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Know all about navigation – The world of GNSS

You know where you are, but do you know where you have to go?

What’s the solution? Navigation

Through?  Global Network Satellite System or GNSS provides the location and time information anywhere on the earth

Use of satellites for navigation began with the US Navy Navigation Satellite System, NNSS in 1964

The need to have an independent military capability drove this growth and now it’s for civilian use as well

GNSS have increased rapidly into four major global and two regional systems.


Global Positioning System (United States)

Popularly known as GPS

The oldest system began operations in 1978

It has 31 operational satellites in its constellation

Committed to maintain the availability of at least 24 operational GPS satellites

It is maintained by the US Air Force

GLONASS (Russia)

Became operational in 1993 over Russia with 12 satellites in 2 orbits at 19,130 km

Total satellites in constellations 27, all operational

Operated by the Russian Aerospace Defence Forces

Second alternative navigational system in operation


Galileo (EU)

14 Satellites are in orbit


4 More to be launched in November 2016

The fully deployed Galileo system will consist of 24 operational satellites plus 6 in-orbit spares

Created by the European Union through the European Space Agency and the European GNSS Agency

Galileo has started offering Early Operational Capability from 2016

It will go to Initial Operational Capability in 2017-18 and reach Full Operational Capability in 2019


BeiDou (China)

21 Operational satellites, full constellation is scheduled to comprise 35 satellites

First BeiDou system, called the BeiDou Satellite Navigation Experimental System consisted of 3 satellites

The second generation is of 35-satellite constellation known as BeiDou-2

Became operational in December 2011, with 10 satellites

Began offering services to customers in the Asia-Pacific region in December 2012

The third generation BeiDou system BDS-3 was launched in 2015 and is a global coverage constellation

As of March 2016, total of 4 BDS-3 in-orbit validation satellites have been launched


QZSS (Japan)

Total 4 satellites planned; 1 in orbit

Full operational status expected by 2018

Work under taken by the Satellite Positioning Research and Application Center, Japan



7 Satellite constellations, all operational

3 Satellites are in the geostationary orbit and 4 in geosynchronous orbits

Designed to provide accurate position information service to users in India

But it can cover the region extending up to 1,500 km from its boundary

Created and operated by Indian Space Research Organisation

But there is still some time before India starts getting its services