高原地区VHF地空通信覆盖范围影响因素研究

Research on Factors Affecting Coverage of VHF Ground-to-Air Communication in Highland Areas

针对利用地形遮蔽法计算的民航VHF通信信号覆盖范围较粗略的问题,提出了一种在原有的算法下加入雾衰减从而提高信号覆盖精度的算法模型,并构建可视化的显示平台。首先,以西藏某高原地区VHF通信监视台站为例,利用地理信息系统从实际的地图中获取台站周围的数字高程模型(DEM),计算在地形影响下不同高度层上的信号传播截止距离;其次,根据国际电联无线电通信部门(ITU-R)P系列建议书中的雾衰减模型,构造在地形和雾共同影响下的新算法模型;最后,给定飞行高度、发射频率、发射功率等进行仿真。结果表明,多因素影响下的信号覆盖范围比单因素下的覆盖范围精确,可以为VHF地面通信监视台站选址、飞行航线规划以及西部地区民航发展提供有效支撑。

To address the problem that the coverage of civil aviation VHF communication signals calculated by u⁃sing terrain masking method is coarse,an algorithm model is proposed to add fog attenuation under the original algo⁃rithm so as to improve the signal coverage accuracy and build a visual display platform.Firstly,taking a VHF commu⁃nication monitoring station in a plateau area of Tibet as an example,the digital elevation model(DEM)around the station was obtained from the actual map using GIS to calculate the signal propagation cutoff distance at different alti⁃tude levels under the influence of terrain;Secondly,based on the fog attenuation model in the P series recommenda⁃tion of the International Telecommunication Union(ITU-R),a new algorithm model was constructed under the com⁃bined influence of terrain and fog model;Finally,simulation experiments were conducted given the flight altitude,transmitting frequency,and transmitting power.The results show that the signal coverage under the influence of multi⁃ple factors is more accurate than that under single factor,which can provide effective support for the site selection of VHF ground communication monitoring stations,flight route planning and civil aviation development in western region.