Indian Regional Navigation Satellite System (IRNSS) – NavIC

• IRNSS is an independent regional navigation satellite system developed by the Indian Space Research Organization (ISRO).
• In April 2016, with the last launch of the constellation’s satellite, IRNSS was renamed Navigation Indian Constellation (NAVIC).

Range of NavIC

• It is designed to provide accurate position information service to users in India as well as the region extending up to 1500 km from its boundary, which is its primary service area.
• Beyond that lies an Extended Service Area, that can extend up to the edges of the area enclosed by the rectangle imagined by latitudes 30 degrees South and 50 degrees North, and longitudes 30 degrees East and 130 degrees East.
• IRNSS will provide two types of services, namely, Standard Positioning Service (SPS) which is provided to all the users and Restricted Service (RS), which is an encrypted service provided only to the authorised users.
• The IRNSS System is expected to provide a position accuracy of better than 20 m in the primary service area.
• The space segment consists of the IRNSS constellation of eight satellites (with one being a replacement). Three satellites are located in the geostationary orbit and the remaining four are located in geosynchronous orbits.

Applications 

• Applications of IRNSS include:
  • Terrestrial, Aerial and Marine Navigation
  • Disaster Management
  • Vehicle tracking and fleet management
  • Integration with mobile phones
  • Precise Timing
  • Mapping and Geodetic data capture
  • Terrestrial navigation aid for hikers and travellers
  • Visual and voice navigation for drivers

Why in News?

• Union Minister of State Science & Technology Dr Jitendra Singh said that 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.
• NavIC can help in navigation on land, air, sea and also in disaster management.
• 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.

Related Information

Geostationary vs Geosynchronous orbits

Geosynchronous Orbit

• The orbit around the Earth with an orbit period equal to one sidereal day (i.e. 23 Hrs, 56 minutes, 4 seconds) is known as geosynchronous orbit. The word “synchronous” means an object in this orbit returns to the same position after a period of 1 sidereal day to the observer on the Earth’s surface.
• There are many such orbits around the Earth. It may be circular or non-circular types.
• Geosynchronous satellites have an inclination with respect to the equator.

Geostationary Orbit

• The circular orbit at an altitude of 35768 Kms above the equator of the Earth which follows the direction of rotation of the Earth is known as geostationary orbit.
• Object in this orbit has a period equal to the rotation period of the earth. Hence it appears motionless from earth or at fixed position to observers on the ground w.r.t. his/her position. Hence the word “stationary”.
• There is only one such orbit around the Earth.
• It is one type of Geosynchronous orbit. It is a circular orbit.
• Geostationary satellites have zero inclination with respect to the equator.

Reference:

1. https://pib.gov.in/PressReleasePage.aspx?PRID=1848313