混合构型低轨卫星增强GPS精密单点定位性能分析

Performance Analysis of GPS PPP Enhanced by Mixed Configuration LEO Satellites

低轨卫星具有信号强度高、运动速度快的特点,引入低轨卫星可改善矿区、城市、峡谷等复杂环境下GNSS接收机观测数据质量差、定位精度较低的问题。采用混合构型低轨星座进行定位增强,利用仿真低轨卫星数据对不同数量、不同构型的低轨卫星在不同截止高度角情况下增强GPS PPP性能进行分析。结果表明:(1)GPS联合LEO定位可以显著增加可见卫星数,降低PDOP值。(2)在截止高度角为30°时,低轨卫星可显著提高GPS定位性能,改善定位精度并减少收敛时间。其中,主子星座(96+9)联合GPS定位与同卫星数低轨卫星相比,在提升子星座覆盖区域测站(HKSL)N、U方向定位精度及减少收敛时间方面效果更好。

LEO satellites have the characteristics of high signal strength and fast movement speed.The introduction of LEO satellites can improve the poor quality of GNSS receiver observation data and low positioning accuracy in complex environments such as mining areas,cities,and canyons.In this paper,a mixed configuration LEO constellation is used for positioning enhancement,and the simulated LEO satellite data is used to analyze the performance of enhanced GPS PPP with different numbers and configurations under different cut-off elevation angles.The results show that:(1)GPS joint LEO positioning can significantly increase the number of visible satellites and reduce PDOP value.(2)When the cut-off elevation angle is 30°,LEO satellites can significantly improve GPS positioning performance,and improve positioning accuracy and reduce convergence time.Among them,GPS joint the main sub-constellation(96+9)can improve positioning accuracy and reduce convergence time of HKSL station in the sub-constellation coverage area in N and U directions compared with LEO satellites with the same number of satellites.