India’s homegrown GPS system NavIC to be operational next year
29 May 2017
India's homemade global positioning system, the Indian Regional Navigation Satellite System (IRNSS), alternatively named NavIC, is slated to be operational early next year.
The system is currently being tested for its accuracy and is most likely to be available in the market for public use early next year, reports quoting Isro sources said.
The testing involves ground verification and calibration of NavIC data so as to calculate its accuracy. Various academic institutions across the country are involved in the testing and calibration of data and once the system is fully operational, marketing will start.
India completed its indigenous global positioning network of seven satellites with the placing of the seventh GPS satellite in orbit last year.
The Indian system is expected to be significantly more accurate than the GPS powered by American satellites. The American GPS with 24 satellites in a constellation has wider reach and covers the entire world, while NavIC with seven satellites covers only India and its surroundings, but is more accurate than the American system.
The system is capable of providing terrestrial, aerial and marine navigation, including vehicle tracking and fleet management, disaster management, visual and voice navigation as also cater to the needs of defence forces
NavIC will cover the entire country, Indian Ocean and its surroundings, with a reach till eastern parts of Arabian peninsula in the west and up to some parts of China in the east. In the south, NavIC signals will work till Malaysia.
NavIC will provide standard positioning service to all users with a position accuracy of 5 metre. The GPS, on the other hand, has a position accuracy of 20-30 metres.
Unlike the GPS, NavIC system has dual frequency (S and L bands) allowing use of high and low frequency signals. GPS on the other hand, is dependent solely on L band and has to use atmospheric model to assess frequency error and update the model from time to time. This is because when low frequency signal travels through atmosphere, its velocity changes due to atmospheric disturbances.
In the case of the Indian system, it measures the difference in delay of dual frequency (S and L bands) in order to assess the actual delay. Therefore NavIC is not dependent on any model to find the frequency error and is more accurate than GPS.
India was forced to go for its own GPS system after the US refused to part with GPS information during the Kargil war, due to its own vested interests
With the NavIC system, India joins the select countries like the US, Russia, and the EU, to have this capability.
