References of "Yuan, Yunbin"
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See detailEvaluation of a regional real-time precise positioning system based on GPS/BeiDou observations in Australia
Ding, Wenwu UL; Tan, Bingfeng; Chen, Yongchang et al

in Advances in Space Research (2018)

The performance of real-time (RT) precise positioning can be improved by utilizing observations from multiple Global Navigation Satellite Systems (GNSS) instead of one particular system. Since the end of ... [more ▼]

The performance of real-time (RT) precise positioning can be improved by utilizing observations from multiple Global Navigation Satellite Systems (GNSS) instead of one particular system. Since the end of 2012, BeiDou, independently established by China, began to provide operational services for users in the Asia-Pacific regions. In this study, an regional RT precise positioning system in Australia is developed to evaluate the performance of GPS/BeiDou observations in providing high precision positioning services for users. Fixing three hourly updated satellite orbits, RT correction messages are generated and broadcasted by processing RT observation/navigation data streams from AUSCORS at the server side. At the user side, RT PPP is realized by processing RT data streams and the RT correction messages received. RT clock offsets, for which the accuracy reached 0.07 and 0.25 ns for GPS and BeiDou, respectively, can be determined. Based on these corrections, an accuracy of 12.2, 30.0 and 45.6 cm in the North, East and Up directions was achieved for the BeiDou-only solution after 30 minutes while the GPS-only solution reached 5.1, 15.3 and 15.5 cm for the same components at the same time. A further improvement of 43.7, 36.9 and 45.0 percent in the three directions, respectively, was achieved for the combined GPS/BeiDou solution. After the initialization process, the North, East and Up positioning accuracies were 5.2, 8.1 and 17.8 cm, respectively, for the BeiDou-only solution, while 1.5, 3.0, and 4.7 cm for the GPS-only solution. However, we only noticed a 20.9% improvement in the East direction was obtained for the GPS/BeiDou solution, while no improvements in the other directions were detected. It is expected that such improvements may become bigger with the increasing accuracy of the BeiDou-only solution. [less ▲]

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See detailAn Evaluaton of Real-Time Troposphere Products Based on mult-GNSS Precise Point Posi)oning
Ding, Wenwu; Teferle, Felix Norman UL; Kazmierski, Kamil et al

Scientific Conference (2017, February 21)

When employing observations from multiple Global Navigation Satellite System (GNSS) the performance of real-time (RT) GNSS meteorology can be improved. In this paper, we describe an operational RT system ... [more ▼]

When employing observations from multiple Global Navigation Satellite System (GNSS) the performance of real-time (RT) GNSS meteorology can be improved. In this paper, we describe an operational RT system for extracting zenith tropospheric delay (ZTD) using a modified version of the PPP-wizard. Multi-GNSS, including GPS, GLONASS and Galileo, observation streams are processed using a RT PPP strategy based on RT satellite orbit/clock products from CNES. A continuous experiment for 30 days is conducted, in which the RT observation streams of 20 globally distributed stations are processed. The initialization time and accuracy of the RT troposphere products using single/multi-system observations are evaluated. The effect of RT PPP ambiguity resolution is also evaluated. The results reveal that the RT troposphere products based on single system observations can fulfill the requirements of meteorological application, in which the GPS-only solution is better than the GLONASS-only solution in both initialization and accuracy. The performance can also be improved by applying RT PPP ambiguity resolution and utilizing multi-GNSS observations. Specifically, we notice that the ambiguity resolution is more effective in improving the accuracy, whereas the initialization process can be better accelerated by multi-GNSS observations. Combining all systems, RT troposphere products with an average accuracy of about 8 mm in ZTD can be achieved after an initialization process of approximately 9 minutes, which supports the application of multi-GNSS observations and ambiguity resolution for RT meteorological applications. [less ▲]

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See detailAn evaluation of real-time troposphere estimation based on GNSS Precise Point Positioning
Ding, Wenwu; Teferle, Felix Norman UL; Kazmierski, Kamil et al

in Journal of Geophysical Research: Atmospheres (2017), 122(5), 2779--2790

It is anticipated that the performance of real-time (RT) GNSS meteorology can be further improved by incorporating observations from multiple Global Navigation Satellite System (GNSS), including GPS ... [more ▼]

It is anticipated that the performance of real-time (RT) GNSS meteorology can be further improved by incorporating observations from multiple Global Navigation Satellite System (GNSS), including GPS, GLONASS, Galileo, and BeiDou. In this paper, an operational RT system for extracting zenith troposphere delay (ZTD) using a modified version of the Precise Point Positioning With Integer and Zero-difference Ambiguity Resolution Demonstrator (PPP-WIZARD) was established. GNSS, including GPS, GLONASS, and Galileo, observation streams were processed using RT Precise Point Positioning (PPP) strategy based on RT satellite orbit/clock products from the Centre National d'Etudes Spatiales. An experiment covering 30 days was conducted, in which the observation streams of 20 globally distributed stations were processed. The initialization time and accuracy of the RT troposphere results using single-system and multisystem observations were evaluated. The effect of PPP ambiguity resolution was also evaluated. Results reveal that RT troposphere estimates based on single-system observations can both be applied in weather nowcasting, in which the GPS-only solution is better than the GLONASS-only solution. The performance can also be improved by PPP ambiguity resolution and utilizing GNSS observations. Specifically, we notice that ambiguity resolution is more effective in improving the accuracy of ZTD, whereas the initialization process can be better accelerated by GNSS observations. Combining all techniques, the RT troposphere results with an average accuracy of about 8 mm in ZTD can be achieved after an initialization process of approximately 8.5 min, which demonstrates superior results for applying GNSS observations and ambiguity resolution for RT meteorological applications. [less ▲]

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