Three Dual-Frequency Precise Point Positioning Models for the Ionospheric Modeling and Satellite Pseudorange Observable-Specific Signal Bias Estimation

Ke Su,Shuanggen Jin

doi:10.3390/rs13245093

Abstract

Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) enables the estimation the ionospheric vertical total electron content (VTEC) as well as the by-product of the satellite Pseudorange observable-specific signal bias (OSB). The single-frequency PPP models, with the ionosphere-float and ionosphere-free approaches in ionospheric studies, have recently been discussed by the authors. However, the multi-frequency observations can improve the performances of the ionospheric research compared with the single-frequency approaches. This paper presents three dual-frequency PPP approaches using the BeiDou Navigation Satellite System (BDS) B1I/B3I observations to investigate ionospheric activities. Datasets collected from the globally distributed stations are used to evaluate the performance of the ionospheric modeling with the ionospheric single- and multi-layer mapping functions (MFs), respectively. The characteristics of the estimated ionospheric VTEC and BDS satellite pseudorange OSB are both analyzed. The results indicated that the three dual-frequency PPP models could all be applied to the ionospheric studies, among which the dual-frequency ionosphere-float PPP model exhibits the best performance. The three dual-frequency PPP models all possess the capacity for ionospheric applications in the GNSS community.

Highlights

IntroductionSince the ionosphere is a dispersive medium, the ionospheric delay can be eliminated by multi-frequency observations
The results indicate that the accuracy of the ionospheric vertical total electron content (VTEC)
DFPPP1, and models are presented for ionospheric studies.studies

Summary

Introduction

Since the ionosphere is a dispersive medium, the ionospheric delay can be eliminated by multi-frequency observations. Single-frequency GNSS users require external ionospheric information to eliminate the ionospheric delay. One commonly applied way is to use the empirical models such as the Klobuchar, NeQuick, BDGIM, NTCM and so on [6,7,8,9,10]. Another alternative way is to apply the ionospheric TEC map obtained from the globally distributed stations

Methods

Results

Conclusion