Abstract
Triple-frequency GNSS has been intensively studying in the past decades, especially with the open service of China’s BeiDou system. In this review, we will address the ambiguity resolution, benefits gained from additional frequency signals compared to the dual-frequency GNSS signals, as well as analyse the challenges of triple-frequency GNSS for future development. We first review and compare the three carrier ambiguity resolution models of geometry-based, geometry-free, geometry-ionosphere-free (GIF). The benefits gained from triple-frequency GNSS are then comprehensively examined with respect to dual-frequency case, including the improved ambiguity resolution, extra-widelane based RTK, the augmented RTK service, the shortened PPP convergence, the improved availability and reliability. In addition, some challenges are discussed from both theoretical and practical aspects to open eyes for future research.
Highlights
As confirmed so far, there are at least three global Global navigation satellite systems (GNSS) systems which are broadcasting or will be upgraded to incorporate triple frequency signals, i.e., modernized GPS, Galileo and BeiDou systems
With the additional frequency signals, it is desirable to speed up the carrierphase ambiguity resolution (AR), mitigate the various categories of error sources, reduce the communication bandwidth of transmission and so on, improving both availability and reliability of the augmented Real time kinematic (RTK) applications (Herandez-Pajares et al 2003; Richert and El-Sheimy 2007; Feng and Li 2008, 2010)
Most of previous studies of making use of the additional frequency signals have concentrated on three carrier ambiguity resolution (TCAR), including the earlier contributions by Forssell et al (1997); Vollath et al (1998); Hatch et al (2000); Teunissen et al (2002); Feng and Rizos (2005); Fernández-Plazaola et al (2004) and Correspondence: bofeng_li@tongji.edu.cn College of Surveying and Geo-Informatics, Tongji University, Shanghai, People’s Republic of China the recent contributions by Cocard et al (2008); Feng (2008); Fernández-Plazaola et al (2008); Feng and Li (2010); Li et al (2010a); Henkel and Günther (2012); Geng and Bock (2013); Wang and Rothacher (2013); Li et al (2015b)
Summary
There are at least three global GNSS systems which are broadcasting or will be upgraded to incorporate triple frequency signals, i.e., modernized GPS, Galileo and BeiDou systems. Li et al (2015a) systematically studied the triple-frequency long-baseline RTK with EWL and NL observations where the partial NL AR is applied. To improve the model strength and meantime make use of ambiguity-fixed EWL observations, a new model is presented at last for NL AR.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
