Orbit and clock products for quad-system satellites with undifferenced ambiguity fixing approach  

作　　者：Jiaqi Wu Xingxing Li Yongqiang Yuan Keke Zhang Xin Li Jiaqing Lou Yun Xiong 

机构地区：[1]School of Geodesy and Geomatics,Wuhan University,129 Luoyu Road,Wuhan,430079,China [2]Hubei Luojia Laboratory,129 Luoyu Road,Wuhan,430079,China [3]German Research Centre for Geosciences GFZ,Telegrafenberg,14473,Potsdam,Germany [4]Technische Universitat Berlin(TUB),Straße Des 17.Juni,10623,Berlin,Germany

出　　处：《Satellite Navigation》2024年第1期125-139,共15页卫星导航（英文）

基　　金：supported by the National Natural Science Foundation of China(No.42204017,No.41974027,No.42304019);the special fund of Hubei Luojia Laboratory(220100006);the Sino-German mobility program(Grant No.M-0054),China Postdoctoral Science Foundation(2023M732687);the Fundamental Research Funds for the Central Universities(2042022kf1001).

摘　　要：Integer Ambiguity Resolution(IAR)can significantly improve the accuracy of GNSS Precise Orbit Determination(POD).Traditionally,the IAR in POD is achieved at the Double Differenced(DD)level.In this contribution,we develop an Un-Differenced(UD)IAR method for Global Positioning System(GPS)+BeiDou Navigation Satellite System(BDS)+Galileo navigation satellite system(Galileo)+Global'naya Navigatsionnaya Sputnikovaya Sistema(GLONASS)quad-system POD by calibrating UD ambiguities in the raw carrier phase and generating the so-called carrier range.Based on this method,we generate the UD ambiguity-fixed orbit and clock products for the Wuhan Innovation Application Center(IAC)of the International GNSS Monitoring and Assessment System(iGMAS).One-year observations in 2020 from 150 stations are employed to investigate performance of orbit and clock products.Notably,the UD Ambiguity Resolution(AR)yields more resolved integer ambiguities than the traditional DD AR,scaling up to 9%,attributable to its avoidance of station baseline formation.Benefiting from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%improvement.Compared with the float solution,the orbit consistencies of UD AR solution achieve the accuracy of 1.9,5.2,2.8,2.1,and 2.7 cm for GPS,BeiDou-2 Navigation Satellite System(BDS-2),BeiDou-3 Navigation Satellite System(BDS-3),Galileo,and GLONASS satellites respectively,reflecting enhancements of 40%,24%,54%,34%,and 42%.Moreover,the standard deviations of Satellite Laser Ranging(SLR)residuals are spanning 2.5–3.5 cm,underscoring a comparable accuracy to the DD AR solution,with discrepancies below 5%.A notable advantage of UD AR lies in its capability to produce the Integer Recovered Clock(IRC),facilitating Precise Point Positioning(PPP)AR without requiring additional Uncalibrated Phase Delay(UPD)products.To assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is utilized.In comparison to the float solution,the

关 键 词：Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center 

分 类 号：P22[天文地球—大地测量学与测量工程]