“ The range for GAGAN extends far beyond Indian boundary lines. It reaches up to Africa and south East Asia. It is a immense air space that we can supervise with this engineering ”
Praful Patel, curate of province for civil air power
“ GAGAN will be the universe ‘s most advanced air pilotage system and farther reinforces India ‘s leading in the head of air pilotage. GAGAN will greatly better safety, cut down congestion and enhance communications to run into India ‘s turning air traffic direction demands. ”
Andy Zogg, Raytheon Network Centric Systems,
Vice President, Command and Control Systems
GPS, GLONASS and the proposed GALILEO Navigation Satellite Systems are meant for supplying place and timing information for a assortment of applications. However, for safety critical applications for civil air power like preciseness attack, the stand-alone basic configurations can non run into the demands in footings of truth, unity and handiness. In the recent old ages, there has been broad spread growing in the development of orbiter based augmentation system which is portion of the Global Navigation Satellite System ( GNSS ) , for enroute pilotage, preciseness attack and landing of the aircraft.A For this intent, the basic configurations are augmented by an sheathing system. The U.S has put up its WAAS, Europe its EGNOS and Japan its MSAS in their several parts. However this still leaves a spread in the Indian subcontinent part.
The Airports Authority of India ( AAI ) has decided to implement an autochthonal satellite-based regional GPS augmentation system known as Space based Augmentation System ( SBAS ) as portion of the Satellite-based Communication, Navigation, Surveillance ( CNS ) / Air Traffic Management ( ATM ) program for civil air power. Indian Space Research Organization ( ISRO ) , along with Airport Authority of India ( AAI ) has worked out a joint plan to implement the Satellite Based Augmentation System for the Indian part to make full the spread between EGNOS and MSAS. The undertaking called GAGAN ( GPS Aided Geo Augmented Navigation ) has been taken up with an aim to show the SBAS engineering over the Indian part. There is a program to hold an operational system to supply a seamless pilotage installation in the part, which is interoperable with other SBAS.The system would operationalise a satellite-based Indian Flight Information Region in concurrence with all states from Southeast Asia, Gulf and West Asia and the eastern seashore of Africa.A GAGAN will supply seamless coverage ofA aerate trafficA from south Asia to Africa and connect to the systems of Europe and Japan. So far, merely the US, Europe and Japan have developed similar capablenesss.
The air traffic in India is increasing at a enormous gait. In the following five old ages, theA Indian airspaceA will acquire more crowded and the opportunities of accidents may increase. Even though the GPS installations are available with the commercial air hoses, still the truth is non guaranteed. India is situated near the locality of equator. In the equatorial part the ionospheric fluctuations are really prevailing which affect the GPS as good GEO signals. Entire airspace country controlled by AAI is 6 million Square Km. Majority of the Indian air space falls in pelagic part, where it is hard to supply pilotage signal through conventional navigational AIDSs.
To cut down the opportunities of futureA air catastrophes, AAI and ISRO is implementing the GAGAN. GAGAN is a joint enterprise and has cost Rs 700 crore. Of this, Rs 200 crore has come from the ISRO and remainder from the authorities of India.
aˆ? To better GPS truths ( from 30m to 6m ) , handiness and continuity for civil air power. aˆ? Position Accuracy achieved & lt ; 3 metres over Indian Region ( Specs: 10 metres )
Bangladesh and Nepal have already expressed their involvement in our system, ”
The GAGAN system receivesA GPS signalsA from international pilotage orbiters, but it boosts their truth, locking a plane ‘s place anyplace inA IndiaA to within three metres. This is made possible by tracking orbiters from locations acrossA IndiaA and comparison and rectifying their informations centrally ( in Bangalore ) . The GAGAN system will dwell of a countrywide web of having Stationss that are exactly surveyed to compare the place determined from GPS orbiter signals against the location of the receiving system. The ascertained deltas ( differential places ) will so be sent to a maestro control Centre where computing machine processing will generalize the information to bring forth correcting deltas for GPS signals anyplace within the web. These rectifying deltas will be relayed via geostationary orbiter to civil aircraft so more precise holes of their place can be derived from GPS orbiter signals.
The Gagan system consists of land and the infinite sections. The land section will dwell of mention Stationss ( called the IRNES, Indian Reference Stations ) , ab initio one mission control Centre ( Indian Master Control Centre, INMCC ) and an uplinking station ( Indian Navigation Land Uplink Station, INLUS ) . The infinite section consists of a pilotage warhead onboard Indian geostationary orbiter. The user section consists of SBAS receiving systems in the aircraft, capable of having GPS signals and corrections from geostationary orbiter.
