Will GAGAN navigation system be a game-changer for Indian aviation?

The Airports Authority of India successfully conducted a light trial using the GAGAN satellite navigation system for the landing of an ATR72 aircraft belonging to IndiGo at the Kishangarh Airport in Rajasthan last week. 

GAGAN is a system jointly developed by the Airports Authority of India and the Indian Space Research Organisation (ISRO) in collaboration with US defence contractor Raytheon at an estimated cost of Rs 774 crores.

It provides a very accurate and high-level of satellite signals for precision air navigation over the entire Indian airspace, with the capability of expanding to nearby regions. It is capable of providing navigation services for departure, en-route and landing operations to equipped planes.

The DGCA had issued a mandate, directing that all aircraft registered in India after July 1st 2021 to be fitted with GAGAN equipment. 

Simply speaking, GAGAN is a Satellite Based Augmentation System or SBAS, which is a regional network of ground stations and satellites that provide GPS signal corrections, giving a better position accuracy. 

GPS is the most prevalent Global Navigation Satellite System (GNSS) and is owned by the US government. GAGAN is the fourth such SBAS system that has been operationalised after the US’ WAAS, European Union’s EGNOS an d Japan’s MSAS and it is interoperable with the other three. 

The GAGAN system consists of 15 earth-based reference stations, two master control centres, three land uplink stations and three geostationary satellites.

The reference stations gather GPS satellite data and the master control centres collect data from reference stations and create GPS correction messages. 

Through this, errors caused by ionospheric disturbances, satellite orbit errors and inaccurate clocks are corrected. And through the uplink stations, the corrected messages are sent to the geostationary satellites which then broadcast them to the aircraft.  

India is the first country in the Asia Pacific Region to trial indigenous SBAS for landing. 

According to SV Satish, former executive director (Air Traffic Management), AAI, GAGAN opens a gateway for all airports to have low visibility approaches. It will bring down diversions, save fuel and boost efficiency. He says, GAGAN can serve smaller airports effectively, and older aircraft have to be upgraded with GAGAN receivers. 

GAGAN will help airports which are currently devoid of precision approach capability equipment and have higher visibility requirements. It will reduce flight delays, save fuel, and improve flight safety.

Now, aircraft will be able to land at airports not equipped with expensive Instrument Landing Systems, which include many small regional airports. 

At present, IndiGo, SpiceJet, Air India, Go First and AirAsia India have aircraft that are capable of carrying out these satellite-based procedures.

As GAGAN’s footprint expands from Africa to Australia, India is in a position to offer its service to neighbouring countries. 

Though primarily meant for aviation, GAGAN’s capabilities can be utilised in many other user segments such as intelligent transportation, maritime, highways, railways, surveying and the telecom industry.

GAGAN Message Service (GMS) can relay alerts to deep-sea fishermen, farmers, and disaster affected people at the time of natural calamities.