Indian Regional Navigation Satellite System
The Indian Regional Navigation Satellite System (IRNSS), with an operational name of NavIC (acronym for Navigation with Indian Constellation; also, nāvik 'sailor' or 'navigator' in Indian languages),[2] is an autonomous regional satellite navigation system that provides accurate real-time positioning and timing services.[3] It covers India and a region extending 1,500 km (930 mi) around it, with plans for further extension up to 3,000 km (1,900 mi).[4] An extended service area lies between the primary service area and a rectangle area enclosed by the 30th parallel south to the 50th parallel north and the 30th meridian east to the 130th meridian east, 1,500–6,000 km (930–3,730 mi) beyond borders where some of the NavIC satellites are visible but the position is not always computable with assured accuracy.[5] The system currently consists of a constellation of eight [6] satellites,[7][8] with two additional satellites on ground as stand-by.[9]
Country/ies of origin
Military, Commercial
Operational
Regional (up to 1,500 km or 930 mi from borders)
3 m or 9.8 ft (public)
2 m or 6 ft 7 in (encrypted)
5
1 July 2013
29 May 2023
10
geostationary orbit (GEO), inclined geosynchronous orbit (IGSO)
35,786 km (22,236 mi)
The constellation is in orbit as of 2018.[10][11][12][13] NavIC will provide two levels of service, the "standard positioning service", which will be open for civilian use, and a "restricted service" (an encrypted one) for authorised users (including the military).
NavIC-based trackers are compulsory on commercial vehicles in India[14][15] and some consumer mobile phones with support for it have been available since the first half of 2020.[16][17][18][19][20]
There are plans to expand the NavIC system by increasing its constellation size from 7 to 11.[21]
Background[edit]
The system was developed partly because access to foreign government-controlled global navigation satellite systems is not guaranteed in hostile situations, as happened to the Indian military in 1999 when the United States denied an Indian request for Global Positioning System (GPS) data for the Kargil region, which would have provided vital information.[22] The Indian government approved the project in May 2006.[23]
Time-frame[edit]
In April 2010, it was reported that India plans to start launching satellites by the end of 2011, at a rate of one satellite every six months. This would have made NavIC functional by 2015. But the program was delayed,[35] and India also launched 3 new satellites to supplement this.[36]
Seven satellites with the prefix "IRNSS-1" will constitute the space segment of the IRNSS. IRNSS-1A, the first of the seven satellites, was launched on 1 July 2013.[37][38] IRNSS-1B was launched on 4 April 2014 on-board PSLV-C24 rocket. The satellite has been placed in geosynchronous orbit.[39] IRNSS-1C was launched on 16 October 2014,[40] IRNSS-1D on 28 March 2015,[41] IRNSS-1E on 20 January 2016,[42] IRNSS-1F on 10 March 2016 and IRNSS-1G was launched on 28 April 2016.[43]
The eighth satellite, IRNSS-1H, which was meant to replace IRNSS-1A, failed to deploy on 31 August 2017 as the heat shields failed to separate from the 4th stage of the rocket.[44] IRNSS-1I was launched on 12 April 2018 to replace it.[45][46]