Indian Regional Navigation Satellite System IRNSS

RELEVANCE – UPSC GS PRELIMS & GS MAINS – III

First go through the text (given after the questions) and then attempt the questions.

UPSC QUESTIONS

UPSC 2018

QUES .  With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements :

1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
2. IRNSS covers entire India and about 5500 sq. km beyond its borders.
3. India will have its own satellite navigation system with full global coverage by the middle of 2019.

Which of the statements given above is/are correct ?

(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) None

Answer. a

PRACTICE QUESTIONS

QUES .   At present IRNSS consists of –

a . IRNSS-1B , IRNSS-1C , IRNSS-1D ,  IRNSS-1E , IRNSS-1F , IRNSS-1G and  IRNSS-1I.

b . IRNSS-1A ,  IRNSS-1B , IRNSS-1C , IRNSS-1D ,  IRNSS-1E , IRNSS-1F and IRNSS-1G.

c . IRNSS-1A ,  IRNSS-1B , IRNSS-1C , IRNSS-1D ,  IRNSS-1E , IRNSS-1F and IRNSS-1I

d . IRNSS-1A , IRNSS-1I , IRNSS-1B , IRNSS-1C , IRNSS-1D ,  IRNSS-1E and IRNSS-1F 

Answer – a

ABOUT  IRNSS

The Indian Regional Navigation Satellite System (IRNSS) with an operational name of NAVIC (NAVigation with Indian Constellation) is an autonomous regional satellite navigation system, that provides accurate real-time positioning and timing services.

It covers India and a region extending 1,500 km  around it. The system at present consists of a constellation of seven satellites, with two additional satellites on ground as stand-by.

The constellation is already in orbit and system was expected to be operational from early 2018 after a system check.

IRNSS_Auto0

Objective of the project

The objective of the project is to implement an independent and indigenous regional space borne navigation system for national applications.

Services provided by NAVIC

NAVIC will provide two levels of service, the “standard positioning service” will be open for civilian use, and a “restricted service” (an encrypted one) for authorized users (including military).

Applications of IRNSS

IRNSS applications include

1 . Terrestrial, aerial and marine navigation;
2 . Disaster management
3 .  Vehicle tracking and fleet management
4 .  Precise timing mapping and geodetic data capture
5 .  Terrestrial navigation aid for hikers and travellers
6 .  Visual and voice navigation for drivers

Satellites under IRNSS and their launch 

IRNSS-1A, the first of the seven satellites, was launched on 1 July 2013. IRNSS-1B was launched on 4 April 2014 on-board PSLV-C24 rocket. The satellite has been placed in geosynchronous orbit. IRNSS-1C was launched on 16 October 2014, IRNSS-1D on 28 March 2015, IRNSS-1E on 20 January 2016,IRNSS-1F on 10 March 2016 and IRNSS-1G was launched on 28 April 2016.

However atomic clocks of IRNSS-1A failed in 2017. But ISRO’s attempt to replace IRNSS-1A with IRNSS-1H was unsuccessful when PSLV-C39 mission failed on 31 August 2017. After that a  replacement satellite, IRNSS-1I, was successfully placed into orbit on 12 April 2018.

Thus at present IRNSS consists of –  IRNSS-1B , IRNSS-1C , IRNSS-1D ,  IRNSS-1E , IRNSS-1F , IRNSS-1G and  IRNSS-1I.

Orbits of the satellites

Three of the seven satellites are located in geostationary orbit (GEO) approximately 36,000 km  above earth surface. Remaining four satellites are in inclined geosynchronous orbit (GSO). The four GSO satellites will appear to be moving in the form of an “8”.

How IRNSS is better than GPS?

GPS has 31 satellites, while IRNSS has only 7 satellites then  how will we get an accurate location from IRNSS?

24 functional satellites of GPS is for the entire globe, while 7 satellites of IRNSS is covering only India and its neighboring countries.

While GPS is using only L-Band signals, NavIC is using both L AND S Band. Since our signals are coming vertically from stationary reference, our NavIC is going to work better than GPS in crowded places. If you use both L and S bands, our accuracy is more than 5 meters. This has a better potential than a 20-meter accuracy GPS.

Above all IRNSS will free India from foreign dependency as access to foreign government-controlled global navigation satellite systems is not guaranteed in hostile situations, as happened to the Indian military in 1999 when it was dependent on the American Global Positioning System (GPS) during the Kargil War.