1. What is IRNSS?
  2. 7 Satellites of IRNSS
  3. IRNSS-C launch
  4. Benefits of IRNSS Desi-GPS system?
  5. Why waste money building Desi GPS?
  6. GAGAN
  7. Appendix1: IRNSS-Scientific principle
  8. Appendix 2: Russian GLONASS

What is IRNSS?

  • Indian Regional Navigation Satellite System (IRNSS).
  • 2006: Government approved project with ~Rs.1500 crores.
  • American Global positioning system has 24 orbiting satellites, a global network of ground stations. Thus GPS covers every part of the world.
  • But, given this small budget, it is beyond ISRO’s aukaat to maintain 24 satellites to cover entire globe,
  • Therefore, our Desi GPS will use just seven satellites, and try to cover India + 1,500 km beyond its borders.
  • HQ: ISRO Navigation Centre at Byalalu, near Bangalore. It’ll control this system.

IRNSS Indian regional navigation satellite system

7 Satellites of IRNSS
3 satellites
  • These three of the satellites will be placed over the equator, in the geostationary orbit.
  • they match the Earth’s rotation and therefore appear from the ground to remain at a fixed position in the sky.
+4 satellites
  • will be in pairs in two inclined geosynchronous orbits.
  • From the ground, these satellites will appear to travel in figures of ‘8’ during the course of a day.
  • All seven IRNSS satellites will be at a height of about 36,000 km, taking a whole day to circle the Earth.
  • In future, we can add more satellites to increase coverage surrounding India. and with God willing, one day 25-30 satellites to cover entire earth, just like American-GPS.

So far 3 out 7 satellites launched

When Jul. 2013 April 2014 Oct. 2014
Where Satish Dawan Space Centre in Sriharikota, Andhra
Using PSLV* C22 C24 C26

*PSLV: Polar Satellite Launch vehicle.

IRNSS-C launch

(Mains-GS3) Q.Write a shortnote on the importance of IRNSS-C satellite launch  100 words.

WHEN? October 2014. Hence the need for publishing this stupid article.
WHERE? Satish Dawan Space Centre in Sriharikota.
HOW? using Polar Satellite Launch Vehicle (PSLV C26)
  • Carried two payloads
  • A: Device to send navigation signal to users
  • B: C-band transponders to help in laser ranging. (to help Military / artillery range estimation)

In next two years, remaining satellites will be launch, and Desi-GPS system will become operational.

Benefits of IRNSS Desi-GPS system?

(Mains-GS3) Discuss the benefits of IRNSS system 200 words.

Two services IRNSS will offer two services:

  • Standard Positioning Service: that will be accessible to anyone
  • Restricted Service: Will be available only to the military and other government-authorized users.
Accuracy American GPS: 15 metersOur IRNSS: 20 meters.
  • The standard GPS receiver (in your smartphones and tablets) will not work with IRNSS.
  • You’ll need a special receiver equipment to use navigation data from
  • Will serve both civil and military users.
  • Will provide time-location coordinates on land, sea and air.
  • Cell phone apps- for mapping, driving, hiking in jungle and remote areas. And if you use it with Idea-internet then rickshaw-walla can’t make you ‘ullu’.
  • Forest department: Putting out wildfire, tracking endangered animals.
  • Fleet Management e.g. taxi or truck company can monitor whether their driver is on right path or not.
  • Disaster Management.
  • During war: naval fleet Management, missile navigation etc.

Why waste money building Desi GPS?

Interview question: Why should Indian Government waste money on IRNSS? Why not simply use American GPS at a fraction of that cost?

IRNSS vs American GPS

At present only three countries have fully functional global navigation systems. (EU’s Galileo system yet to become fully operational)

Russia GLONASS (more under appendix)
China Beidou
  • To deploy a global navigation system, you need to setup lots of satellites hovering around the world, so they can scan and sent pinpoint location of anywhere to anywhere.
  • During the Iraq war, the Americans sent wrong GPS signals to the Iraqi jets and missiles, therefore Iraqis could not attack Americans forces in a precise manner.
  • Moral of the story = Don’t rely on other people’s navigation system.
  • For the short term, We (India) have designed our missiles and fighter jets to can use both GPS (American) and GLONASS (Russian) signals for navigation.
    • So if we want to attack America or its ally Pakistan, we can rely on GLONASS
    • And if we want to attack Russia or its ally China, we can rely on American GPS.
  • But for long term, we will need our own Desi-GPS system.
  • Same reason why we need Anti-satellite missiles, to shoot down videsi-GPS systems during war.


(Mains-GS3) Write a short note on GAGAN system. 100 words

  • ‘Global Positioning System Aided Geo Augmented Navigation System (GAGAN) for civil aviation purposes.
  • GPS aided geo augmented navigation’ (gagan)
  • It is a joint effort by the ISRO and the Airports Authority Of India (AAI).
  • It’s main use is to help Air traffic control and helps pilots fly / land aircrafts in bad weather.
  • But as the name suggests “GPS aided …” meaning it is not a separate independent navigation system.
  • It depends on GPS (American navigation system). Therefore we need IRNSS for long term solution.

Appendix1: IRNSS-Scientific principle

Since IRNSS project will still take two years to complete= Topic remains important for scientific principle MCQs in CSAT prelim 2015, 2016 and even 2017 (because even in 2017, Hindu will keep doing “mahimaa-gaan” every once in a while). So, let’s finish the scientific principle once and for all.

Microwaves: how they help in GPSing?

  • IRNSS satellites use two microwave frequency bands: L5 and S.
  • These microwaves travel at speed of light.
  • Your receiver (the GPS-like gadget) will calculate the delay between microwave’s transmission and its reception = thus you get coordinates on earth.

Atomic Clocks

  • For above microwave-calculation, Navigation satellites have to periodically transmit their precise position in orbit with exact time.
  • For this, we can’t fit Timex or Sonata watches in the satellite. They need to carry extremely accurate clocks with long shelf-life.
  • Therefore, Each IRNSS satellite is equipped with rubidium atomic clocks, to keep precise time.

Appendix2: Russian GLONASS

This is an old topic from 2012. Dead horse resurrects because of IRSNSS.

MCQs relevance: similarities and differences between American GPS, GLONASS and IRNSS.

  • Glonass is Russia’s Global Navigation Satellite System.
  • It provides location and time information anywhere in the planet.
  • Glonass is an alternative to the U.S.-controlled Global Positioning System (GPS).
  • 2012: Mohan-Putin signed agreement for use of GLONASS.
  • GLONASS navigation system will allow Indian missiles, to strike within half a metre of distant targets= very accurate.
  • GLONASS is fitted on Nuclear submarine Chakra= killer combo.
Civilian use
  • iPhone 4S mobile supports both GPS and GLONASS.
  • You can use it to know distance covered during jogging etc.
  • Finding shortest possible route during travel
Commercial use
  • Keep track of your school-buses, transport trucks etc.