Aircraft equipped with the Satellite Based Augmentation System (SBAS) will henceforth be able to use GPS-Aided Geo Augmented Navigation (GAGAN) signal in Indian airspace for en route navigation and non-precision approaches without vertical guidance.
The commencement of a new chapter in the aviation sector of the country comes in the wake of the Director General of Civil Aviation (DGCA) certifying the GAGAN system to RNP0.1 (Required Navigation Performance 0.1 Nautical Mile) service level.
The SBAS consists of 15 Indian Reference Stations, three Indian Navigation Land Uplink Stations, three Mission Control Centres, three Geo-Stationary Navigation Payload in C and L bands and with all the associated software and communication links.
Mission control centres, along with associated uplink stations, have been set up at Kundalahalli in Bangalore. Another control centre and uplink station are in Delhi. A top official of the AAI said one of the Reference Stations has been housed outside the premises of the Thiruvananthapuram airport. The reference stations pick up signals from the orbiting GPS satellites. The measurements are immediately passed on to the mission control centres that then work out the necessary corrections that must be made. Messages carrying those corrections are sent via the uplink stations to the satellites in geostationary orbit that have the GAGAN payload.
Establishing position The satellites then broadcast the messages. The SBAS receivers use those messages and apply the requisite corrections to the GPS signals, thereby establishing their position with considerable accuracy.
The GAGAN system is poised to next level of certification in the near future to offer precision approach services to the aircraft.
Jointly developed by the Indian Space Research Organisation (ISRO) and the Airports Authority of India (AAI), the GAGAN system will offer seamless navigation to the aviation industry. The ISRO has confirmed that the DGCA certification was received on December 30 last.
With this, the country has become the fourth to offer safety of life, space-based satellite navigation services to the aviation sector. GAGAN will provide augmentation service for GPS over the country, Bay of Bengal, South East Asia and Middle East expanding up to Africa.
The availability of the GAGAN signal in the country’s air space will bridge the gap between European Union’s European Geostationary Navigation Overlay Service (EGNOS) and Japan’s Multi-functional Satellite Augmentation System (MSAS) coverage areas.
The benefits of GAGAN include improved efficiency, direct routes, increased fuel savings, approach with vertical guidance at runways, significant cost savings due to withdrawal of ground aids and reduced workload of flight crew and Air Traffic Controllers.