参数,为提高雷达信号载频特征提取精度,引入相位测频法。利用希尔伯特变换将原始信号转换为复信号,进而求取各采样点对应的相位及瞬时频率,对各点瞬时频率取均值作为信号载频特征。将相位测频法与傅里叶变换法、计数法进行了仿真对比,结果表明:相位测频法在低载频、短脉宽的情况下测频精确度优于傅里叶变换法和计数法。因此相位测频法应用于雷达载频特征提取,能有效提高测频精度和稳定性,为复杂背景下雷达被动信号分选与识别提供支持与保障。

Pulse carrier frequency measuring is very important in the radar passive signal sorting, in order to improve the accuracy of the radar signal carrier frequency feature extraction, the phase frequency measuring method is introduced in this paper. The original signal is converted into complex signal by using the Hilbert transform, and the phase and instantaneous frequency corresponding to each sampling point are obtained. The mean frequency of each point is taken as the signal carrier frequency characteristic. The phase frequency measuring method is compared with the Fourier transform method and the counting method. The results show that the accuracy of the phase frequency measuring method is better than the Fourier transform method and the counting method in the case of low carrier frequency and short pulse width. Therefore, the phase frequency measuring method which is applied to the radar carrier frequency feature extraction, can effectively improve the accuracy and stability of frequency measurement. It provides support and guarantee for radar passive signal sorting and identification in complex background.