正弦调频傅里叶变换的自旋微动群目标分辨

Resolution of Group Targets with Spinning Micro-Motion Based on Sinusoidal Frequency Modulation Fourier Transform

近年来针对孤立目标的微动特征提取技术已较为成熟,但针对群目标的分辨与微动特征提取技术尚有待深入研究。以空间自旋微动群目标为例,提出了一种基于正弦调频傅里叶变换的自旋微动群目标分辨方法。建立了自旋微动群目标的回波模型,在此基础上采用正弦调频傅里叶变换来提取回波中的微多普勒特征分量。针对正弦调频傅里叶变换在分析多分量正弦调频信号时所特有的交叉项问题,提出了一种有效的交叉项抑制方法。结合交叉项抑制方法,利用正弦调频傅里叶变换处理自旋群目标微动信号,实现了对自旋微动群目标的分辨,并准确地提取出各子目标自旋频率特征。

The technique of extracting isolated target micro-motion feature has already been comparative mature in recent years, but the technique of extracting group targets micro-motion feature remains to be further studied. Taking space autorotation micro-motion as example, a resolution scheme of group targets based on sinusoidal frequency modulation Fourier transform （SFMFT） is proposed in this paper. First, an echo model of group targets with spinning micro-motion is established, and SFMFT is applied in extracting micro-Doppler component on the basis of the above- mentioned. Then, a suppression method of cross-term in SFMFT is put forward in view of the problem that the sinusoidal frequency modulation Fourier trans- form （SFMFT） displays the characteristic cross-term in analyzing multi-component sinusoidal frequency modulation signals. Finally, combined with the proposed cross-term suppression method, group targets with spinning micro-motion are effectively resolved tion signals of the sinusoidal frequency modulation sub-target is accurately extracted. by utilizing the group targets with spinning micro-mo- Fourier transform, and the spinning frequency of each