12 results on '"Huang, Guanwen"'
Search Results
2. Algorithm and Performance of Precipitable Water Vapor Retrieval Using Multiple GNSS Precise Point Positioning Technology
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Hu, Peng, Huang, Guanwen, Zhang, Qin, Wang, Xiaolei, Mao, Min, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Ruediger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Liang, Qilian, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Sun, Jiadong, editor, Yang, Changfeng, editor, and Guo, Shuren, editor
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- 2018
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3. Real-time cascading PPP-WAR based on Kalman filter considering time-correlation
- Author
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Jiang, Yang, Gao, Yuting, Zhou, Peiyuan, Gao, Yang, and Huang, Guanwen
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- 2021
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4. GNSS Dynamic PPP Based on Additional Priori Coordinate and Epoch Constraints Information
- Author
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Zang, Nan, Zhang, Qin, Li, Shijun, Huang, Guanwen, Zhang, Shuangcheng, Sun, Jiadong, editor, Jiao, Wenhai, editor, Wu, Haitao, editor, and Lu, Mingquan, editor
- Published
- 2014
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5. FCB estimation with three different PPP models: equivalence analysis and experiment tests
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Wang, Jin, Huang, Guanwen, Yang, Yuanxi, Zhang, Qin, Gao, Yang, and Xiao, Guorui
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- 2019
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6. Evaluation of Real-time Precise Point Positioning with Ambiguity Resolution Based on Multi-GNSS OSB Products from CNES.
- Author
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Du, Shi, Shu, Bao, Xie, Wei, Huang, Guanwen, Ge, Yulong, and Li, Pan
- Subjects
AMBIGUITY ,ROOT-mean-squares ,PRODUCT positioning - Abstract
Ambiguity resolution (AR) is a core technology that helps to speed up convergence time and increase positioning accuracy for precise point positioning (PPP), and the performance of PPP-AR is based on the quality of ambiguity resolution products. Real-time PPP-AR becomes a reality as users can now obtain publicly accessible real-time observable-specific signal bias (OSB) products from the Centre National d'Etudes Spatiales (CNES). Therefore, an analysis of the quality of OSB products and an evaluation of the performance of PPP-AR are required to promote the application of real-time positioning. For a total of 31 days between day of year (DOY) 121 and 151 in 2021, observation data were collected from 90 stations, and the OSB products were used to assess the experiments. As for the quality of the OSB products, the data availability (DA) of the GPS and Galileo satellites was greater than 97%, whereas that of BDS was less than 60%; the maximum fluctuation value (MAX) and standard deviation (STD) of the GPS, Galileo, and BDS satellites were 0.045 and 0.012; 0.081 and 0.028; and 0.292 and 0.085 cycles, respectively. In terms of ambiguity residuals using the OSB products, the wide-lane (WL) residual percentages within ±0.25 cycles for the GPS, Galileo, BDS-2, and BDS-3 systems were more than 92%, and the narrow-lane (NL) residual percentages within ±0.25 cycles for the four systems were 92%, 89%, 79%, and 60%, respectively. With regard to the performance of PPP-AR, the GPS+Galileo solution showed the best performance in the kinematic positioning mode, in which the mean root mean square (RMS) of positioning accuracy was 1.06, 1.27, and 2.85 cm for the east (E), north (N), and up (U) components, respectively, and the mean convergence time reached 9.6 min. In the static positioning mode, the mean convergence times of the GPS-only and GPS+Galileo solutions were 11.4 min and 8.0 min, respectively, and both of their mean RMS for positioning accuracy reached 0.79, 0.95, and 1.48 cm for the E, N, and U components, respectively. However, the addition of BDS did not further enhance the performance of multi-GNSS PPP-AR in either the kinematic or static positioning mode due to the poor quality of the real-time BDS products. More importantly, a prediction method was proposed to avoid re-convergence and to enhance the reliability of PPP-AR in the event of short-time missing real-time OSB products and to improve the positioning accuracy and the ambiguity fixed rate. [ABSTRACT FROM AUTHOR]
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- 2022
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7. On ionosphere-delay processing methods for single-frequency precise-point positioning
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Zhao Hong, Zhang Qin, Tu Rui, and Huang Guanwen
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Computer science ,lcsh:Geodesy ,mapping function ,Precise Point Positioning ,Tracking (particle physics) ,Physics::Geophysics ,single-frequency precise-point positioning ,Computers in Earth Sciences ,Earth-Surface Processes ,lcsh:QB275-343 ,ionosphere delay ,Estimation theory ,business.industry ,lcsh:QC801-809 ,Geodesy ,model correction ,Processing methods ,Model correction ,lcsh:Geophysics. Cosmic physics ,Geophysics ,Physics::Space Physics ,Global Positioning System ,Satellite ,Ionosphere ,parameter estimation ,business ,Algorithm - Abstract
In single-frequency precise-point positioning of a satellite, ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS (International GPS Service) tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.
