What do you do when you are dependent on a global power, and it ditches you when you need it the most? You decide to become self-reliant. That's what India set out to do two decades ago, and is now on the verge of accomplishment.When Pakistani troops took positions in Kargil in 1999, one of the first things Indian military sought was global positioning system (GPS) data for the region. The space-based navigation system maintained by the US government would have provided vital information, but the US denied it to India. A need for an indigenous satellite navigation system was felt earlier, but the Kargil experience made the nation realise its inevitability.Two decades later, NavIC, India's own GPS which has been developed to challenge the current GPS system of the West, is in the final stages of launch. It will soon be offered as an Indian counter to foreign systems currently being used by companies and others.“Request for Proposal (RFP) has been called to start the implementation of NavIC so that the platform can be rolled out and popularised,” IT secretary Ajay Prakash Sawhney told TOI.The GPS was named NavIC ('Navigation with Indian Constellation' whose Hindi meaning is 'sailor' or 'navigator'), by Prime Minister Narendra Modi after the launch of Indian Regional Navigation Satellite System (IRNSS) 1G, the last of the seven dedicated satellites, in 2016.NavIC is designed to provide accurate position information to users within the country. It will help India enter the club of select countries which have their own positioning systems. Besides America’s GPS (with 24 satellites in a constellation), Russia has its GLONASS and European Union its Galileo. Interestingly, China is also in the process of building Beidou Navigation Satellite System.With seven satellites, the NavIC covers only India and its surroundings and is considered to be more accurate than the American system. NavIC will provide standard positioning service to all users with a position accuracy of 5 metre. The GPS, on the other hand, has a position accuracy of 20-30 metre. The indigenous navigation system is believed to have cost Isro around Rs 1,400 crore, and 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.Even more remarkable for Indian scientists is that NavIC is technically superior to the American GPS. "Our system has dual frequency (S and L bands). GPS is dependent only on L band. When low frequency signal travels through atmosphere, its velocity changes due to atmospheric disturbances. US banks on atmospheric model to assess frequency error and it 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. Therefore NavIC is not dependent on any model to find the frequency error and is more accurate than GPS," Tapan Misra, the director of Ahmedabad-based Space Application Centre (SAC), told ET last year.