GLONASS . Is a global positioning system and satellite navigation (Russian: ГЛОНАСС ; ГЛОбальная НАвигационная Спутниковая Система , pronounced: Globalnaya Navigatsionnaya Sputnikovaya System , literally satellite navigation ) consists of a constellation of 24 satellites (21 active and 3 in reserve ) located in three orbital planes with 8 satellites each and following an orbitinclined of 64.8º with a radius of 25,510 km. The constellation GLONASS orbits the earth with an altitude of 19,100 kilometers (lower than GPS) and each satellite takes approximately 11 hours and 15 minutes to complete one orbit. It represents the counterpart to the American GPS and the future European Galileo . The satellites have been launched from Tyuratam in Kazakhstan .
Summary
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- 1 History of the system.
- 2
- 3 generations of GLONASS satellites.
- 4 See also
- 5 Sources
History of the system.
Originally developed by the Soviet Union , the first three satellites were launched into orbit in October 1982 . It was expected to be ready for 1991 but due to economic problems caused by the fall of the USSR , it could not be finished. It was finally ready by December 1995 (a breakthrough that was not expected) and began operating on January 18 , 1996 . That same year, Russia offered the GLONASS Standard Accuracy Channel (CSA) to support the needs of the International Civil Aviation Organization.ICAO, and it accepted the offer. It is currently administered by the Russian Federation (Specifically by the Ministry of Defense of Russia)
In August 2001 , the government adopted a special long-term program called the “World Navigation System” for 10 years whose objectives were:
- Restore the orbital segment of the GLONASS system to 24 satellites for the period 2007 – 2008 .
- Modernize navigation satellites, with the second generation of satellites (GLONASS-M) with more features and a useful life that has been increased from 3 to 7 years, and incorporate the L2 signal in these satellites.
- For 2012 , gradually replacing the satellites with the third generation (GLONASS-K) with better performance and a useful life of 10 to 12 years, they will have the possibility of emitting the navigation signal on the L3 frequency (in addition to L1 and L2). by the aeronautical radionavigation band.
- Provide Search and Rescue (SAR) capabilities from GLONASS-KM in a similar way to the COSPAS-SARSAT system.
In 2004 , 11 satellites were operating. By December 2007 there were 19 operational satellites. 18 satellites are needed to serve the entire territory of Russia and 24 to be available the system worldwide. In 2007, Russia announced the removal of all precision restrictions (until that year for military use only) on GLONASS, thus allowing commercial and civil use of up to 30m of precision. The sale of receivers that allow the reception of signals from both systems, GLONASS and GPS, (with different reference systems) makes the possibilities of GLONASS in measurement as support for GPS more interesting and vice versa. In order to improve the accuracy, access, integrity and continuity of servicesof navigation for users of aviation .
Features.
Configuration and orbital elements of the system.
- Power source: 2 Solar Panels.
- Mass: between 1400 Kg. (Maximum Gen. GLONASS) and 700 Kg. (Gen. GLONASS-K).
- Diameter: 1294 cm. (1.29 m.)
- Equipment: 12 L-band antennas.
- Accuracy: 1 Cesium Atomic Clock.
- Matrices: Retroreflectors.
- Stabilization: on 3 axes.
- Orbit type: Circular.
- Eccentricity: between 0.0001 and 0.0035
- Inclination: between 64.2 and 65.6 degrees.
- Orbital period: 676 minutes.
- Periaster: Approx. 19,000 to 19,100 km
GLONASS satellite generations.
- First generation satellites: GLONASS, they were the first to orbit, they had a useful life of 3 to 5 years. With a stabilized 3-axis configuration, plus retroreflectors. They were powered by 2 solar panels, with a mass of 1400 Kg in total weight. They had multiple radio frequency L-band antennas and a 1 Cesium atomic clock .
- Second generation satellites: GLONASS-M, incorporate the L2 civil signal (improving the accuracy and reliability of navigation and improves immunity against interference in the receiver for civil use), has radio links between satellites to carry out online control of the system integrity and increase the uptime of the constellation of satellites without loss of navigation accuracy.
- Third-generation satellites: GLONASS-K incorporate considerably better size- mass parameters . The L3 signal (since 2008), will have frequency division in the channels and a bandwidth of 26 MHz in the 1189-1215 MHz band. Its weight does not exceed 700 kg. and it will allow launching these satellites using the Proton launch rocket with up to 6 satellites in one launch, allowing the orbital segment to be reestablished in a short time and the Soyuz launch rocket , with 2 satellites in one launch. This would allow to maintain the orbital segment in the future. These capabilities allowed the deployment and maintenance costs of the GLONASS orbital segment to be reduced several times.
The program also plans to carry out scientific research and experimental design tasks to develop a new generation of satellites and finally modernize the GLONASS Ground Control Complex and start the production of versatile commercial equipment and a monitoring system of the technical state of the orbital segment. (satellites).
