GPS/BDS/Galileo precise orbit determination using triple-frequency uncombined observation model
ZENG Tian, SUI Lifen, RUAN Rengui, JIA Xiaolin, XIAO Guorui
Acta Geodaetica et Cartographica Sinica . 2021, (2): 169 -180 .  DOI: 10.11947/j.AGCS.2021.20200159