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GLONASS Ground Segment: Difference between revisions
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The SDCM orbit constellation will consist of three geostationary satellites from the multifunctional space relay system Luch (which means “ray” or “beam” in Russian). Luch 5A, to be launched in 2011 and positioned at 16°W longitude and Luch 5B, to be launched in 2012 and positioned at 95°E longitude, will transmit signals on an L1 frequency. Luch 4, to be launched in 2013 and positioned at 167°E longitude, will transmit on two frequencies. The three satellites will provide almost global coverage.<ref>[http://www.gpsworld.com/gnss-system/glonass/innovation-glonass-11405?page_id=4 GLONASS Augmentation Development, GPS World]</ref> | The SDCM orbit constellation will consist of three geostationary satellites from the multifunctional space relay system Luch (which means “ray” or “beam” in Russian). Luch 5A, to be launched in 2011 and positioned at 16°W longitude and Luch 5B, to be launched in 2012 and positioned at 95°E longitude, will transmit signals on an L1 frequency. Luch 4, to be launched in 2013 and positioned at 167°E longitude, will transmit on two frequencies. The three satellites will provide almost global coverage.<ref>[http://www.gpsworld.com/gnss-system/glonass/innovation-glonass-11405?page_id=4 GLONASS Augmentation Development, GPS World]</ref> | ||
The SDCM will make use of 12 monitor stations <ref>[http://www.oosa.unvienna.org/pdf/sap/2011/UAE/Presentations/04.pdf, Tatiana Mirgorodskaya]</ref> currently in operation in Russia and one in Antarctica at Russia’s Bellingshausen research station. Eight more monitor stations will be added in Russia and five more outside Russia (Cuba, Brazil, Vietnam, Australia, and Antarctica). | The SDCM will make use of 12 monitor stations <ref>[http://www.oosa.unvienna.org/pdf/sap/2011/UAE/Presentations/04.pdf, GLONASS Status, Performance and Modernization Efforts,Tatiana Mirgorodskaya]</ref> currently in operation in Russia and one in Antarctica at Russia’s Bellingshausen research station. Eight more monitor stations will be added in Russia and five more outside Russia (Cuba, Brazil, Vietnam, Australia, and Antarctica). | ||
SDCM will also provide service through the Internet. A system website (www.sdcm.ru) already gives users information about real-time and a posteriori GLONASS and GPS monitoring | SDCM will also provide service through the Internet. A system website (www.sdcm.ru) already gives users information about real-time and a posteriori GLONASS and GPS monitoring | ||
Revision as of 10:04, 16 June 2011
GLONASS | |
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Title | GLONASS Ground Segment |
Author(s) | GMV |
Level | Basic |
Year of Publication | 2011 |
The GLONASS Ground Segment (also referred to as Control Segment or Operational Control System) is the responsible for the proper operation of the GLONASS system.
The GLONASS Control Segment is composed by a network of Monitor Stations (MS), a Master Control Station (MCS), a backup of the MCS and the Ground Antennas (GA).
In order to ensure operation and coordination of the entire system, the GLONASS ground segment determines satellite orbits as well as time and frequency parameters regularly. In addition, the health of all satellites is monitored continuously.These corrections and the navigation message are uploaded to the satellites through the Ground Antennas, which are co-located in four of the Monitor stations (Ascension Island, Cape Canaveral, Diego Garcia, and Kwajalein).
Introduction
The ground segment consists of the System Control Center and the Central Synchronizer situated in Moscow. Seven additional ground stations are maintained in the territory of the former Soviet Union, serving for orbit determination and satellite monitoring. These stations are equipped with radar, laser distance meters and/or telemetry. They are situated near the following towns:[1]
- St. Petersburg TT&C
- Ternopol TT&C, laser ranging, monitoring
- Jenisejsk TT&C
- Komsomol’sk-na-Amure TT&C, laser ranging, monitoring
- Balchas Laser ranging
- Jevpatoria Laser ranging
- Kitab Laser ranging
System Control Centre (SCC)
The System Control Center (SCC) is responsible for satellite constellation control and management of GLONASS satellites. It provides the telemetry, telecommand and control function for the whole GLONASS satellite constellation. The SCC coordinates all functions and operations at the system level. It processes the information from the Command and Tracking stations to determine satellite clock and orbit states, and updates the navigation message for each satellite.
Command and Tracking Stations
The CTSs track the GLONASS satellites in view and accumulate ranging data and telemetry from the satellites signals. The information from CTSs is processed at the SCC to determine satellite clock and orbit states and to update the navigation message of each satellite. This updated information is transmitted to the satellites via the CTSs, which also used for transmitting of control information.
The Command and Tracking Stations are composed by a main network of four Telemetry, Tracking and Control (TT&C) stations distributed throughout the Russian territory (in St. Petersburg, Ternopol, Eniseisk and Komsomolsk-na- Amure).
The CTSs ranging data is periodically calibrated using a laser ranging devices at the Quantum Optical Tracking Stations which are within GCS. Each GLONASS satellite specially carries laser reflectors for this purpose. This network is complemented by other additional measurement stations (LS) in former Soviet Union territory (Balkhash in Kazakhstan, Evpatoria in Ukraine, Kitab in Uzbekistan), equipped with laser ranging and other monitoring facilities.
Central Synchroniser
The synchronization of all the processes in the GLONASS system is very important for its proper operability. There is the Central Synchronizer within GCS to meet this requirement. The Central Synchronizer is high-precise hydrogen atomic clock which forms the GLONASS system time scale. The onboard time scales (on a basis of satellite cesium atomic clocks) of all the GLONASS satellites are synchronized with the State Etalon UTC (CIS) in Mendeleevo, Moscow region, through the GLONASS System Time scale.
System of Differential Correction and Monitoring (SDCM)
Russia is advancing its plan to implement a GLONASS System of Differential Correction and Monitoring (SDCM) covering the Russian Federation. The SDCM would perform integrity monitoring of both GPS and GLONASS satellites as well as provide differential corrections and a posteriori analyses of GLONASS system performance.[2]
The SDCM orbit constellation will consist of three geostationary satellites from the multifunctional space relay system Luch (which means “ray” or “beam” in Russian). Luch 5A, to be launched in 2011 and positioned at 16°W longitude and Luch 5B, to be launched in 2012 and positioned at 95°E longitude, will transmit signals on an L1 frequency. Luch 4, to be launched in 2013 and positioned at 167°E longitude, will transmit on two frequencies. The three satellites will provide almost global coverage.[3]
The SDCM will make use of 12 monitor stations [4] currently in operation in Russia and one in Antarctica at Russia’s Bellingshausen research station. Eight more monitor stations will be added in Russia and five more outside Russia (Cuba, Brazil, Vietnam, Australia, and Antarctica). SDCM will also provide service through the Internet. A system website (www.sdcm.ru) already gives users information about real-time and a posteriori GLONASS and GPS monitoring