摘要
当再入物体以高超声速飞行时,其表面被等离子鞘套覆盖。等离子鞘套对雷达回波产生幅度、相位和频率调制,严重影响了雷达对再入目标的可靠探测能力,导致多种雷达探测异常问题。通过建立等离子鞘套包覆目标的雷达回波模型,分析了等离子鞘套对雷达回波产生的影响。提出了一种基于慢时间自相关的多普勒频率对消方法,可以有效的解决非均匀等离子鞘套所引起的雷达回波中脉内多-多普勒频率现象,并运用扩展Keystone变换及变尺度逆傅里叶变换对相关后信号中的耦合项进行解耦,进而实现信号的能量聚焦。通过对多周期回波信号进行仿真分析,验证了本文所提算法的有效性,并结合统计实验分析验证了算法的可靠性,该算法可以通过对等离子鞘套包覆目标进行能量聚焦来完成运动参数的估计。
As the reentry object travels at hypersonic speeds,its surface is covered by a plasma sheath.The plasma sheath modulates the radar echo in amplitude,phase and frequency,which seriously affects the reliable detection capability of the radar for re-entry targets and results in various abnormal radar detection problems.In this paper,the influence of the plasma sheath on the radar echo is analyzed by establishing a radar echo model for the target covered by the plasma sheath.A Doppler frequency cancellation method based on slow time autocorrelation is proposed,which can effectively solve the multi-Doppler frequency phenomenon in the radar echo caused by the non-uniform plasma sheath.The extended Keystone transform and the inverse Fourier transform are used to decouple the coupling terms in the correlated signal,thereby realizing energy focusing of the signal.The validity of the algorithm proposed is verified by the simulation analysis of the multi-period echo signal,and the reliability of the algorithm is verified by statistical experimental analysis.This study provides an effective method for the coherent accumulation of the plasma sheath covered target.
作者
张廷焜
李铮
温旭东
洪逸清
白博文
ZHANG Tingkun;LI Zheng;WEN Xudong;HONG Yiqing;BAI Bowen(School of Aerospace Science and Technology,Xidian University,Xi’an 710126,China;Beijing Institute of Adjacent Space Vehicle Systems Engineering,Beijing 100076,China;Unit 63601 of the PLA,Korla 841000,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第S02期70-78,共9页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(62171349,62001388,61627901)
陕西省自然科学基础研究计划(2020JM-102)
关键词
等离子鞘套
雷达回波
脉冲内多普勒频率
慢时间自相关
相参积累
plasma sheath
radar echo
intra-pulse Doppler frequency
slow time autocorrelation
coherent accumulation
