多频Galileo精密单点定位瞬时模糊度固定性能评估

Performance Evaluation of the Multi-frequency Galileo Precise Point Positioning with Instantaneous Ambiguity Resolution

随着Galileo卫星系统的全面建成,多频Galileo观测值提供了更低噪声和更长波长的观测值组合,从而为Galileo瞬时精密单点定位(precise point positioning,PPP)模糊度固定(ambiguity resolution,AR)提供良好的条件。从三频无电离层组合观测模型出发,重点分析了Galileo各个频点观测值组合的噪声放大因子,并基于15个MGEX(multi-GNSS experiment)测站10天的观测数据评估了不同频率组合的Galileo瞬时PPP-AR定位精度。结果表明:在位置精度衰减因子(position dilution of precision,PDOP)较差时(PDOP=2.3),采用Galileo E1/E5a/E6频率的瞬时PPP-AR在东、北和天方向的均方根(root mean square,RMS)分别为0.16m、0.19m和0.45m,与GalileoE1/E5a/E5b瞬时PPP-AR定位解相比,在3个方向分别提高了约40%、38%和32%。以上结果表明,采用GalileoE1/E5a/E6组合对瞬时PPP-AR的定位精度有较大提升,因此当用户的全球导航卫星系统(global navigation satellite system,GNSS)接收机能接收到Galileo E1/E5a/E6频点时,建议采用这三组频点进行定位。

With the full completion of the Galileo satellite system,the combination of observations with lower noise and longer wavelengths can be provided by multi-frequency Galileo observations.Therefore,it is possible to achieve Galileo instantaneous precision point positioning(PPP)with ambiguity resolution(AR).Based on the triple-frequency iono-sphere-free combination observation model,we analyze the noise amplification factors of Galileo observations with different frequencies.Experimenting on the observation data from 15 multi-GNSS experiment(MGEX)stations in 10 days,the positioning performance of Galileo instantaneous PPP-AR is assessed with different frequency combination.When the position dilution of precision(PDOP)is weak(PDOP=2.3),the results indicate that the root mean square(RMS)of Galileo E1/E5a/E6 for east,north and up components are 0.16 m,0.19 m and 0.45 m,respectively.Compared with the solutions of Galileo E1/E5a/E5b,the Galileo E1/E5a/E6 shows an improvement of approximately 40%,38%and 32%for east,north and up components,respectively.Therefore,the Galileo E1/E5a/E6 can bring a significant improvement in the instantaneous PPP-AR,and we suggest that these three signals should be used for positioning if the Galileo E1/E5a/E6 can be tracked by the user's global navigation satellite system(GNSS)receiver.