3. GLONASS
The Soviet union began development of
Glonass in 1976.
In 1982 a constellation of 24 satellites started
working properly.
After the collapse of Russia's economy ,
Glonass development was put on hold.
In 2001 the full satellite constellation was
finally restored on 2nd October by Russian
president VALDIMIR PUTIN.
5. How does GLONASS work?
System have 24 satellite constellations that orbit the
Earth at an altitude of 10,900 nautical miles.
These satellites broadcast their position and the
exact time that they are in that position on a
continuous basis. A glonass receiver compares the
signals from at least three or four satellites and sent
information towards the control segment.
Accuracy verification
• Russian system compares values, altitude, and
altitude rate estimates to US estimates for verification
and fault detection.
6. GLONASS SATELLITE
The Russian GLONASS consists of a constellation of 24 (21
active and 3 spares) satellites and their ground based
stations.
The satellites orbit the Earth once every 11hours and 15
minutes on three orbital planes separated by 120°.
Life expectancy of these satellites is 3-5 years. Next
generation satellites are being developed with an expected
service life of 10 years.
All ground based stations are located within former Soviet
Union territory.
In December 2010,three satellites crushed during launch.
8. Three segments of Glonass
Space segment
Ground/Cotrol segment
User segment
9. The main functions of the space segment are to transmit
radio navigation signal ,to store and transmits the
navigation message sent by the control segment.
The mechanism of high atomic clock.
The GLONASS space segment consist mainly of 24
operating satellite distributed over three orbital plane.
Each orbit consist of 8 satellites.
10. GLONASS Ground segment
The glonass ground segment or control segment is
responsible for the proper operation of glonass.
The glonass ground segment consist of:
_A system control centre located at KRASNOZNAMENSK.
_The central clock situated in SCHELKOVE near
MASCOW.
_Two laser ranging stations, a network of four monitoring
and measuring stations(Schelkove)
11. GLONASS user segment
The Glonass user segment consist on
receiver/processor and antennas which receive
glonass signals, determine pseudoranges and solve
the navigation in order to obtain their co-ordinates
and provide accurate time.
12. • The
time it takes for a signal to travel from the satellite to the
receiver gives a direct indication of distance. This distance from
the satellite is used by the receiver to fix position.
13. ERRORS
There are few other variables that the
receiver needs to take into account to
ensure accuracy:
Atmospheric error
Multipath error
Satellite geometry
14. GLONASS & GPS(NAVSTAR)
Both the system have their stregnths and
weaknesses while GPS is generally considered the
better option on most parts of the globe. Glonass is
believed to have a superior accuracy in the north
latitudes of the planet as the system was developed to
provide the best service to Russia which extends to
the highest latitudes.
15. Who can use GLONASS
As GPS Glonass was originally only for military.
The system was made available for public and
commercial use in 2007 although GPS has been
available for civilian use since 1990.
