Abstract
The Chinese Beidou navigation satellite system (BDS) has provided regional and global navigation and positioning services for the users via the BDS-2 and BDS-3 satellites. However, BDS-2 and BDS-3 send navigation signals on different frequencies; three of those are identical to assure system compatibility and interoperability. To comparatively analyze these navigation signals, we carried out three zero-baseline experiments with five brands of receivers, including Trimble, Septentrio, NovAtel, ComNav and Unicore. BDS-2 and BDS-3 multi-frequency data were collected during these experiments. The data were processed to evaluate the code and carrier phase measurement noises and investigate the inter-system biases (ISBs) on the three identical frequencies. The effects of the ISB on ambiguity resolution (AR) and position estimation (PE) were also demonstrated using the zero-baseline data with one Trimble receiver and one Septentrio receiver. The results show some new findings: (1) the code and phase noises in BDS-3 are smaller than those in BDS-2 on the same frequencies, and the three new signals B1C, B2b and B2a have comparable noises to the present signals. Besides, millimeter-level code noises are achieved on B3I and B2a signals in NovAtel receivers; (2) the code ISBs on B1I, B2I/B2b and B3I between BDS-2 and BDS-3 were found and distinguished, while no phase ISB could be found. The code ISB seems to be receiver-related and can be as large as 1 m in heterogeneous receivers. It is stable during a whole day but may also vary due to a restart of the receiver. No code and phase ISB on all three frequencies is observed for homogeneous receivers; (3) the code ISB will hamper the reliable AR and precise PE. The HMW (Hatch–Melbourne–Wübbena) combination on B1I and B3I is severely biased by about 0.6 cycles when double differencing between BDS-2 and BDS-3. After ISB calibration, the ratio value of wide-lane (WL) AR has a slight increase, and the accuracy of DD B1I code positioning has improved more than 10%, but few improvements can be seen in the fixed solution. It should be noted that although the inter-system code bias (ISCB) between BDS-2 and BDS-3 is detected in the baseline data, this bias should be considered in the absolute positioning as well.
Similar content being viewed by others
Data availability
The zero-baseline observation data of three different whole days in this study are available from the corresponding author for academic purposes on reasonable request.
References
CSNO (2017a) BeiDou Navigation Satellite System Signal in Space Interface Control Document: Open Service Signal B1C (Version 1.0)
CSNO (2017b) BeiDou Navigation Satellite System Signal in Space Interface Control Document: Open Service Signal B2a (Version 1.0)
CSNO (2020a) Completion and Commissioning of the BeiDou Navigation Satellite System (BDS-3). http://en.beidou.gov.cn/WHATSNEWS/202008/t20200803_21013.html.
CSNO (2020b) BeiDou Navigation Satellite System Signal in Space Interface Control Document: Open Service Signal B2b (Version 1.0)
Deng C, Liu Q, Zou X, Tang W, Cui J, Wang Y, Guo C (2020) Investigation of tightly combined single-frequency and single-epoch precise positioning using multi-GNSS data. Remote Sens 12(2):285. https://doi.org/10.3390/rs12020285
Hatch R (1982) The synergism of GPS code and carrier measurements. In: Proceedings of the third international symposium on satellite doppler positioning, physical sciences Laboratory of New Mexico State University, Feb 8–12, pp 1213–1231
Jiao G, Song S, Liu Y, Su K, Cheng N, Wang S (2020) Analysis and assessment of BDS-2 and BDS-3 broadcast ephemeris: accuracy, the datum of broadcast clocks and its impact on single point positioning. Remote Sens 12(13):2081. https://doi.org/10.3390/rs12132081
Lu M, Li W, Yao Z, Cui X (2019) Overview of BDS III new signals. Navigation 66(1):19–35. https://doi.org/10.1002/navi.296
