地形遮挡对GNSS干扰范围影响的高效仿真算法

在卫星导航对抗效能的仿真中,真实地理环境的地形遮挡对全球导航卫星系统(global navigtion satellite system, GNSS)干扰源干扰范围影响的仿真计算是个重要问题。通常情况下,地形遮挡对GNSS干扰范围影响的计算通过基于视线可视域分析的算法得到,但该方法存在大量冗余计算。为了减少计算量,提出一种基于参考面可视域分析的GNSS干扰范围高效仿真计算方法,利用干扰源与目标点附近可视高程值对应的辅助格网点建立参考面,通过目标点实际高程值与参考面映射高程值判断目标点的受干扰情况,避免了目标点与干扰源视线方向上多个采样点的插值计算。仿真分析表明,当待分析区域半径约为145 290 m时,该算法与传统基于视线可视域分析的GNSS干扰范围仿真计算方法相比, Matlab耗时大幅减少了97.38%,但结果差异并不明显，仅为0.94%。因此,所提方法可以高效、准确地计算出地形影响下GNSS干扰范围,为干扰源优化部署、战场环境仿真分析等提供理论指导。

Efficient simulation algorithm for the influence of terrain occlusion on the GNSS interference range

In the simulation of satellite navigation countermeasure effectiveness, the simulation calculation for the influence of terrain occlusion on the interference range of the global navigation satellite system (GNSS) interference source in real geographical environment is an important problem. In general, the calculation of the influence of terrain occlusion on GNSS interference range is obtained by the algorithm based on the line-of-sight viewshed analysis, but there are a lot of redundant calculations in this method. In order to reduce the amount of calculation, an efficient simulation calculation method of GNSS interference range based on the viewshed analysis of reference surface is proposed. The reference surface is established by using the auxiliary grid point corresponding to the visual elevation value near the interference source and target point. The interference situation of the target point is judged by the mapping elevation value of the target point and the actual elevation value of the reference surface, which avoides the interpolation calculation of multiple sampling points in the line-of-sight direction between the target point and the interference source. Simulation analysis shows that when the radius of the area to be analyzed is about 145 290 m, compared with the traditional simulation method of GNSS interference range based on the line-of-sight viewshed analysis, the Matlab time consumption is greatly reduced by 97.38%, but the results difference is not obvious, only 0.94%. Therefore, the proposed method can efficiently and accurately calculate the GNSS interference range under the influence of terrain, and provide theoretical guidance for the optimal deployment of interference sources and battlefield environment simulation analysis.