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 orbit64.8º inclined with a radius of 25 510 km. The GLONASS constellation orbits the Earth at an altitude of 19,100 km (lower than GPS), and it takes approximately 11 hours and 15 minutes for each satellite to complete an orbit. It represents the counterpart to the American GPS and the future European Galileo . Satellites have been launched from Tyuratam , in Kazakhstan .
[ hide ]
- 1 History of the system.
- 2 Features.
- 3 generations of GLONASS satellites.
- 4 See also
- 5 Sources
Initially 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 completed. It was finally ready for December 1995 (an advance 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 ICAO accepted the offer. It is currently administered by the Russian Federation (Specifically by the Russian Ministry of Defense)
In August 2001 , the government adopted a special long-term program called “Global Navigation System” for 10 years whose objectives were:
- Reset the GLONASS system orbital segment 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 raised from 3 to 7 years, and incorporate the L2 signal in these satellites.
- By 2012, gradually replace 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 similar to the COSPAS-SARSAT system.
In 2004 , 11 satellites were operating. As of December 2007, there were 19 operational satellites. 18 satellites are required to serve the entire territory of Russia and 24 to make the system available worldwide. In 2007, Russia announced the removal of all precision restrictions (until that year for military use only) on the GLONASS, thus allowing commercial and civil use of up to 30m precision. The sale of receivers that allow receiving signals from the two systems, GLONASS and GPS, (with different reference systems) makes the possibilities of GLONASS more interesting in measurement as support for GPS and vice versa. In order to improve the precision, access, integrity and continuity of servicesof navigation for users of aviation .
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: in 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, were the first in orbit, had a useful life of 3 to 5 years. With a stabilized 3-axis configuration, plus retroreflectors. They were powered by the energy of 2 solar panels, with a mass of 1400 Kg of total weight. They had multiple radio frequencyL-band antennas and a 1 Cesium atomic clock .
- Second generation satellites: GLONASS-M, incorporating the civil L2 signal (improving the accuracy and reliability of navigation and improving immunity against interferencein the receiver for civil use), it has radio links between satellites to perform online control of the integrity of the system and increase the operating time of the satellite constellation without loss of navigation accuracy.
- Third generation satellites: GLONASS-K incorporate considerably better size- massparameters . The L3 signal (from 2008) will have a 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 restored in a short time and the Soyuz launch rocket , with 2 satellites in one launch. This would allow the orbital segment to be maintained in the future. These capabilities reduced the deployment and maintenance costs of the GLONASS system’s orbital segment 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 production of versatile commercial equipment and a monitoring system for the technical status of the orbital segment. (satellites).