Article
Engineering, Aerospace
Sermet Ogutcu, Salih Alcay, Behlul Numan Ozdemir, Pan Li, Yize Zhang, Ceren Konukseven, Omer Faruk Atiz
Summary: This study investigates the contribution of BDS-3 FOC to GPS + GLONASS + Galileo (GRE) PPP-AR, considering different cutoff angles and observation session lengths. The results show that BDS-3 degrades the horizontal and vertical accuracy of static GRE PPP-AR solutions, except for 24-hour sessions. However, BDS-3 significantly contributes to the accuracy of GRE kinematic PPP-AR for certain cutoff angles. The convergence time analysis indicates that BDS-3 only contributes to the vertical component of GRE kinematic PPP-AR.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Rui Tu, Pengfei Zhang, Rui Zhang, Lihong Fan, Junqiang Han, Ju Hong, Jinhai Liu, Xiaochun Lu
Summary: The study proposes a real-time and dynamic time transfer method based on double-differenced (DD) GNSS observations, which fixes ambiguities and achieves time transfer using single-differenced (SD) observations. Validation results demonstrate that the method provides better accuracy and stability for positioning and time transfers compared to undifferenced methods, making it more suitable for real-time applications.
IET RADAR SONAR AND NAVIGATION
(2021)
Article
Chemistry, Analytical
Lei Zhao, Paul Blunt, Lei Yang, Sean Ince
Summary: In this study, the performance of real-time GPS/Galileo zero-difference ionosphere-free (IF) precise point positioning (PPP) and inertial navigation system (INS) integration was investigated. The use of uncombined bias products, which were independent of PPP modeling on the user side, enabled carrier phase ambiguity resolution (AR). The results showed that in the train test, ambiguity-float PPP had similar performance with PPP/INS integration, and after AR, significant improvements were achieved. In the van tests, TCI achieved the highest accuracies and effectively eliminated solution re-convergence in PPP.
Article
Environmental Sciences
Jian Tang, Daqian Lyu, Fangling Zeng, Yulong Ge, Runzhi Zhang
Summary: This article evaluates the quality of PPP-B2b products and compares them with products from CNES and DCBs from CAS. It also conducts a comprehensive performance evaluation of PPP time transfer based on the PPP-B2b service, comparing and assessing different solutions. The results show that BDS-3 satellites have better orbit and clock offset quality than GPS satellites for PPP-B2b products. The accuracy of B2b-RTPPP is improved with DCB correction, and different solutions have varying frequency stability.
Article
Engineering, Aerospace
Zhiling Ren, Hang Gong, Jing Peng, Chengpan Tang, Xinming Huang, Guangfu Sun
Summary: The paper evaluates the performance of China's BeiDou Navigation Satellite System in real-time precise point positioning, showing high orbit and clock offset accuracy, as well as good agreement with differential code bias parameters of MGEX. The positioning accuracy performs well in both static and dynamic modes.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Engineering, Multidisciplinary
Wenju Fu, Jin Wang, Lei Wang, Ruizhi Chen
Summary: This study proposes a Kalman filter-based online fractional cycle bias (FCB) determination method for real-time integer ambiguity resolution in satellite clock estimation. By smoothing the float wide-lane ambiguity and implementing quality control procedures, the method improves estimation accuracy and convergence. Validation results show significant improvement in real-time positioning accuracy.
Article
Geochemistry & Geophysics
A. Sa, W. Rohm, R. M. Fernandes, E. Trzcina, M. Bos, F. Bento
Summary: The signal from GNSS satellites can be utilized to estimate the amount of water vapor in the atmosphere, helping improve weather forecast quality and speed. SWART software employs algebraic reconstruction techniques to quickly estimate water vapor content, with validation from data at Polish stations demonstrating its feasibility and accuracy in weather predictions.
JOURNAL OF GEODESY
(2021)
Article
Engineering, Multidisciplinary
Chenhao Ouyang, Junbo Shi, Yongshuai Huang, Jiming Guo, Chaoqian Xu
Summary: This study analyzed the real-time orbit/clock products of BDS and found that CNE had the best 3D orbit correction accuracy and clock offset precision, while DLR had the largest orbit errors and worst clock precision. Overall, WHU/GFZ/CNE's real-time corrections showed satisfactory orbit/clock performance and were recommended for BDS-2 real-time PPP.
Article
Engineering, Aerospace
Engin Tunali
Summary: Precise Point Positioning (PPP) is a cost-effective and efficient technique for monitoring precipitable water vapor (PWV). In this study, the quality of real-time PPP-derived PWVs is evaluated and compared with precipitation estimates from different global products, demonstrating a high level of agreement between the estimated PWVs and other measurements.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Engineering, Multidisciplinary
Haitao Zhou, Lei Wang, Wenju Fu, Yi Han, Tao Li, Wei Li, Ruizhi Chen
Summary: This study investigates the performance of BDS-3 PPP-B2b services in dual-frequency precise point positioning and evaluates the benefits of this service for single-frequency users. The results show that applying PPP-B2b corrections can achieve high orbit and clock accuracy, and the performance of PPP-B2b augmented SF-PPP is also satisfactory in both static and kinematic scenarios.
Article
Environmental Sciences
Xia Xiao, Fei Shen, Xiaochun Lu, Pengli Shen, Yulong Ge
Summary: Single-frequency (SF) receivers are cheaper and have simpler hardware delay calibration compared to dual-frequency (DF) receivers. Studying the possibility of time transfer using SF PPP, it is found that real-time single-frequency PPP can meet time transfer requirements effectively.
Article
Geochemistry & Geophysics
Xiao Yin, Hongzhou Chai, Wenbing Xu, Liang Zhao, Huawei Zhu
Summary: Real-time kinematic (RTK) technology is widely used for high-precision positioning in the offshore area. However, its mass-market applications are limited due to the need for bi-directional communication and error grouping. PPP-RTK, combining precise point positioning (PPP) and RTK, has become a hotspot technology in the mass market. In this contribution, an uncombined multi-GNSS PPP-RTK model is proposed, using uncalibrated phase delays estimated from legacy ionosphere-free and Melbourne-Wubbena combination. By conducting PPP ambiguity resolution (AR) and deriving precise atmospheric corrections, the positioning accuracy in the offshore area can be improved to a level similar to RTK.
Article
Instruments & Instrumentation
Atanu Santra, Sukabya Dan, P. Banerjee, Surajit Kundu, Anindya Bose
Summary: A novel method utilizing PPP time transfer technique is proposed in this paper to assess the timing performance of NavIC receiver, with indirect access to the BIPM time transfer data bank. The uncertainty (1 sigma) of the measurement of NavIC receiver bias has been found to be 11 ns.
MAPAN-JOURNAL OF METROLOGY SOCIETY OF INDIA
(2022)
Article
Geochemistry & Geophysics
Caoming Fan, Zheng Yao, Shengli Wang, Jianping Xing
Summary: GNSS PPP augmented with PLS significantly improves positioning accuracy, convergence speed, and success rate of ambiguity resolution.
JOURNAL OF GEODESY
(2022)
Article
Environmental Sciences
Lizhong Qu, Pu Zhang, Changfeng Jing, Mingyi Du, Jian Wang, Qile Zhao, Juanjuan Li
Summary: This study investigates the estimation of fractional cycle biases (FCBs) for GPS triple-frequency PPP with AR based on IGU and IGF orbits. It finds that IGU orbit errors significantly impact NL FCBs, while EWL and WL FCBs remain stable. The use of IGU orbits results in longer TTFF and lower fixing rates compared to IGF orbits.
