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GLONASS Performances: Difference between revisions

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* operational control and ground monitoring segment limited to Russian territory.
* operational control and ground monitoring segment limited to Russian territory.


The improvements carried out on the space, ground-based and user equipment segments have paid off, increasing the accuracy of GLONASS by 5 times in the last years<ref name="Modernization_Revnivykh">[http://www.navcen.uscg.gov/pdf/cgsicMeetings/50/%5B3%5DCGSIC_GLONASS_Revnivykh_20_09_2010.pdf GLONASS Status and Progress, Sergey Revnivykh]</ref> and providing 100% availability in the Russia territorry and practically global coverage.
The improvements carried out on the space, ground-based and user equipment segments have paid off, increasing five times the accuracy of GLONASS in the last years<ref name="Modernization_Revnivykh">[http://www.navcen.uscg.gov/pdf/cgsicMeetings/50/%5B3%5DCGSIC_GLONASS_Revnivykh_20_09_2010.pdf GLONASS Status and Progress, Sergey Revnivykh]</ref> and providing 100% availability in the Russia territorry and practically global coverage.


==GLONASS Availability==
==GLONASS Availability==

Revision as of 13:21, 7 July 2011


GLONASSGLONASS
Title GLONASS Performances
Author(s) GMV
Level Basic
Year of Publication 2011
Logo GMV.png


One of the main objectives of the Global Navigation System (GNS) is to ensure GLONASS performance similar to GPS by the end of 2011. GLONASS traditional poorer performance was the culmination of several factors:[1]

  • poorer on-board atomic clocks
  • less stability and predictability in the satellite orbits (and therefore less accuracy in GLONASS broadcast ephemerides)
  • fewer satellites providing signals
  • operational control and ground monitoring segment limited to Russian territory.

The improvements carried out on the space, ground-based and user equipment segments have paid off, increasing five times the accuracy of GLONASS in the last years[2] and providing 100% availability in the Russia territorry and practically global coverage.

GLONASS Availability

Integral availability of GLONASS navigation (PDOP≤6) during the 24 hours period (mask angle ≥5 deg) Date: 25.04.2011

At the moment of this publication (April 2011) there are 27 GLONASS satellites in orbit although only 23 of them are operational. Availability performance (calculated as the percentage of time during which the condition PDOP ≤ 6 is valid at mask angles ≥ 5 deg) obtained with the current constellation is shown in the right figure.

Date Operational Satellites in constellation Integral Availability Global Integral Availability on Russian territory
2011/07/06 23 99.5 % 100 %
2011/01/01 22 99 % 100 %
2010/01/01 15 73.6 % 85.3 %
2009/01/01 16 87.4 % 96.6 %
2008/01/01 12 48 % 57.6 %
2007/01/01 9 19.2 % 26.3 %

GLONASS accuracy

According to Revnivykh,[2] deputy director of the Russian space agency’s Mission Control Cente, GLONASS accuracy has five times improved in the last years. As it is shown in the figure on the right, in 2006 GLONASS Signal In Space Range Error (SISRE) at 1 sigma was in the order of 25 m. At the moment of this publication, July 2011, the accuracy of GLONASS is 6-7 metres, the same order as GPS.

As Anatoly Shilov said at the 5th international forum on satellite navigation yesterday, the accuracy of the Russian navigation system would have to be improved to 2-3 metres in the following years.

Notes

References