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 

作者机构：School of Geodesy and GeomaticsWuhan University129 Luoyu RoadWuhan430079China Hubei Luojia Laboratory129 Luoyu RoadWuhan430079China German Research Centre for Geosciences GFZTelegrafenberg14473PotsdamGermany Technische Universitat Berlin(TUB)Straße Des 17.Juni10623BerlinGermany 

出 版 物：《Satellite Navigation》 (卫星导航（英文）)

年 卷 期：2024年第5卷第1期

页      面：125-139页

核心收录：

学科分类：08[工学] 081601[工学-大地测量学与测量工程] 0816[工学-测绘科学与技术] 

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) 

主　　题：Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center 

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)*** 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 *** 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 ***,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 *** from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%*** 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)*** assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is uti