New Delhi, July 14 2015: The Indian Minister of Civil Aviation, P. Ashok Gajapathi Raju, formally launched the GAGAN system (GPS AIDED GEO AUGMENTED NAVIGATION) at a function here yesterday.
GAGAN is the first SBAS (Satellite Based Augmentation System) in the world certified for Approach with Vertical Guidance operating in the Equatorial Ionospheric region and the third SBAS to have achieved this feat, after WAAS of USA and EGNOS of Europe. GAGAN was already certified for en route operation since 30th December 2013.
GAGAN is a joint effort of Airport Authority of India (AAI) and Indian Space Research Organization (ISRO). In the aviation field, GAGAN will support more direct air routes, reduce fuel consumption and improve safety. In addition, GAGAN provides benefits to agriculture, all modes of transportation and public services such a defence services, security agencies and disaster recovery management by aiding in search and rescue to locate the disaster zone accurately.
Since February 14 2014, GAGAN has been continuously providing navigation signals from GSAT-8 and GSAT-10 satellites launched by ISRO, augmenting the performance of GPS signals received over Indian Airspace.
How GAGAN works
The Global Navigation Satellite System (GNSS) data is received and processed at widely dispersed INRES which are strategically located to provide coverage over the required service volume. Data is forwarded to the INMCC, which process the data from multiple INRES to determine the differential corrections and residual errors for each monitored satellite and for each predetermined ionospheric grid point (IGP). Information from the INMCC is sent to the INLUS and uplinked along with the GEO navigation message to the GAGAN GEO satellite. The GAGAN GEO satellite downlinks this data to the users via two L-band ranging signal frequencies (L1 and L5), with GPS type modulation, to improve the accuracy and availability and provide integrity.
Seamless Coverage: GAGAN will provide augmentation service for GPS over India, Bay of Bengal, South-East Asia, Middle East expanding upto Africa. GAGAN will be compatible and interoperable with other SBAS systems such as the Wide Area Augmentation System (WAAS) of USA, the European Geostationary Navigation Overlay Service (EGNOS) of European Union (EU) and the Multi-functional Satellite Augmentation System (MSAS) of Japan. It will fill the gap between the European EGNOS and the Japanese MSAS to provide seamless air navigation service across regional boundaries.