An Improved Fast Estimation of Satellite Phase Fractional Cycle Biases

Ke Qi,Ke Qi,Changhui Xu,Shouzhou Gu,Yamin Dang

doi:10.3390/rs14020334

Abstract

Satellite phase fractional cycle biases (FCBs) are crucial to precise point positioning with ambiguity resolution (PPP–AR), and they can improve the accuracy and reliability of a solution. Traditional methods need multiple iterations and need to keep the same reference when estimating satellite phase fractional cycle biases. In this paper, we propose an improved fast estimation of FCB, which does not need any iterations and can select any reference when estimating FCB. We compare the suitability and precision of a traditional and a proposed method by BDS-3 experiments. The results of the FCB experiments show that the calculated time of the proposed method is less than the traditional method and that computation efficiency is increased by 34.71%. These two methods have a similar rate of fixed epochs and ambiguities in the static and dynamic models. However, the time to first fix (TTFF) of the proposed method decreased by 19.69% and 28.83% for the static and dynamic models, respectively. The results show that the proposed method has a better convergence time in PPP–AR.

Highlights

Satellite Phase Fractional CycleThe International Geodesy Service (IGS) is an international organization established by the International Association of Geodesy to support geodetic and geodynamic research
In order to analyze the performance of the proposed method, we used the observation data of Multi-GNSS Experiment (MGEX) station in 2021 to estimate BDS-3 WL and NL fractional cycle biases (FCBs)
The traditional initial value is equivalent to setting a receiver FCB to zero when selecting the reference of NL FCB

Summary

Introduction

The International Geodesy Service (IGS) is an international organization established by the International Association of Geodesy to support geodetic and geodynamic research. In the mid-1990s, IGS began to provide precise orbit and clock products for users around the world, which made it possible for the realization of PPP based on an undifferenced model. Zumberge et al [1] realized a centimeter-level static PPP through the ionosphere-free (IF). Combined model, which used precise ephemeris and clock products provided by IGS. It was verified through experiments that it is completely feasible to use undifferenced observations for PPP in theory. Héroux et al [2] obtained centimeter-level positioning accuracy by using a dual-frequency ionosphere-free (IF) combined model in PPP. Ye et al [3] analyzed the PPP models and discussed the final and real-time PPP models based on a network

Methods

Results

Discussion

Conclusion