The radio payload on every NavIC satellite that broadcasts timing and orbit signals, from which a receiver on the ground works out its position.
Each NavIC satellite constantly broadcasts its exact time and its position in orbit. A receiver picks up signals from several satellites, compares the arrival times, and works out where it is. The payload's signals are timed by a rubidium atomic clock.
NavIC offers a Standard Positioning Service to everyone and an encrypted Restricted Service for authorised users. It is designed to give a position accuracy better than 20 m over India and up to 1,500 km beyond its borders.
The first-generation satellites, IRNSS-1A to 1I, transmit in two bands: L5 and S. Using two frequencies lets a receiver correct for delays as the signal passes through the ionosphere. The second-generation NVS satellites add a third band, L1, the band most other navigation systems also use, which makes NavIC easier to combine with them for civilian users.
Each satellite also carries a separate C-band ranging transponder, used by ground stations to measure the satellite's distance precisely, and laser retroreflectors.
PSLV launched IRNSS-1A to 1G between July 2013 and April 2016, and IRNSS-1I in April 2018. IRNSS-1H was lost in 2017 when the rocket's heat shield failed to separate. NVS-01 (2023) began the second generation. NVS-02, launched in January 2025, could not raise its orbit after reaching transfer orbit.