- Published
- 2011
8. The research on carrier phase time transfer of BeiDou navigation satellite system
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Zhang Qin, Zhang Pengfei, Guang Wei, Li Wei, Huang Guanwen, Zhang Rui, and Yuan Haibo
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GNSS applications ,Computer science ,business.industry ,Real Time Kinematic ,BeiDou Navigation Satellite System ,Real-time computing ,Global Positioning System ,Time transfer ,Satellite navigation ,RINEX ,Precise Point Positioning ,business ,Remote sensing - Abstract
GPS/GLONASS Common view, all in view and PPP Time Transfer technology are widely used in the remote time comparison. With the benefit of the high precise measurement on carrier phase, the PPP time transfer technology which based on the carrier phase data has been used in the International time comparison for TAI computation. In this Paper, The Carrier Phase Time Transfer on BeiDou Navigation satellite system (BDS) is implemented. The technology is referenced with GPS carrier phase time transfer method Precise Point Position (PPP) and combined with dual-frequency observation from the BeiDou Navigation Satellite system. The broadcast ephemeris and precise orbits and clock data are used for calculation and comparison. The performance of this time transfer technology is analyzed on the respect of precise, frequency accuracy and stability. Compared with the BDS Common View and GPS Common View, the result of BeiDou carrier phase time transfer is verified and shows its better performance.
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- 2014
9. Multi-GNSS Combined Precise Point Positioning Using Additional Observations with Opposite Weight for Real-Time Quality Control.
- Author
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Fu, Wenju, Huang, Guanwen, Yang, Yuanxi, Zhang, Qin, Cui, Bobin, Ge, Maorong, and Schuh, Harald
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GLOBAL Positioning System , *QUALITY control , *BEIDOU satellite navigation system , *MOBILE geographic information systems , *GALILEO satellite navigation system - Abstract
The emergence of multiple global navigation satellite systems (multi-GNSS), including global positioning system (GPS), global navigation satellite system (GLONASS), Beidou navigation satellite system (BDS), and Galileo, brings not only great opportunities for real-time precise point positioning (PPP), but also challenges in quality control because of inevitable data anomalies. This research aims at achieving the real-time quality control of the multi-GNSS combined PPP using additional observations with opposite weight. A robust multiple-system combined PPP estimation is developed to simultaneously process observations from all the four GNSS systems as well as single, dual, or triple systems. The experiment indicates that the proposed quality control can effectively eliminate the influence of outliers on the single GPS and the multiple-system combined PPP. The analysis on the positioning accuracy and the convergence time of the proposed robust PPP is conducted based on one week's data from 32 globally distributed stations. The positioning root mean square (RMS) error of the quad-system combined PPP is 1.2 cm, 1.0 cm, and 3.0 cm in the east, north, and upward components, respectively, with the improvements of 62.5%, 63.0%, and 55.2% compared to those of single GPS. The average convergence time of the quad-system combined PPP in the horizontal and vertical components is 12.8 min and 12.2 min, respectively, while it is 26.5 min and 23.7 min when only using single-GPS PPP. The positioning performance of the GPS, GLONASS, and BDS (GRC) combination and the GPS, GLONASS, and Galileo (GRE) combination is comparable to the GPS, GLONASS, BDS and Galileo (GRCE) combination and it is better than that of the GPS, BDS, and Galileo (GCE) combination. Compared to GPS, the improvements of the positioning accuracy of the GPS and GLONASS (GR) combination, the GPS and Galileo (GE) combination, the GPS and BDS (GC) combination in the east component are 53.1%, 43.8%, and 40.6%, respectively, while they are 55.6%, 48.1%, and 40.7% in the north component, and 47.8%, 40.3%, and 34.3% in the upward component. [ABSTRACT FROM AUTHOR]
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- 2019
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10. Performance improvement of real-time PPP ambiguity resolution using a regional integer clock.
