ISRO’s IRNSS-1G navigation satellite: Interesting facts about India’s own GPS

India on 28th April 2016 completed its landmark mission for a regional navigational system on par with US-based GPS with the successful launch of IRNSS-1G, the seventh and last in the constellation of satellites that make up the system. When the IRNSS-1G becomes operational in about a month’s time, the Indian Regional Navigation Satellite System (IRNSS) would offer services like terrestrial and marine navigation, disaster management, vehicle tracking and fleet management, navigation aide for hikers and travellers, visual and voice navigation for drivers.

The Indian Space Research Organization (ISRO) launched the seventh rocket from Sriharikota in Andhra Pradesh, and it was successfully placed in orbit. With this launch, India does not have to depend on another nation for military navigation.

The main purpose of the IRNSS is to deliver indigenously developed accurate GPS service to Indian users as well as for the defense purposes. According to ISRO, the IRNSS will serve two types of services – SPS (Standard Positioning Service) and a RS (Restricted Service). The SPS will be available for all users in the country whereas the RS will be an encrypted services for authorized users, which most probably will be used for defence purposes.

Here are interesting points that you need to know about the IRNSS:

The satellite IRNSS-1G (Indian Regional Navigation Satellite System-1G) is part of a constellation of seven satellites to provide accurate position information service to users across the country and the region, extending up to an area of 1,500 km.

Till date, India has launched six regional navigational satellites (IRNSS-1A, 1B, 1C, ID, 1E and 1F). Though the full system comprises nine satellites — seven in orbit and two on the ground as stand-by, the navigation services could be made operational with four satellites, ISRO officials said earlier.

Each satellite costs about Rs.150 crore while the PSLV-XL version rocket costs about Rs.130 crore. The seven rockets would entail an outlay of about Rs.910 crore. The first satellite, IRNSS-1A, was launched in July 2013, the second in April 2014, the third on October 2014, the fourth in March 2015, and the fifth and sixth on January 20 and March 10 this year. Once the regional navigation system is in place, India does not need to depend upon other platforms.

The IRNSS is similar to the global positioning system (GPS) of the US (24 satellites), Glonass of Russia, and Galileo of Europe as well as China’s Beidou. While GPS and Glonass are fully functional global systems, the Chinese and the Japanese systems are offering regional coverage and Europe’s Galileo is yet to be operational.

The IRNSS will provide two types of services — standard positioning service and restricted service. The former is provided to all users and the latter is an encrypted service for authorised users.