Multi-constellation GNSS precise point positioning with multi-frequency raw observations and dual-frequency observations of ionospheric-free linear combination

Xiangdong An,Weiping Jiang,Xiaolin Meng

doi:10.1186/s43020-020-0009-x

Xiangdong An, Weiping Jiang + Show 1 more

Open Access

https://doi.org/10.1186/s43020-020-0009-x

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Journal: Satellite Navigation	Publication Date: Feb 17, 2020
Citations: 37	License type: open-access

Affiliation: Wuhan University, University of Nottingham

Abstract

Precise point positioning (PPP) is famous for its capability of high-precision positioning with just one station as long as the receiver can receive global navigation satellite system (GNSS) signals. With the rapid development of BDS and Galileo, the number of available satellites for positioning has increased significantly. In addition, GPS III, GLONASS-K, BDS, and Galileo satellites can transmit triple-frequency signals. The potentials of multi-constellation GNSS PPP requires further analysis on a global scale. Therefore, we selected 96 multi-GNSS experiment (MGEX) stations with a global distribution and used 1 week’s data to assess the PPP performance. The results show that the PPP based on multi-frequency raw observations with spatial and temporal constraints has better performance than PPP using dual-frequency ionospheric-free observations. The main contribution of multi-constellation GNSS PPP is to shorten the convergence time. The convergence time for GPS PPP is approximately 40 min, which can be shortened to less than 20 min in multi-GNSS PPP. After convergence, the positioning accuracy of multi-GNSS PPP is improved by 0.5 to 1.0 cm compared with GPS or GLONASS PPP. The positioning accuracy of multi-GNSS could be further improved in the future with the BDS and Galileo precise products of orbits, clock and phase center offset/variation.

Highlights

Global navigation satellite system (GNSS) users mainly depended on American GPS or Russian GLONASS in the past
Satellite differential code bias (DCB) are corrected by the DCB products issued by Chinese Academy of Sciences [26], the receiver DCB are estimated as constants in one day Solved at each epoch by a white noise process GPS time as a reference and estimating GLONASS/BeiDou navigation satellite system (BDS)/Galileo to GPS inter-system bias for each station
Carrier‐phase and code residuals The post-fit code and carrier-phase residuals can help us to detect whether the Precise Point Positioning (PPP) model has other unmodeled errors

Summary

Introduction

Global navigation satellite system (GNSS) users mainly depended on American GPS or Russian GLONASS in the past. Rather than using observations of the IF combination, PPP based on raw observations is more convenient for multi-frequency GNSS data processing. Compared with the raw observation model, the observation equation based on IF linear combination is more simplified because it does not require the receiver DCB and ionospheric delay parameters.

Results

Conclusion