Lv Y, Geng T, Zhao Q, Xie X, Zhou R (2020) Initial assessment of BDS-3 preliminary system signal-in-space range error. GPS Solut 24(1):16. https://doi.org/10.1007/s10291-019-0928-x
Melbourne W (1985) The case for ranging in GPS based geodetic systems. In: Proceedings of the first symposium on precise positioning with the global positioning system, Positioning with GPS-1985, U.S. Department of Commerce, Rockville, Md, pp 373–386
Mi X, Zhang B, Yuan Y (2019) Multi-GNSS inter-system biases: estimability analysis and impact on RTK positioning. GPS Solut 23(3):81. https://doi.org/10.1007/s10291-019-0873-8
Odijk D, Nadarajah N, Zaminpardaz S, Teunissen PJG (2017) GPS, Galileo, QZSS and IRNSS differential ISBs: estimation and application. GPS Solut 21(2):439–450. https://doi.org/10.1007/s10291-016-0536-y
Shi J, Ouyang C, Huang Y, Peng W (2020) Assessment of BDS-3 global positioning service: ephemeris, SPP, PPP, RTK, and new signal. GPS Solut 24(3):81. https://doi.org/10.1007/s10291-020-00995-y
Teunissen PJG (1995) The least-squares ambiguity decorrelation adjustment: a method for fast GPS integer ambiguity estimation. J Geodesy 70(1):65–82. https://doi.org/10.1007/BF00863419
Wanninger L, Beer S (2015) BeiDou satellite-induced code pseudorange variations: diagnosis and therapy. GPS Solut 19(4):639–648. https://doi.org/10.1007/s10291-014-0423-3
Wübbena G (1985) Software developments for geodetic positioning with GPS using TI- 4100 code and carrier measurements. In: Proceedings of the first symposium on precise positioning with the global positioning system, positioning with GPS-1985, U.S. Department of Commerce, Rockville, Md, pp 403–412
Wu M, Liu W, Wang W, Zhang X (2019) Differential inter-system biases estimation and initial assessment of instantaneous tightly combined RTK with BDS-3, GPS, and Galileo. Remote Sens 11(12):1430. https://doi.org/10.3390/rs11121430
Yang Y, Gao W, Guo S, Mao Y, Yang Y (2019) Introduction to BeiDou-3 navigation satellite system. Navigation 66(1):7–18. https://doi.org/10.1002/navi.291
Zhang Z, Li B, Nie L, Wei C, Jia S, Jiang S (2019) Initial assessment of BeiDou-3 global navigation satellite system: signal quality, RTK and PPP. GPS Solut 23(4):111. https://doi.org/10.1007/s10291-019-0905-4
Zhang X, Li X, Lu C, Wu M, Pan L (2019b) A comprehensive analysis of satellite-induced code bias for BDS-3 satellites and signals. Adv Space Res 63(9):2822–2835. https://doi.org/10.1016/j.asr.2017.11.031
Zhang Y, Kubo N, Chen J, Wang J, Wang H (2019c) Initial positioning assessment of BDS new satellites and new signals. Remote Sens 11(11):1320. https://doi.org/10.3390/rs11111320
Zhao W, Chen H, Gao Y, Jiang W, Liu X (2020) Evaluation of inter-system bias between BDS-2 and BDS-3 satellites and its impact on precise point positioning. Remote Sens 12(14):2185. https://doi.org/10.3390/rs12142185
Zhou R, Hu Z, Zhao Q, Li P, Wang W, He C, Cai C, Pan Z (2018) Elevation-dependent pseudorange variation characteristics analysis for the new-generation BeiDou satellite navigation system. GPS Solut 22(3):60. https://doi.org/10.1007/s10291-018-0726-x
Acknowledgements
This work is sponsored partially by the Joint Fund of Ministry of Education of China for Equipment Pre-research (Grant Nos. 6141A02011907, 6141A02022372) and partially by the National Natural Science Foundation of China (Grant Nos. 41804028, 41874037). Mr. Yongfeng Zhang in Wuhan Panda Space Time Technology Co., Ltd. provides the prototype receivers with the NovAtel, ComNav and Unicore OEM boards; the authors are grateful for his help. In addition, we also thank the anonymous reviewers for constructive comments, which help improve the quality of this paper.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Deng, C., Qi, S., Li, Y. et al. A comparative analysis of navigation signals in BDS-2 and BDS-3 using zero-baseline experiments. GPS Solut 25, 143 (2021). https://doi.org/10.1007/s10291-021-01178-z
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10291-021-01178-z