Augmentation of global navigation satellite systems (GNSSs) had helped nations worldwide across sectors and more so in aviation. India is implementing Geo Augmented GPS Aided Navigation (GAGAN) to ensure air-space accuracy, reliability, availability and safety, making it the fourth country to implement a Satellite Based Augmentation System (SBAS). The US, Europe, Japan have already implemented it.
GAGAN has been jointly developed by the Airports Authority of India (AAI) and Indian Space Research Organization (ISRO). It comprises a constellation of three geostationary satellites (namely GSAT 8, 10 and 15), three Master Control Centres (two in Bengaluru and one in Delhi), three Uplink Stations and 15 Reference Stations spread across India.
The primary purpose of GAGAN is to enhance the accuracy of the GPS signals and improve its availability, integrity and continuity across India and neighbouring countries. GAGAN is claimed to be the first SBAS in the world certified for approach with vertical guidance operating in the equatorial ionosphere region.
Source: Defence Aviation post