一种星座遮挡场景下的GNSS接收机选星策略

A GNSS Receiver Satellite Selection Strategy in Constellation Occlusion Scenario

GNSS接收机在城市、密林和峡谷等环境下工作时,卫星信号受遮挡严重,造成星座残缺情况。针对北斗卫星导航定位系统中传统的最大四面体体积法不能有效反映遮挡情况的问题,提出了一种基于几何精度因子(Geometric Dilution Precision,GDOP)值分析的新型选星策略。设置高度角阈值,在满足阈值条件下结合卫星高度角、方位角,分析几何布局,通过构造最大四面体体积选出参与定位解算的卫星组合。经计算机仿真验证分析得出,在星座遮挡场景下该算法相较于最佳GDOP算法计算量减少了95%以上,相比最大四面体体积法性能提升了2.62 dB,在保证定位精度的同时实现了准确快速的选星,具有良好的性能和可行性。

When GNSS receivers work in environments such as cities,dense forests and canyons,the constellation may be incomplete since satellite signals are seriously blocked.Considering that the traditional maximum tetrahedron volume method cannot reflect the occlusion effectively in Beidou satellite navigation and positioning system,a new satellite selection strategy based on Geometric Dilution Precision(GDOP)analysis is proposed.The altitude angle threshold is set,and the geometric layout is analyzed according to the altitude angle and azimuth angle of the satellite when the threshold condition is met,and the satellite combination participating in the positioning solution is selected by constructing the maximum tetrahedral volume.The computer simulation results show that in constellation occlusion scenario,the calculation amount of the algorithm is reduced by more than 95%compared with the optimal geometric accuracy factor algorithm,and the performance is improved by 2.62 dB compared with the maximum tetrahedron volume method.The algorithm can achieve accurate and fast satellite selection while ensuring the positioning accuracy,and it has good performance and feasibility.