基于DEM的民航地空VHF通信有效覆盖仿真研究

针对起伏地形环境下求解民航地空甚高频(very high frequency, VHF)通信有效覆盖范围冗余较大、精度较低的问题,采用改进的最大斜率法进行了仿真研究。首先,考虑遮蔽角计算存在计算冗余,提出"高程清洗"方法,降低计算量。其次,考虑求解最大斜率遮蔽角存在误差,采用改进的反距离加权插值法对原始数字高程模型数据进行插值提升分辨率,提高了切点逼近点位置精度。然后,为确定遮蔽区域具体点位,提出"切点截止法"进行求解。最后,为得到准确覆盖率,采用"网格法"分析计算。实验表明,改进的最大斜率法可有效减少计算冗余,提高信号覆盖求解精度,覆盖率相对改进前分别降低9.58%、4.10%和1.26‰。改进的VHF有效覆盖范围仿真程序可为VHF地面通信站选址、飞机航线规划提供支撑。

Simulation research on effective coverage of civil aviation ground to air VHF communication based on DEM

With respect to large redundancy and low accuracy of effective coverage of civil aviation ground-to-air very high frequency(VHF)communication in rugged terrains,the improved maximum slope method is applied for simulation research.Firstly,the“elevation mark”method is proposed to reduce the redundancy in the calculation of the shielding angle.Secondly,considering the calculating error in the maximum slope masking angle,the improved inverse distance weighted interpolation method is employed to interpolate the original digital elevation model data,enhancing the resolution and the position accuracy of the proximal point of tangent point.Then,the tangent-cut-off method is adopted to identify the specific points in the shelter area.Finally,the“grid method”is used to analyze the data for a more accurate coverage rate.The experimental results indicate that the improved maximum slope method can effectively reduce the calculation redundancy and increase the accuracy of the signal coverage,with the coverage rate reduced by 9.58%,4.10%and 1.26‰respectively in the three types of experimental terrains.The simulation program of the improved VHF effective coverage can significantly support VHF ground communication station location and aircraft route planning.