How Does IRNSS Help in Navigation?

IRNSS satellites continuously emit microwave radiation. The microwave signals contain information about the position of satellites and precise time from atomic clocks. The signals from at least four satellites are received by ground receivers, which then triangulate their own position using the position of satellites and the time taken for the signals to reach the receiver. Out of the four satellites, three are used for calculating the position in space (latitude, longitude, and altitude) and the fourth one is for timing correction. These receivers, if integrated with maps, can be used for turn-by-turn navigation guidance as is the case with Google maps.

Indian Regional Navigation Satellite System (IRNSS), with the operational name NavIC (Navigation with Indian Constellation), is a system of 7 satellites, 3 in geostationary orbit and 4 in geosynchronous orbit. This is a satellite navigation system, like GPS, that provides positioning and timing services with very high accuracy in real-time. The need for developing a homegrown GPS has arisen due to the geostrategic and military importance of such a system, though most of its use will be in the civilian domain. 

Satellite navigation has its origin in the “Space Race” of the Cold War era between the United States of America (USA) and the Soviet Union (USSR). The USA started experimenting with satellite navigation in the 1960s by tracking their own nuclear submarines using the phenomenon of the “Doppler Effect”. The project gained prominence in the mid-70s and the USA was able to perfect the Global Positioning System (GPS) by the year 1993 with the launch of the 24th satellite of the system, which allowed complete global coverage at all times. 

Though GPS has been considered a reliable navigation system, it has been alleged that the USA can deny the service to a particular area or feed wrong coordinates to an enemy nation. It was reported that during the Iraq war, the Iraqi military was fed wrong coordinates of the location of the USA army, and hence all the attacks against America were rendered ineffective. Again, it has been alleged that the USA denied the military-grade GPS signals to India during Kargil War. This may become a major problem in the long run if countries controlling the satellite navigation systems refuse to help India in hostile and critical situations.  

With this thought in mind, India embarked on the journey of creating its own homegrown Indian Regional Navigation Satellite System (IRNSS). 

It has a coverage area of up to 1500 km beyond the territorial boundaries of India. Like USA-operated GPS, IRNSS also provides service at two levels – the “standard positioning service” (open to civilian use) and a restricted use (for defense services and other authorized agencies).