BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP

The legacy Global Navigation Satellite System (GNSS) satellite clock offsets obtained by the dual-frequency undifferenced (UD) ionospheric-free (IF) model absorb the code and phase time-variant hardware delays, which leads to the inconsistency of the precise satellite clock estimated by different fr...

Full description

Saved in:
Bibliographic Details
Main Authors: Guoqiang Jiao, Ke Su, Min Fan, Yuze Yang, Huaquan Hu
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/16/23/4433
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850106741992194048
author Guoqiang Jiao
Ke Su
Min Fan
Yuze Yang
Huaquan Hu
author_facet Guoqiang Jiao
Ke Su
Min Fan
Yuze Yang
Huaquan Hu
author_sort Guoqiang Jiao
collection DOAJ
description The legacy Global Navigation Satellite System (GNSS) satellite clock offsets obtained by the dual-frequency undifferenced (UD) ionospheric-free (IF) model absorb the code and phase time-variant hardware delays, which leads to the inconsistency of the precise satellite clock estimated by different frequencies. The dissimilarity of the satellite clock offsets generated by different frequencies is called the inter-frequency clock bias (IFCB). Estimates of the IFCB typically employ epoch-differenced (ED) geometry-free ionosphere-free (GFIF) observations from global networks. However, this method has certain theoretical flaws by ignoring the receiver time-variant biases. We proposed a new undifferenced model coupled with satellite clock offsets, and further converted the IFCB into the code and phase time-variant mixed observable-specific signal bias (OSB) to overcome the defects of the traditional model and simplify the bias correction process of multi-frequency precise point positioning (PPP). The new model not only improves the mixed OSB performance, but also avoids the negative impact of the receiver time-variant biases on the satellite mixed OSB estimation. The STD and RMS of the original OSB can be improved by 7.5–60.9% and 9.4–66.1%, and that of ED OSB (it can reflect noise levels) can be improved by 50.0–87.5% and 60.0–88.9%, respectively. Similarly, the corresponding PPP performance for using new mixed OSB is better than that of using the traditional IFCB products. Thus, the proposed pseudorange and phase time-variant mixed OSB concept and the new undifferenced model coupled with satellite clock offsets are reliable, applicable, and effective in multi-frequency PPP.
format Article
id doaj-art-a585ad1904664eda8d7687e21728fc25
institution OA Journals
issn 2072-4292
language English
publishDate 2024-11-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj-art-a585ad1904664eda8d7687e21728fc252025-08-20T02:38:45ZengMDPI AGRemote Sensing2072-42922024-11-011623443310.3390/rs16234433BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPPGuoqiang Jiao0Ke Su1Min Fan2Yuze Yang3Huaquan Hu4Beijing Institute of Tracking and Telecommunications Technology, Beijing 100094, ChinaDepartment of Space Information, Space Engineering University, Beijing 101416, ChinaBeijing Institute of Tracking and Telecommunications Technology, Beijing 100094, ChinaShanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, ChinaDepartment of Space Information, Space Engineering University, Beijing 101416, ChinaThe legacy Global Navigation Satellite System (GNSS) satellite clock offsets obtained by the dual-frequency undifferenced (UD) ionospheric-free (IF) model absorb the code and phase time-variant hardware delays, which leads to the inconsistency of the precise satellite clock estimated by different frequencies. The dissimilarity of the satellite clock offsets generated by different frequencies is called the inter-frequency clock bias (IFCB). Estimates of the IFCB typically employ epoch-differenced (ED) geometry-free ionosphere-free (GFIF) observations from global networks. However, this method has certain theoretical flaws by ignoring the receiver time-variant biases. We proposed a new undifferenced model coupled with satellite clock offsets, and further converted the IFCB into the code and phase time-variant mixed observable-specific signal bias (OSB) to overcome the defects of the traditional model and simplify the bias correction process of multi-frequency precise point positioning (PPP). The new model not only improves the mixed OSB performance, but also avoids the negative impact of the receiver time-variant biases on the satellite mixed OSB estimation. The STD and RMS of the original OSB can be improved by 7.5–60.9% and 9.4–66.1%, and that of ED OSB (it can reflect noise levels) can be improved by 50.0–87.5% and 60.0–88.9%, respectively. Similarly, the corresponding PPP performance for using new mixed OSB is better than that of using the traditional IFCB products. Thus, the proposed pseudorange and phase time-variant mixed OSB concept and the new undifferenced model coupled with satellite clock offsets are reliable, applicable, and effective in multi-frequency PPP.https://www.mdpi.com/2072-4292/16/23/4433inter-frequency clock bias (IFCB)observable-specific signal bias (OSB)epoch-differenced (ED)undifferencedmulti-frequency precise point positioning
spellingShingle Guoqiang Jiao
Ke Su
Min Fan
Yuze Yang
Huaquan Hu
BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
Remote Sensing
inter-frequency clock bias (IFCB)
observable-specific signal bias (OSB)
epoch-differenced (ED)
undifferenced
multi-frequency precise point positioning
title BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
title_full BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
title_fullStr BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
title_full_unstemmed BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
title_short BDS-3/GNSS Undifferenced Pseudorange and Phase Time-Variant Mixed OSB Considering the Receiver Time-Variant Biases and Its Benefit on Multi-Frequency PPP
title_sort bds 3 gnss undifferenced pseudorange and phase time variant mixed osb considering the receiver time variant biases and its benefit on multi frequency ppp
topic inter-frequency clock bias (IFCB)
observable-specific signal bias (OSB)
epoch-differenced (ED)
undifferenced
multi-frequency precise point positioning
url https://www.mdpi.com/2072-4292/16/23/4433
work_keys_str_mv AT guoqiangjiao bds3gnssundifferencedpseudorangeandphasetimevariantmixedosbconsideringthereceivertimevariantbiasesanditsbenefitonmultifrequencyppp
AT kesu bds3gnssundifferencedpseudorangeandphasetimevariantmixedosbconsideringthereceivertimevariantbiasesanditsbenefitonmultifrequencyppp
AT minfan bds3gnssundifferencedpseudorangeandphasetimevariantmixedosbconsideringthereceivertimevariantbiasesanditsbenefitonmultifrequencyppp
AT yuzeyang bds3gnssundifferencedpseudorangeandphasetimevariantmixedosbconsideringthereceivertimevariantbiasesanditsbenefitonmultifrequencyppp
AT huaquanhu bds3gnssundifferencedpseudorangeandphasetimevariantmixedosbconsideringthereceivertimevariantbiasesanditsbenefitonmultifrequencyppp