What is Navigation with Indian Constellation?

The 29-hour countdown for the launch of India's eighth navigation satellite Indian Regional Navigation Satellite System (IRNSS-1H) began at 2 pm on Wednesday at the Sriharikota rocket port. The 1,425-kg satellite will be carried by Polar Satellite Launch Vehicle (PSLV) rocket XL variant that will blast off on Thursday evening at around 7 p.m., said the Indian Space Research Organisation (ISRO).

Simiply put, the IRNSS or NavIC (Navigation with Indian Constellation) is similar to the US-owned GPS. The Rs 1,420-crore Indian satellite navigation system NavIC consists of nine satellites -- seven in orbit and two as substitutes. One of the substitutes is the IRNSS-1H.

IRNSS is an independent regional navigation satellite system being developed by India. 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.

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. Some applications of IRNSS are: 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; and Visual and voice navigation for drivers.

According to ISRO, NavIC is useful for fishermen to reach the potential fishing area. The fishermen can also get alert messages relating to bad weather, high waves or when they approach international maritime boundary line. These services are provided through a software application on a smart phone. NavIC helps merchant ships in their navigation and also during search and rescue operations.

In the road transport sector, NavIC helps commuters to traverse distances and also enable transport operators to track their vehicles. It is useful for railways in tracking trains and also giving an alert in the case of unmanned level crossing. NavIC is also used for other applications like location-based services, survey and alignment, time synchronised services.