scholarly journals ANALYSIS OF POSITIONING DEVIATION BETWEEN BEIDOU AND GPS BASED ON NATIONAL REFERENCE STATIONS IN CHINA

Author(s):  
M. Chen ◽  
Q. Zhang

Abstract. In order to probe into the characteristics of positioning deviation between Beidou Navigation Satellite System (Beidou) and global positioning system (GPS), and investigate possible contribution of Beidou data to refinement of global coordinate system, refined calculation is made on observation data of 240 national reference stations that are distributed uniformly across China on the whole in this study. These stations support satellite signals of four global navigation satellite systems, including Beidou, GPS, GLONASS and Galileo, and a 5-year time span from 2016 to 2020 is adopted. In this study, PPP is calculated based on GPS data and Beidou single system data in no-difference resolution network mode, and accurate coordinates of national reference stations in two processing modes are obtained. Analysis of difference between the calculations based on Beidou data and on GPS data shows that the consistency between Beidou and GPS positioning results reaches about 5 mm in the east and in the north, and about 1.3 cm in the height direction.

2020 ◽  
pp. 1-21 ◽  
Author(s):  
Jian Chen ◽  
Xingwang Zhao ◽  
Chao Liu ◽  
Shaolin Zhu ◽  
Zhiqiang Liu ◽  
...  

The single initial Global Positioning System (GPS) has been expanded into multiple global and regional navigation satellite systems (multi-GNSS/RNSS) as the Global Navigation Satellite System (GLONASS) is restored and the BeiDou Navigation Satellite System (BDS), Galileo Satellite Navigation System (Galileo) and Quasi-Zenith Satellite System (QZSS) evolve. Using the differences among these five systems, the paper constructs a consolidated multi-GNSS/RNSS precise point positioning (PPP) observation model. A large number of datasets from Multi-GNSS Experiment (MGEX) stations are employed to evaluate the PPP performance of multi-GNSS/RNSS. The paper draws three main conclusions based on the experimental results. (1) The combined GPS/GLONASS/Galileo/BDS/QZSS presents the PPP with the shortest mean convergence time of 11·5 min, followed by that of GPS/GLONASS/Galileo/BDS (12·4 min). (2) The combined GPS/GLONASS/BDS/Galileo/QZSS shows the optimal PPP performance when the cut-off elevation angle is basically the same because of the rich observation data due to a large number of satellites. To be specific, for combined GPS/GLONASS/BDS/Galileo/QZSS, the PPP convergence percentage is 80·9% higher relative to other combined systems under 35° cut-off elevation angle, and the percentages of the root mean square values of PPP within 0–5 cm are enhanced by 80·5%, 81·5% and 87·3% in the North, East and Up directions relative to GPS alone at 35° cut-off elevation angle. (3) GPS alone fails to conduct continuous positioning due to the insufficiency of visible satellites at 40° cut-off elevation angle, while the kinematic PPP of multi-GNSS/RNSS remains capable of obtaining positioning solutions with relatively high accuracy, especially in the horizontal direction.


2007 ◽  
Vol 42 (3) ◽  
pp. 149-153
Author(s):  
A. Farah

Code Single Point Positioning Using Nominal Gnss Constellations (Future Perception) Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning from different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, Glonass and Galileo) using different combinations. This study presents results of code single point positioning for five stations using the three constellations and different combinations.


2020 ◽  
Vol 6 (3) ◽  
pp. 115-123
Author(s):  
Ivan Korobtsev ◽  
Tatyana Tsukker ◽  
Marina Mishina ◽  
Vladimir Goryashin ◽  
Maxim Eselevich

The problem of the amount and characteristics of space debris in the vicinity of orbits of Global Navigation Satellite Systems (GNSS) is of significant interest from the viewpoint of safe operation of these systems. Attempts have repeatedly been made to search for space debris fragments in a given region of orbits, but have not led to cataloging such objects. Only in 2018, eight space objects were discovered which were not related to active or inactive spacecraft or their launch elements. Photometrical and trajectory observations with optical telescopes are practically the only source of information about characteristics of such objects. The paper presents a summary of the design features and technical characteristics of the new AZT-33VM telescope. We describe a technique for determining orbital parameters of non-cataloged space debris from optical measurements. We report the results of photometric observations of a space object, detected in the vicinity of orbits of the Global Navigation Satellite System GLONASS.


