Hummingbird News Desk
NEW DELHI, 4 AUG: India’s satellite-based navigation system, NavIC, is as good as GPS of the United States in terms of position accuracy and availability in its service region. Replying to a question in the Rajya Sabha, Union Science and Technology Minister Dr Jitendra Singh said today.
According to Dr Singh, NavIC can help in navigation on land, air, sea and also in disaster management. NavIC satellites are placed at a higher orbit than the GPS of United States. NavIC satellites are placed in geostationary orbit (GEO) & geosynchronous orbit (GSO) with an altitude of about 36,000 km; GPS satellites are placed in medium earth orbit (MEO) with an altitude of about 20,000 km.
He said NavIC uses dual frequency bands, which improves accuracy of dual frequency receivers by enabling them to correct atmospheric errors through simultaneous use of two frequencies. It also helps in better reliability and availability because the signal from either frequency can serve the positioning requirement equally well.
At the time of inception, an indigenously developed satellite navigation system was conceptualized to cater to requirements of critical national applications, including those of defence and commercial establishments. Hence the coverage area was designed to cover Indian Territory and surrounding 1500 km of Indian borders. The needs of critical national applications do evolve with time and efforts are continuously made to meet these requirements, including from the point of view of coverage.
NavIC 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 US denied the Indian request for Global Positioning System (GPS) data for the Kargil region.
NavIC, an acronym of the ‘Navigation with Indian Constellation) is an autonomous regional satellite navigation system that provides India with real-time positioning and timing services. NAVIC is the operational name of the Indian Regional National Satellite System (IRNSS), cover India and an area of 1500 kilometres around it, and is under discussion for further expansion. Currently, NAVIC has seven satellite constellations and two satellites on the ground that are kept on stand-by. It would provide two levels of service, ‘the standard positioning service’ that would be open for civilian use. Still, the local service would only be for authorised users, for instance, the military.
The Global Positioning System monitors the entire globe and is monitored by the United States of America. The system needs nearly 24 operational satellites and has 31 satellites in orbit. All the 55 satellites are geosynchronous satellites, which means that they do not remain stationary in space regarding the revolving earth. Moreover, the GPS uses a single frequency which is more complex.
On the other hand, India’s NavIC has four geosynchronous and three geostationary satellites. Since all these satellites are placed in a higher orbit, there are lesser chances of obstruction. Compared to the GPS, the NavIC used two frequency bands, the L5 band and the S-Band, making the system more accurate and reliable. The accuracy rate of NavIC compared to that of GPS, because of which it might not show a drastic improvement. However, the location accuracy of NavIC might see a drastic improvement in urban locations where geolocation accuracy tends to degrade.
Tags: #NavIC #GPS #SatelliteBasedNavigation #India #JitendraSingh #GEO #GSO
