CHENNAI,Jan23,2012: Flights over the country and the Indian Ocean, from East Africa to Australia, will soon be safer, more economical and environment friendly with the Airports Authority of India (AAI) moving a step closer to installing a GPS-aided geo-augmented navigation system (Gagan) for commercial aircraft. Once the system is operational, by late 2013 or early 2014, it will plug a hole in the global satellite-based aircraft navigation umbrella over a vast expanse through which aircraft had to fly with navigational coordinates and no real time geo-positioning. The Rs 800 crore project, taken up by AAI, Indian Space Research Organisation (Isro) and Raytheon, will take India into an exclusive club whose members possess the advanced system including the US, Japan and Europe. "Fifteen reference and ground stations including one at Port Blair have been established and networked using high performance communication circuits. Signals from the satellite are being used to test for availability of standbys and other features of the network," said D Devaraj, southern regional executive director, AAI. Standby testing, or redundancy testing in aviation parlance, is crucial because at least three ground locations will be required to position an aircraft and at least two ground locations will be used to route an aircraft when it is in Indian airspace. "We are now waiting for Isro to launch its next geo satellite, which is expected in March this year, to take the next step in setting up the system," he added. Isro is scheduled to launch GSAT-10 spacecraft that will carry 12 C Band and 12 Extended C Band transponders and a second Gagan payload after subsystem fabrication and testing are completed. A third satellite with another Gagan payload, for back up functions, will be launched sometime next year. Gagan's geosatellites will use the C band, normally used for long-distance telecommunication, and the L band, also used by EU's Galileo satellite navigation system. Gagan will help aircraft take the shortest possible routes, saving fuel and time, with GPS data provided by the satellites. Aircraft will not need to depend on ground-based navigational aids like VOR (VHF omni directional range) or NDB (non-directional beacon). Air routes are currently based on the availability of ground-basednavigational units. Multiple satellites and ground stations will track an aircraft's speed, altitude, position and route and cross check for accuracy. Gagan comprises of three geo stationary satellites, 15 reference stations, two master control stations and three uplink stations.
