Performance of BDS-2/3, GPS, and Galileo Time Transfer with Real-Time Single-Frequency Precise Point Positioning

Xia Xiao,Xiaochun Lu,Yulong Ge,Pengli Shen,Fei Shen

doi:10.3390/rs13214192

Abstract

Single-frequency (SF) receivers are much cheaper than that of dual-frequency (DF). Even though DF precise point positioning (PPP) is nowadays applied in the time community, the cost of equipment is one of the key considerations for time users. Furthermore, the hardware delay calibration of single-frequency devices is simpler than that of dual-frequency devices. In addition, there is no literature to study real-time SF PPP time transfer. In this contribution, the possibility of time transfer using SF PPP was studied. The Un-combined SF PPP was employed for time transfer with ionospheric-constraint using real-time precise products. In this case, 18 multi-GNSS experiment (MGEX) stations and one time lab station were used to study real-time SF PPP time transfer using GPS, Galileo and BDS-2/3 satellites with 20-day. The results suggested that real-time single-frequency PPP can meet time transfer. the standard deviation (STD) of the clock difference obtained from GPS-only, Galileo-only and BDS-2/3 single-frequency PPP are about (0.51, 0.54, 0.91) ns, respectively. The frequency stability of real-time single-frequency PPP can achieve (1E-12, 1E-13, 1E-13) level at short-term and (1E-13, 1E-13, 1E-14) level at long-term, respectively, for BDS-2/3, Galileo-only and GPS-only based.

Highlights

GNSS technique is a reliable and effective tool for time transfer in the time community, due to its all-weather, high precision and other characteristics [1,2,3,4,5]
The results presented that quad-frequency precise point positioning (PPP) model can enhance the reliability and redundancy of time transfer compared to dual-frequency model
Real-time single-frequency PPP technique is employed to time transfer using BDS-2/3, Galileo- and GPS-only satellites

Summary

Introduction

GNSS technique is a reliable and effective tool for time transfer in the time community, due to its all-weather, high precision and other characteristics [1,2,3,4,5]. Even though the receiver clock offset parameter is estimated from GNSS data, GNSS has been generally regarded as one of the most accurate time transfer technologies [6,7]. GNSS time transfer techniques can be divided into two schemes as time transfer with pseudorange observations or with carrier phase observations, respectively [3,8]. In pseudorange observation-based scheme, CV, AV and TWSTFT [9] are representative time transfer technologies, with the accuracy of time transfer up to nanoseconds levels. The accuracy of above technologies is subject to pseudorange observations. In carrier phase and pseudorange observation-based scheme, PPP is one of the most accurate technologies for time transfer, which can reach sub-nanoseconds levels.

Methods

Results

Conclusion