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Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou.

Li X, Zhang X, Ren X, Fritsche M, Wickert J, Schuh H - Sci Rep (2015)

Bottom Line: At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years.This will bring great opportunities and challenges for both scientific and engineering applications.The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, 430079, Wuhan, Hubei, China [2] German Research Centre for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, Germany.

ABSTRACT
The world of satellite navigation is undergoing dramatic changes with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs). At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years. This will bring great opportunities and challenges for both scientific and engineering applications. In this paper we develop a four-system positioning model to make full use of all available observations from different GNSSs. The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.

No MeSH data available.


The code and phase residuals of several typical satellites from different navigation satellite systems and orbital types [G02 (GPS), R04 (GLONASS), C02 (BeiDou GEO), C06 (BeiDou IGSO), C14 (BeiDou MEO), and E20 (Galileo)], on September 3, 2013 (GPS Time).
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f14: The code and phase residuals of several typical satellites from different navigation satellite systems and orbital types [G02 (GPS), R04 (GLONASS), C02 (BeiDou GEO), C06 (BeiDou IGSO), C14 (BeiDou MEO), and E20 (Galileo)], on September 3, 2013 (GPS Time).

Mentions: Observation residuals, which mainly contain the observation noises, multipath, and other errors that are not fully modeled, can also be used as an important index to assess the observation quality and positioning accuracy. Figure 14 shows the phase and code residuals of several typical satellites from different satellite systems and orbital types. It can be seen that the phase residuals are generally within ±2.0 cm and the code residuals are generally within ±3.0 m, except some low-elevation periods. The large errors of the code observations will not influence the positioning results significantly as the weighting of code observations is much smaller (usually about 1:10,000) than that of phase observations. Figure 15 shows the RMS values of the phase and code residuals for different satellite systems and orbital types. The RMS value of GPS code residuals is about 1.6 m. The RMS value of GLONASS code residuals is about 1.3 m and smaller compared to GPS. This conclusion is different from the findings in some other publications, e.g., Cai and Gao (2013)10. These authors found that the GLONASS residuals are much larger compared to GPS. It can be explained by the fact that the GLONASS inter-frequency biases are well considered in our multi-system positioning model. In addition, the inter-frequency bias parameters can also absorb the systematic part of code errors to some extent. The RMS value of Galileo code residuals is smallest and about 1.2 m, while the RMS value of BeiDou MEO's code residuals is largest and about 1.7 m. For the different orbital types of BeiDou satellites, the RMS of GEO residuals is smallest and about 1.3 m, while the RMS of the IGSO residuals is about 1.5 m, which is between that of GEO and MEO. It is similar to the situation of MPCs and the possible reason is that the proportion of low-elevation periods for IGSO is lower than that of MEO and the GEO satellites have the lowest low-elevation proportion as their stable elevations within service regions. For the BeiDou phase observations, the RMS of the GEO residuals is also smallest and about 0.9 cm, while the RMS of MEO residuals is also largest and about 1.4 cm. We can also find that the RMS value of BeiDou MEO residuals is even slightly smaller than GPS residuals, which is about 1.7 cm. The GLONASS residuals are slightly larger than GPS ones and the corresponding RMS is about 1.9 cm. The Galileo residuals have the largest RMS of 2.5 cm, which can be caused by some modeling parameters that are not accurate enough (e.g. phase center offset and variation values).


Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou.

Li X, Zhang X, Ren X, Fritsche M, Wickert J, Schuh H - Sci Rep (2015)

The code and phase residuals of several typical satellites from different navigation satellite systems and orbital types [G02 (GPS), R04 (GLONASS), C02 (BeiDou GEO), C06 (BeiDou IGSO), C14 (BeiDou MEO), and E20 (Galileo)], on September 3, 2013 (GPS Time).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321187&req=5

f14: The code and phase residuals of several typical satellites from different navigation satellite systems and orbital types [G02 (GPS), R04 (GLONASS), C02 (BeiDou GEO), C06 (BeiDou IGSO), C14 (BeiDou MEO), and E20 (Galileo)], on September 3, 2013 (GPS Time).
Mentions: Observation residuals, which mainly contain the observation noises, multipath, and other errors that are not fully modeled, can also be used as an important index to assess the observation quality and positioning accuracy. Figure 14 shows the phase and code residuals of several typical satellites from different satellite systems and orbital types. It can be seen that the phase residuals are generally within ±2.0 cm and the code residuals are generally within ±3.0 m, except some low-elevation periods. The large errors of the code observations will not influence the positioning results significantly as the weighting of code observations is much smaller (usually about 1:10,000) than that of phase observations. Figure 15 shows the RMS values of the phase and code residuals for different satellite systems and orbital types. The RMS value of GPS code residuals is about 1.6 m. The RMS value of GLONASS code residuals is about 1.3 m and smaller compared to GPS. This conclusion is different from the findings in some other publications, e.g., Cai and Gao (2013)10. These authors found that the GLONASS residuals are much larger compared to GPS. It can be explained by the fact that the GLONASS inter-frequency biases are well considered in our multi-system positioning model. In addition, the inter-frequency bias parameters can also absorb the systematic part of code errors to some extent. The RMS value of Galileo code residuals is smallest and about 1.2 m, while the RMS value of BeiDou MEO's code residuals is largest and about 1.7 m. For the different orbital types of BeiDou satellites, the RMS of GEO residuals is smallest and about 1.3 m, while the RMS of the IGSO residuals is about 1.5 m, which is between that of GEO and MEO. It is similar to the situation of MPCs and the possible reason is that the proportion of low-elevation periods for IGSO is lower than that of MEO and the GEO satellites have the lowest low-elevation proportion as their stable elevations within service regions. For the BeiDou phase observations, the RMS of the GEO residuals is also smallest and about 0.9 cm, while the RMS of MEO residuals is also largest and about 1.4 cm. We can also find that the RMS value of BeiDou MEO residuals is even slightly smaller than GPS residuals, which is about 1.7 cm. The GLONASS residuals are slightly larger than GPS ones and the corresponding RMS is about 1.9 cm. The Galileo residuals have the largest RMS of 2.5 cm, which can be caused by some modeling parameters that are not accurate enough (e.g. phase center offset and variation values).

Bottom Line: At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years.This will bring great opportunities and challenges for both scientific and engineering applications.The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, 430079, Wuhan, Hubei, China [2] German Research Centre for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, Germany.

ABSTRACT
The world of satellite navigation is undergoing dramatic changes with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs). At the moment more than 70 satellites are already in view, and about 120 satellites will be available once all four systems (BeiDou + Galileo + GLONASS + GPS) are fully deployed in the next few years. This will bring great opportunities and challenges for both scientific and engineering applications. In this paper we develop a four-system positioning model to make full use of all available observations from different GNSSs. The significant improvement of satellite visibility, spatial geometry, dilution of precision, convergence, accuracy, continuity and reliability that a combining utilization of multi-GNSS brings to precise positioning are carefully analyzed and evaluated, especially in constrained environments.

No MeSH data available.