GNSS天线相位中心模型更新对PPP的影响分析

Analysis of differences between GNSS antenna phase center correction models and their effects on precise point positioning

目前,天线相位中心改正(PCC)模型由igs14.atx更新至igs20.atx,更新后的PCC模型会对精密单点定位的坐标参数估计产生影响。本文对比了更新前后的PCC模型,综合分析了四大全球卫星导航系统(GNSS)的在轨卫星和接收机天线的PCC模型,并选取了31个国际全球卫星导航系统服务组织(IGS)测站的观测数据进行精密单点定位数,通过点位偏差和点位精度来分析模型间差异对测站点位估计的影响。结果表明:在IGS框架和天线产品更新后,全球定位系统(GPS)、格洛纳斯系统和伽利略系统的点位偏差下降0.7、2.4和1 mm,北斗三号全球卫星导航系统(BDS-3)增加了0.3 mm;4个系统的点位精度与更新前相当,变化在1 mm内。多GNSS系统联合处理下定位效果有明显改善,点位偏差平均减少了约1.2 mm,点位精度提高了1.5 mm。除此之外,在IGS20框架下使用igs14.atx中的模型后,4个系统的定位性能受到不同程度的影响。

Antenna phase centre correction(PCC)model updated from igs14.atx to igs20.atx.Changes arising from the updated PCC model affected the estimation of coordinate parameters for precise point positioning(PPP).This paper compared the PCC models,and comprehensively analysed the PCC models of the in-orbit satellites and receiver antennas of the four major global navigation satellite systems(GNSS).Observations from 31 International GNSS Service(IGS)stations were selected for PPP data processing to analyse the effect of inter-model differences on station point estimates through point deviation and point accuracy.The results showed that after the updating of the IGS frame and antenna products,the point deviations of global positioning system(GPS),global'naya navigatsionnaya sputnikovaya sistema(GLONASS)and Galileo satellite navigation system(Galileo)decreased by 0.7 mm,2.4mm and 1mm,and the BeiDou-3 global navigation satellite system(BDS-3)was comparable to that before the updating,with an increase of 0.3mm;and the positioning accuracies of the four systems were comparable to those before the updating,with a change within 1mm.There would be a significant improvement in the positioning effect under the joint processing of multiple GNSS systems,with an average reduction of about 1.2 mm in the point deviation and an improvement of 1.5 mm in the positioning accuracy.In addition,the positioning performance of the four systems could be affected to varying degrees by the use of the model in igs14.atx under the IGS20 frame.