Satellite precise orbit determination with ionospheric-free strategy using triple-frequency observations
ZENG Tian, SUI Lifen, RUAN Rengui, JIA Xiaolin, FENG Laiping
Acta Geodaetica et Cartographica Sinica . 2020, (10): 1275 -1284 .  DOI: 10.11947/j.AGCS.2020.20190325