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Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution

It is difficult to enable traditional precise point positioning (PPP) with ambiguity resolution (AR) due to fractional cycle biases (FCBs), which limit the accuracy and reliability of positioning results. The BeiDou Navigation Satellite System (BDS) has been providing continuous positioning, navigat...

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Autores principales: Jiang, Weiping, Zhao, Wen, Chen, Hua, Liu, Xuexi, An, Xiangdong, Chen, Qusen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864641/
https://www.ncbi.nlm.nih.gov/pubmed/31683514
http://dx.doi.org/10.3390/s19214725
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author Jiang, Weiping
Zhao, Wen
Chen, Hua
Liu, Xuexi
An, Xiangdong
Chen, Qusen
author_facet Jiang, Weiping
Zhao, Wen
Chen, Hua
Liu, Xuexi
An, Xiangdong
Chen, Qusen
author_sort Jiang, Weiping
collection PubMed
description It is difficult to enable traditional precise point positioning (PPP) with ambiguity resolution (AR) due to fractional cycle biases (FCBs), which limit the accuracy and reliability of positioning results. The BeiDou Navigation Satellite System (BDS) has been providing continuous positioning, navigation, and timing (PNT) services in the global region since the end of 2018. The BDS constellation includes geostationary earth orbit (GEO), inclined geostationary orbit (IGSO), and medium earth orbit (MEO) satellites. However, its hybrid constellation structure and the satellite-side multipath effect have hindered the BDS PPP AR for two main reasons: (1) some receivers have half-cycle biases between GEO and non-GEO satellites, which result in the inconsistency of hardware delays for each satellite type; (2) the correction model for elevation-dependent satellite-side multipath effect is only applicable to IGSO and MEO, while in the case of GEO the effect cannot be effectively weakened or eliminated. To rectify these problems, a suitable strategy is proposed for estimating BDS FCBs, whereby the GEO FCBs and non-GEO FCBs are estimated independently. Results show that the FCBs estimated by the new strategy for GEO and non-GEO are more stable compared to the traditional strategy. The GEO wide-lane (WL) FCBs fluctuate less than 0.3 cycle in one month, except for C05, while the variation of non-GEO WL FCBs is about 0.1 cycle. In addition, compared to the traditional strategy, the fractions of GEO WL ambiguities after the removal of FCBs estimated by the new strategy can be improved noticeably from 53.5% to 78.5%, and from 71.8% to 92.3% for <0.15 cycle and <0.25 cycle respectively, which could be comparable with non-GEO. Simultaneously, the improvement of GEO narrow-lane (NL) ambiguities is from 28.9% to 40.2%, and from 40.4% to 53.3% for <0.10 cycle and <0.15 cycle respectively, are less noticeable. This is mainly due to the low precision IGS products for GEO. After PPP AR, the mean convergence time is shorted from 56.0 min to 43.6 min, and from 71.6 min to 62.7 min for static PPP and kinematic PPP, respectively.
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spelling pubmed-68646412019-12-23 Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution Jiang, Weiping Zhao, Wen Chen, Hua Liu, Xuexi An, Xiangdong Chen, Qusen Sensors (Basel) Article It is difficult to enable traditional precise point positioning (PPP) with ambiguity resolution (AR) due to fractional cycle biases (FCBs), which limit the accuracy and reliability of positioning results. The BeiDou Navigation Satellite System (BDS) has been providing continuous positioning, navigation, and timing (PNT) services in the global region since the end of 2018. The BDS constellation includes geostationary earth orbit (GEO), inclined geostationary orbit (IGSO), and medium earth orbit (MEO) satellites. However, its hybrid constellation structure and the satellite-side multipath effect have hindered the BDS PPP AR for two main reasons: (1) some receivers have half-cycle biases between GEO and non-GEO satellites, which result in the inconsistency of hardware delays for each satellite type; (2) the correction model for elevation-dependent satellite-side multipath effect is only applicable to IGSO and MEO, while in the case of GEO the effect cannot be effectively weakened or eliminated. To rectify these problems, a suitable strategy is proposed for estimating BDS FCBs, whereby the GEO FCBs and non-GEO FCBs are estimated independently. Results show that the FCBs estimated by the new strategy for GEO and non-GEO are more stable compared to the traditional strategy. The GEO wide-lane (WL) FCBs fluctuate less than 0.3 cycle in one month, except for C05, while the variation of non-GEO WL FCBs is about 0.1 cycle. In addition, compared to the traditional strategy, the fractions of GEO WL ambiguities after the removal of FCBs estimated by the new strategy can be improved noticeably from 53.5% to 78.5%, and from 71.8% to 92.3% for <0.15 cycle and <0.25 cycle respectively, which could be comparable with non-GEO. Simultaneously, the improvement of GEO narrow-lane (NL) ambiguities is from 28.9% to 40.2%, and from 40.4% to 53.3% for <0.10 cycle and <0.15 cycle respectively, are less noticeable. This is mainly due to the low precision IGS products for GEO. After PPP AR, the mean convergence time is shorted from 56.0 min to 43.6 min, and from 71.6 min to 62.7 min for static PPP and kinematic PPP, respectively. MDPI 2019-10-31 /pmc/articles/PMC6864641/ /pubmed/31683514 http://dx.doi.org/10.3390/s19214725 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Jiang, Weiping
Zhao, Wen
Chen, Hua
Liu, Xuexi
An, Xiangdong
Chen, Qusen
Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title_full Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title_fullStr Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title_full_unstemmed Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title_short Analysis of BDS Fractional Cycle Biases and PPP Ambiguity Resolution
title_sort analysis of bds fractional cycle biases and ppp ambiguity resolution
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864641/
https://www.ncbi.nlm.nih.gov/pubmed/31683514
http://dx.doi.org/10.3390/s19214725
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