2021 ◽  
Vol 13 (18) ◽  
pp. 3698
Author(s):  
Haomeng Cui ◽  
Shoujian Zhang

Positioning accuracy is affected by the combined effect of user range errors and the geometric distribution of satellites. Dilution of precision (DOP) is defined as the geometric strength of visible satellites. DOP is calculated based on the satellite broadcast or precise ephemerides. However, because the modernization program of next-generation navigation satellite systems is still under construction, there is a lack of real ephemerides to assess the performance of next-generation constellations. Without requiring real ephemerides, we describe a method to estimate satellite visibility and DOP. The improvement of four next-generation Global Navigation Satellite Systems (four-GNSS-NG), compared to the navigation constellations that are currently in operation (four-GNSS), is statistically analyzed. The augmentation of the full constellation the Quasi-Zenith Satellite System (7-QZSS) and the Navigation with Indian Constellation (11-NavIC) for regional users and the low Earth orbit (LEO) constellation enhancing four-GNSS performance are also analyzed based on this method. The results indicate that the average number visible satellites of the four-GNSS-NG will reach 44.86, and the average geometry DOP (GDOP) will be 1.19, which is an improvement of 17.3% and 7.8%, respectively. With the augmentation of the 120-satellite mixed-orbit LEO constellation, the multi-GNSS visible satellites will increase by 5 to 8 at all latitudes, while the GDOP will be reduced by 6.2% on average. Adding 7-QZSS and 11-NavIC to the four-GNSS-NG, 37.51 to 71.58 satellites are available on global scales. The average position DOP (PDOP), horizontal DOP (HDOP), vertical DOP (VDOP), and time DOP (TDOP) are reduced to 0.82, 0.46, 0.67 and 0.44, respectively.


2008 ◽  
Vol 43 (2) ◽  
pp. 65-73
Author(s):  
A. Farah

Double-Difference Carrier-Phase Network Solution Using Nominal Gnss Constellations (Future Perception)Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning accuracy using different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, Glonass and Galileo) using different combinations. This study presents results of double-difference carrier-phase solution for five stations-network using the three constellations and different combinations.


2020 ◽  
Author(s):  
Qisheng Wang ◽  
Shuanggen Jin ◽  
Youjian Hu

Abstract. The differential code bias (DCB) of global navigation satellite systems (GNSS) is an important error source in ionospheric modeling, which was generally estimated as constants every day. However, the receiver DCB may be changing due to the varying space environments and temperatures. In this paper, the receiver DCB of BeiDou Navigation Satellite System (BDS) is estimated as the changing parameter within one day with epoch-by-epoch. The BDS receiver DCBs are analyzed from 30 days of multi-GNSS experiment observations. The comparison of estimated receiver DCB of BDS with the DCB provided by German Aerospace Center (DLR) and Chinese Academy of Sciences (CAS) shows a good agreement. The root mean square (RMS) values of receiver DCB are 0.43 and 0.80 ns with respect to DLR and CAS, respectively. In terms of the intra-day variability of receiver DCB, most of the receiver DCBs show relative stability within one day with the intra-day standard deviation (STD) of less than 1 ns. However, larger fluctuations with more than 2 ns of intra-day receiver DCB are found. Besides, the intra-day stability of receiver DCB calculated by the third-generation BDS (BDS-3) and the second-generation BDS (BDS-2) observations is compared. The result shows that the intra-day stability of BDS-3 receiver DCB is better than that of BDS-2 receiver DCB.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2396
Author(s):  
Qingsong Ai ◽  
Kamil Maciuk ◽  
Paulina Lewinska ◽  
Lukasz Borowski

