It was a small group of Indian scientists who helped prevent the detection of test sites from orbiting satellites of many countries done by a mind-boggling exercise of calculating and tracking their movements, visibility while organising the groundwork at Pokhran to stay undetected even in the open deserts of Rajasthan.
A year later, when Pakistani troops positioned themselves in Kargil in 1999, the Indian military sought GPS data for the region. The navigation system would have provided vital information but the United States flatly denied it to India. This made the nation realise the need to have its own home-grown indigenous satellite navigation system.
Underlining India’s dependence, in 2012, the US shut off its GPS satellites causing the BrahMos missile tests to fail. The GPS system couldn’t link on-board computers with hovering satellites eventually crippling its guidance system and stalled it from achieving mission objectives.
And then, on July 1, 2013 India launched IRNSS-1A - the first satellite in the Indian Regional Navigation Satellite System (IRNSS) followed by a series of satellites over the next six years till finally IRNSS-1I launched on 12 April 2018 completing the constellation of seven functional satellites to provide foolproof satellite-based navigation signals. But the journey towards its success was far from smooth.
It was following the successful launch of navigation satellite IRNSS-1G that Prime Minister Narendra Modi named the new system ‘NavIC’ (boatman) dedicating it to the people of the country and said SAARC countries can also take advantage of its services. PM Modi expanded 'NavIC' as 'Navigation with Indian Constellation'.
After the launch of IRNSS-1G on 28 April 2016, India attained the pride position to be among the world's five countries which have their own GPS system and navigation system, said the PM.
The system held the promise of the nation’s reduction in dependence on US Global Positioning System. Apart from India only the US, the European Union, China and Russia had their own navigation systems in place.
But things weren’t as smooth for India. After all, India’s journey has always been associated with hitches that underlined the ISRO resolve and determination. Three atomic clocks on-board INRSS-1A and used for precise coordination and to account for the effects of general relativity, failed.
To replace the failed IRNSS-1A and complete the constellation of seven satellites was launched IRNSS-1H on 31 August 2017. Sadly, ISRO’s eighth navigation satellite IRNSS-1H, India’s first satellite built by private sector and supervised by ISRO, failed too. The heat shield could not be separated and the satellite did not complete the 4th stage.
True to its repute, ISRO pooled in its resources and launched, within eight months of the failure of IRNSS-1H, its latest IRNSS-1I on 12 April 2018 in a ‘textbook launch’ to replace the faulty IRNSS-1A completing the NavIC constellation of seven satellites.
The 1,425-kg satellite was made by Bengaluru-based Alpha Design Technologies in collaboration with ISRO and is the second satellite to be actively built by the private industry.
There are three ‘Global Navigation Satellite Systems (GNSS)’ in the world. GPS (Global Positioning System) of United States, GLONASS (Global Satellite Navigation System) of Russia, Galileo of European Union and Compass/BeiDou-2 of China. There are two ‘Regional Satellite Navigation Systems’, the QZSS (Quasi-Zenith Satellite System) of Japan and Compass of China.
NavIC, built indigenously, will aid terrestrial, aerial and marine navigation, vehicle tracking and fleet management, disaster management, mapping and geodetic data capture, visual and voice navigation for drivers. Also capable of being integrated with mobile phones, NavIC is all set to be the perfect navigation tool for hikers and travellers across India. A restricted service providing enhanced access will be used by the military for missile delivery and navigation and tracking of aircraft.
NavIC covers only India, the Indian Ocean and its surroundings and is considered to be more accurate than the American system. It will provide standard positioning service to all users with a position accuracy of five metre. The GPS, on the other hand, has a position accuracy of 20 metre-30 metres.
India’s NavIC uses dual frequency (S and L bands) while the US-based GPS is dependent only on L band. When low frequency signal travels through atmosphere, its velocity changes due to atmospheric disturbances. US depends on an atmospheric model to assess frequency error and has to update this model from time to time to assess the exact error. In India’s case, we measure the difference in delay of dual frequency (S and L bands) and can assess the actual delay. NavIC, therefore, is not dependent on any model to find the frequency error and is more accurate than GPS.
With NavIC is being built an ongoing GPS Aided Geo Augmented Navigation (GAGAN) project as a Satellite Based Augmentation System (SBAS) for the Indian Airspace. And then, if that isn’t ambitious enough, India has also initiated processes for GINS or the Global Indian Navigation System which, when it happens, catapult the nation onto an all-powerful platform on par with the best in the world. The statutory filing for frequency spectrum of GINS satellite orbits, which projects India's requirement in a specific international space, has already been done.
India has arrived and is all set to rule, even in space - the final frontier!
A version of this article first appeared here.