旋翼类目标调制谱间隔特征分析与条件研究

Analysis and research on modulation spectral interval characteristics and extraction conditions for rotor-type targets

为了对旋翼类目标谱间隔特征进行有效提取,基于旋翼类目标回波模型,对旋翼类目标喷气发动机调制(JEM)特征中包含的调制谱间隔特征进行了分析,并对谱间隔提取条件进行了探究.首先从理论上分析旋翼类目标回波中调制谱间隔特征产生的机理,分析影响谱间隔大小的因素;再讨论有效提取谱间隔特征需要满足的条件,最后通过仿真验证了理论分析结论的可靠性.研究结果表明:旋翼类目标调制谱间隔只取决于桨叶数量和转速,采样时间需满足一定条件才能有效提取谱间隔特征,这个条件仅与桨叶数量和转速有关.

In order to extract the spectral interval features of rotor-type target effectively,this paper is based on the rotor-type target echo model to analyze the modulation spectral interval feature contained in the jet engine modulation(JEM)features of rotor-type target,also exploring the extraction conditions of the spectrum interval.Firstly,the mechanism of modulation spectral interval feature generation in rotor-type target echoes is analyzed theoretically,and the factors affecting the magnitude of spectral interval are also analyzed.Then,the conditions needed for extracting spectral interval feature effectively are discussed.Finally,simulation analysis is carried out,verifying the reliability of the theoretical analysis.The results show that the modulation spectral interval of rotor-type targets depends only on the number and the rotational speed of blades,and that the spectral interval features can be extracted effectively only when the sampling time meets a certain condition,which is only related to the number and the rotational speed of blades.