This research is focused on searching for frequency and noise characteristics for available GNSS (Global Navigation Satellite Systems). The authors illustrated frequency stability and noise characteristics for a selected set of data from four different GNSS systems. For this purpose, 30-s-interval clock corrections were used for the GPS weeks 1982–2034 (the entirety of 2018). Firstly, phase data (raw clock corrections) were preprocessed for shifts and removal of outliers; GLONASS and GPS satellites characterize a smaller number of outliers than BeiDou and Galileo clock products. Secondly, frequency and Hadamard deviation were calculated. This study concludes that the stability of GPS and Galileo is better than that of BDS (BeiDou Navigation Satellite System) and GLONASS. Regarding noise, the GPS, Galileo, and BDS clocks are affected by the random walk modulation noise (RWFM), flashing frequency modulation noise (FFM), and white frequency modulation noise (WFM), whereas the GLONASS clocks are mainly affected only by WFM.


2020 ◽  
Vol 6 (3) ◽  
pp. 94-100
Author(s):  
Ivan Korobtsev ◽  
Tatyana Tsukker ◽  
Marina Mishina ◽  
Vladimir Goryashin ◽  
Maxim Eselevich

The problem of the amount and characteristics of space debris in the vicinity of orbits of Global Navigation Satellite Systems (GNSS) is of significant interest from the viewpoint of safe operation of these systems. Attempts have repeatedly been made to search for space debris fragments in a given region of orbits, but have not led to cataloging such objects. Only in 2018, eight space objects were discovered which were not related to active or inactive spacecraft or their launch elements. Photometrical and trajectory observations with optical telescopes are practically the only source of information about characteristics of such objects. The paper presents a summary of the design features and technical characteristics of the new AZT-33VM telescope. We describe a technique for determining orbital parameters of non-cataloged space debris from optical measurements. We report the results of photometric observations of a space object, detected in the vicinity of orbits of the Global Navigation Satellite System GLONASS.


2021 ◽  
Vol 5 (1) ◽  
pp. 44-50
Author(s):  
N. V. Leonidov

The purpose of this article is to analyze the existing algorithms of autonomous control of the integrity of the navigation field of the GLONASS system. The analysis is based on domestic materials and official foreign applications. At the beginning of the article, the concept of the integrity of the global navigation satellite system is given in the form in which it is used in International Civil Aviation Organization and among the developers of such systems. The differences between the common types of control of the integrity of the navigation field are shown. The modeling of individual operational characteristics, including the average geometric factor, visibility, and accessibility for different angles of the site, is carried out. The main solutions to the problem of reduced tactical and technical characteristics of the system are compared. The existing prerequisites for the improvement of the GLONASS system and for the use of small navigation spacecraft to eliminate the gap between GLONASS and competing global navigation satellite systems are listed. As a result, a variant of improving the circumstances for the application of these algorithms in unfavorable conditions in relation to the GLONASS system is proposed. It is shown that the low-orbit addition to the GLONASS system can significantly improve the tactical and technical characteristics of the complex as a whole and provide higher reliability of the system as a whole due to the operational maintenance of the integrity of the navigation field.


Indian Regional Navigation Satellite System (IRNSS) is India’s own navigation system. It is a seven satellite constellation with the operational name NavIC – Navigation with Indian Constellation. Satellite Orbit determination (OD) estimates the position and velocity of orbiting satellite. The two main estimation algorithms widely used in Global Navigation Satellite Systems (GNSS) are Extended Kalman Filter (EKF) and Least Squares. This study on Batch Least Squares (BLS) - Differential Correction (DC) algorithm demonstrates precise orbit estimation of any GEO missions using only range measurements with crude initial state parameters. Currently, the study is based on simulated inputs and the satellite orbits are successfully estimated with position error in sub-centimeters level. Further, the work will be extended to live data of IRNSS satellites.


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