高功率微波在电离层中传播的折射率研究

Refractive index of HPM at transionospheric propagation

高功率微波在电离层中的传播特性主要由其折射率的变化决定,而高功率微波的大气折射率与相应传输层面的电子浓度有关。结合电离层电子浓度分布模型对电子浓度和大气折射率进行了数值模拟,对电离层折射率以及折射率垂直梯度相对于高度的变化特性进行了分析。结合射线描迹法对高功率微波波束传播高度、仰角和距离进行了修正,并在低功率微波下进行实验验证,证实修正值更接近实际值。

The characteristic of high power microwave（HPM） propagation through ionosphere is mainly determined by the diversification of the atmospheric refractive index, while the refractive index has positive correlation with the electron concentration at corresponding propagation layer. The critical frequency of ionosphere in linearity condition and the atmospheric refractive index formula are derived. The electron concentration and the atmospheric refractive index are numerically simulated based on ionospheric electron concentration distributing model. The diversification of the refractive index and the refractive index gradient relating to the altitude are also analyzed, and experiment has been taken under low power microwave condition which validates that the corrected value is closer to the practicality than the value operated from general theory. Hence the altitude, elevation and incept power of HPM propagation can be modified by the theory of this paper, which can also provide theoretic reference to practical HPM propagation.