GAGAN is a Satellite Based Augmentation System (SBAS) which is being developed by India. In Hindi, it means the sky. The Indian Space Research Organisation (ISRO) is jointly working with the Airports Authority of India (AAI) on this initiative.

The system has been developed on the basis of WAAS codes of US. The reference stations to this system will be located at Ahmedabad, Delhi, Guwahati, Jammu, Kolkata, Port Blair and Thiruvananthapuram with the master control at Bangalore. It will be integrated with the geostationary satellite GSAT-4 system.

GAGAN will be compatible with other SBAS systems such as the European Geostationary Navigation Overlay Service (EGNOS) and the Multi-functional Transport Satellite (MTSAT of Japan) augmentation system.

It will later be developed into an autonomous Indian Regional Navigational Satellite System (IRNSS). This will monitor weather and traffic movement of 100 aircrafts and 500 airports. Tests being carried out at New Delhi, Mumbai, Bangalore, Hyderabad and Kochi will soon be a requirement for the airport licensing process.

The data will provide fuel efficient routes, multiple approaches of aircrafts, autopilot-landing with a high positional accuracy of 1 meter, and airspace management in any weather conditions. By 2011 India is going to have the world’s most sophisticated satellite based air navigation system; benefiting both civilian and military aircraft.

With about 24 satellites devoted to GAGAN, it will cover areas up to central Africa, middle-east, Australia, eastern Europe and China.

Airspace Management Dept of Raytheon, US is providing it’s comprehensive expertise on development of GAGAN.