Air-to-Ground (A2G) communication is considered as a significant enabler technology in next-generation networks. To make this a reality, a comprehensive understanding of the A2G channels is vital. This paper presents an Elevation Angle (EA) based two-ray mean path loss model for the A2G channels. In particular, we present closed-form expressions for the path loss with respect to the elevation angle and compare the results with ray-tracing simulation results. Our results show that mean path loss for the A2G channels can be accurately characterized by the proposed EA based two-ray model. Our study investigates different altitudes of the aerial terminal, different types of terrains, and two polarizations, wherein the proposed EA-based two-ray model matches well with the ray-tracing simulation results. Furthermore, a comparison of the proposed model with the other known path loss models in the literature is conducted. Finally, this work reveals an interesting relationship between the elevation angle and the signal down-fades, that these signal down-fades appear at approximately the same elevation angles regardless of the platform altitude.

空对地 (A2G) 通信被认为是下一代网络中的重要推动技术。要实现这一目标，全面了解 A2G 渠道至关重要。本文提出了一种基于仰角 (EA) 的 A2G 信道的两射线平均路径损耗模型。特别是，我们提出了相对于仰角的路径损耗的封闭形式表达式，并将结果与​​光线跟踪模拟结果进行了比较。我们的结果表明，A2G 信道的平均路径损耗可以通过所提出的基于 EA 的两射线模型来准确表征。我们的研究调查了天线终端的不同高度、不同类型的地形和两种极化，其中提出的基于 EA 的双射线模型与射线追踪模拟结果匹配良好。此外，将所提出的模型与文献中其他已知的路径损耗模型进行了比较。最后，这项工作揭示了仰角和信号衰落之间的有趣关系，无论平台高度如何，这些信号衰落都以大致相同的仰角出现。