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Shu, Bao, Liu, Hui, Wang, Li, Huang, Guanwen, Zhang, Qin, and Yang, Zhixin
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INTEGERS , *AMBIGUITY , *PERFORMANCES , *SONICATION - Abstract
Obtaining reliable GNSS uncalibrated phase delay (UPD) or integer clock products is the key to achieving ambiguity-fixed solutions for real-time (RT) precise point positioning (PPP) users. However, due to the influence of RT orbit errors, the quality of UPD/integer clock products estimated with a globally distributed GNSS network is difficult to ensure, thereby affecting the ambiguity resolution (AR) performance of RT-PPP. In this contribution, by fully utilising the consistency of orbital errors in regional GNSS network coverage areas, a method is proposed for estimating regional integer clock products to compensate for RT orbit errors. Based on Centre National d'Études Spatiales (CNES) RT precise products, the regional GPS/BDS integer clock was estimated with a CORS network in the west of China. Results showed that the difference between the estimated regional and CNES global integer clock/bias products was generally less than 5 cm for GPS, whereas clock differences of greater than 10 cm were observed for BDS due to the large RT orbit error. Compared with PPP using global integer clock/bias products, the AR performance of PPP using the regional integer clock was obviously improved for four rover stations. For single GPS, the horizontal and vertical accuracies of ambiguity-fixed PPP solutions were improved by 56.2% and 45.3% on average, respectively, whereas improvements of 67.5% and 50.5% in the horizontal and vertical directions, respectively, were observed for the combined GPS/BDS situation. Based on a regional integer clock, the RMS error of a kinematic ambiguity-fixed PPP solution in the horizontal direction could reach 0.5 cm. In terms of initialisation time, the average time to first fix (TTFF) in combined GPS/BDS PPP was shortened from 18.2 min to 12.7 min. In view of the high AR performance realised with the use of regional integer clocks, this method can be applied to scenarios that require high positioning accuracy, such as deformation monitoring. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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11. Real-time estimation of BDS/GPS high-rate satellite clock offsets using sequential least squares.
- Author
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Fu, Wenju, Yang, Yuanxi, Zhang, Qin, and Huang, Guanwen
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REAL-time computing , *INTERPOLATION , *GLOBAL Positioning System , *GEOSTATIONARY satellites , *KALMAN filtering - Abstract
The real-time precise satellite clock product is one of key prerequisites for real-time Precise Point Positioning (PPP). The accuracy of the 24-hour predicted satellite clock product with 15 min sampling interval and an update of 6 h provided by the International GNSS Service (IGS) is only 3 ns, which could not meet the needs of all real-time PPP applications. The real-time estimation of high-rate satellite clock offsets is an efficient method for improving the accuracy. In this paper, the sequential least squares method to estimate real-time satellite clock offsets with high sample rate is proposed to improve the computational speed by applying an optimized sparse matrix operation to compute the normal equation and using special measures to take full advantage of modern computer power. The method is first applied to BeiDou Navigation Satellite System (BDS) and provides real-time estimation with a 1 s sample rate. The results show that the amount of time taken to process a single epoch is about 0.12 s using 28 stations. The Standard Deviation (STD) and Root Mean Square (RMS) of the real-time estimated BDS satellite clock offsets are 0.17 ns and 0.44 ns respectively when compared to German Research Center for Geosciences (GFZ) final clock products. The positioning performance of the real-time estimated satellite clock offsets is evaluated. The RMSs of the real-time BDS kinematic PPP in east, north, and vertical components are 7.6 cm, 6.4 cm and 19.6 cm respectively. The method is also applied to Global Positioning System (GPS) with a 10 s sample rate and the computational time of most epochs is less than 1.5 s with 75 stations. The STD and RMS of the real-time estimated GPS satellite clocks are 0.11 ns and 0.27 ns, respectively. The accuracies of 5.6 cm, 2.6 cm and 7.9 cm in east, north, and vertical components are achieved for the real-time GPS kinematic PPP. [ABSTRACT FROM AUTHOR]
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- 2018
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12. The realization and convergence analysis of combined PPP based on raw observation.
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Tu, Rui, Ge, Maorong, Zhang, Hongping, and Huang, Guanwen
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ASTRONOMICAL observations , *STOCHASTIC convergence , *IONOSPHERE , *CODING theory , *NUMERICAL analysis , *RELIABILITY in engineering , *PRECISION (Information retrieval) - Abstract
Abstract: In order to speed up Precise Point Positioning (PPP)’s convergence, a combined PPP method with GPS and GLONASS which is based on using raw observations is proposed, and the positioning results and convergence time have been compared with that of single system. The ionospheric delays and receiver’s Differential Code Bias (DCB) corrections are estimated as unknown parameters in this method. The numerical results show that the combined PPP has not caused significant impacts on the final solutions, but it greatly improved Position Dilution of Precision (PDOP) and convergence speed and enhanced the reliability of the solution. Meanwhile, the convergence speed is greatly influenced by the receiver’s DCB, positioning results in horizontal which are better than 10cm can be realized within 10min. In addition, the ionosphere and DCB products can be provided with high precision. [Copyright &y& Elsevier]
- Published
- 2013
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