But, Indians will be able to enjoy India’s own GPS by 2018. Thus, our dependence on American GPS will come to an end. Great.
“Though American GPS with 24 satellites in a constellation has wider reach and covers the entire world, NavIC with seven satellites covers only India and its surroundings but is 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 SAC director said.
Misra said, “Academic institutions have been roped in to do ground verification and calibrate data of NavIC to find its accuracy. We have developed digital chips to miniaturise technology (for use in mobiles and handsets) and experiments are on them. The system is being tested all across the country.” He said, “After the desi navigation system comes to market, big thing will be to popularise it (as American GPS dominates the navigation system market across the world).”
“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.” he added.