| 摘要: |
| 高超声速目标在临近空间飞行时，目标周围及尾迹区域中电离形成的等离子体对卫星信号的传播会造成较大的衰减，这一现象有助于针对高超声速目标的被动式雷达探测。为研究全球卫星导航系统（Global Navigation Satellite System, GNSS）信号在鞘套尾迹中的衰减特性，采用计算流体动力学模拟了高超声速目标在不同飞行条件下的三维绕流流场，并以此建立绕流流场电磁模型。然后通过改进的移位算子时域有限差分方法（Shift Operator Finite?Difference Time?Domain, SO?FDTD）仿真计算GNSS信号在目标流场尾迹中的衰减特性，并绘制了信号通过流场后的透射系数分布图。仿真计算发现，临近空间高超声速目标尾迹对GNSS信号有明显的衰减作用，GNSS信号载波频率、目标飞行的高度和速度对GNSS信号透射系数的大小及分布结构均会带来影响。该研究中的结论为基于GNSS的临近空间高超声速目标无源探测提供了一定依据。 |
| 关键词: 高超声速 等离子体鞘套 移位算子时域有限差分方法 信号透射系数 无源探测 |
| DOI：DOI:10.3969/j.issn.1672-2337.2023.01.005 |
| 分类号:TN958 |
| 基金项目: |
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| Study on Attenuation Characteristics of GNSS Signal in Hypersonic Target Wake |
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FENG Shijie
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Research Institute of Electronic Science and Technology, University of Electronic Science and Technology of China, Chengdu 611731, China
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| Abstract: |
| When a hypersonic target flies in the near space, the satellite signal will be greatly attenuated by the ionized plasma around the target and in the wake region. This phenomenon is helpful for passive radar detection of hypersonic targets. To study the attenuation characteristics of global navigation satellite system （GNSS） signal in sheath wake, the flow field around hypersonic target under different flight conditions is simulated by the computational fluid dynamics, and the electromagnetic model of the flow field around hypersonic target is established. Then, the attenuation characteristics of GNSS signal in the wake of the target flow field are simulated by the improved shift operator finite?difference time?domain （SO?FDTD） method, and the transmission coefficient distribution diagram of the signal passing through the flow field is drawn. Simulation results show that GNSS signal is obviously attenuated by the wake of hypersonic target in near space. The number of transmission coefficient and distribution structure of transmission coefficient are affected by signal carrier frequency, target flight height and speed. Conclusions from this paper can be provided as basis for passive detection of hypersonic targets in near space based on GNSS. |
| Key words: hypersonic speed plasma sheath SO⁃FDTD signal transmission coefficient passive detection |