INRES are configured as multiple receiving system ironss for obtaining the measuring from the GPS and GEO orbiters. They have minimum two indistinguishable GPS receivers/ aerial subsystems to have GPS signal ( L1, L2 & A ; L5 ) and GEO signals ( L1 & A ; L5 ) form all the orbiters in position. A sum of 15 mention Stationss are planned located all over India. These Stationss are so chosen to supply service coverage over Indian air space.
INMCC is major subsystem of the GAGAN undertaking and its map is rectification and safety subsystem, operation of care subsystem, service monitoring subsystem and informations communicating subsystems. Using suited pilotage package INMCC processes the informations received through communicating nexus from the all the INRES. It besides estimates the unity and handiness of the GPS orbiters and uplinks these parametric quantities via INLUS for broadcast to the user receiving system through GEO. The INMCC for GAGAN is located at Kundanhalli, Banglore. The installing and integrating of this major subsystem has been completed.A
INLUS land station will have messages from INMCC and convey the rectification to the geostationary orbiter for broadcast to the user platform. The INLUS besides provides GEO satellites runing information and corrections to GEO satellites redstem storksbills. It is besides located in Bangalore.
A geo-stationary pilotage warhead in C set and L1 and L5 frequences ( L set ) will be carried on an Indian Geo-stationary satelliteA which will convey the rectification signal to the terminal user ( the aircraft ) .
The GAGAN system will hold a full complement of the SBAS inclusive of land and onboard section. Three stages have been identified for making the Full Operational Capability for GAGAN.
1.Technology Presentation System ( TDS )
2. Initial Experimental Phase ( IEP )
3. Concluding Operation Phase ( FOP )
Technology Demonstration System ( TDS ) : The aim of the TDS stage is to develop autochthonal capableness in SBAS execution. Under the TDS, ISRO has established the necessary land and infinite section for presentation of SBAS working for enroute pilotage, non-precision attack ( NPA ) and Cat I set downing capableness over a limited air space ab initio. The public presentation aim of this system is to run into the ICAOs Standards and Recommended Practices ( SARP ) demands.
The land section constellation for the TDS stage included edifice eight receiving systems to cover the state and the uplinking unit collocated in Bangalore with the maestro control centre. The onboard section consists of a pilotage warhead onboard Indian geostationary orbiter.
Initial Experimental Phase ( IEP ) : After the successful completion of the TDS, redundancies have been provided to the space-segment, INMCC, INLUS and system proof carried out over the full Indian air space in association with an international bureau. The conventional navigational AIDSs will go on to be operational as premier manner. The activities during the Initial Operational Phase will be defined in greater item after deriving experience during the TDS stage.
Final Operational Phase ( FOP ) : During this stage, the GAGAN plan will be
matured. Extensive trials would be carried out to set up the system stableness of
assorted elements of the system as a whole. Additional INRESs will be established as required and the communicating systems will be established with all redundancies. The system will be put in extended usage for its rating with regard to ICAO SARPs. Certification and proof of the system will be completed before declaring the system operational.
Use of GAGAN
The use of GAGAN is chiefly for air power sector, nevertheless it has some indirect affects every bit good in air power related every bit good as other sectors.
The system would assist in Air traffic commanding ‘precision attack ‘ while set downing at all airdromes in this huge part. It would non merely ensue in nest eggs on ground-based radio detection and ranging systems, but besides better air traffic capacity through reduced aircraft separation, that is more planes can be accommodated in a limited airspace.A GAGAN would besides heighten air-to-air surveillance and supply minimal safe height warning, besides installations for controlled flight into terrain, the absence of which becomes a major cause for aircrashes while landing.A The system provides enhanced safety characteristics for the air hoses as they would be able to hold preciseness attack counsel towards tracks in any conditions conditions
Fuel salvaging including enabling aircraft to wing on direct straight-line routes.A Currently, the planes fly over the land-based radio detection and rangings which are non installed in a consecutive line. GAGAN would assist them voyage on a consecutive line as it is dependent on satellite path counsel and therefore heighten fuel nest eggs.
Navigation: Aid air traffic from Southeast Asia to Africa, including over the high seas in the huge part. The system would besides assist in marine pilotage.
Cost salvaging The cost nest eggs in utilizing a system like GAGAN accrue from the fact that its land system does non necessitate to be duplicated for each track, as is the instance for an ILS. Besides due to cut down work load of flight crew and Air Traffic Control towers, The GPS signals, every bit good as the correcting deltas, can be made available to aircraft for any track within the web utilizing orbiter based communicating. GAGAN is a orbiter based pilotage system that will function as a low cost replacement for Instrument Landing System ( ILS ) .
Redundancy: In add-on to utilizing GPS signals, GAGAN will be able to utilize timing and positioning signals from GLONASS and the proposed GALILEO, therefore supplying redundancy.
Knowledge base: One indispensable constituent of the GAGAN undertaking is the survey of the ionospheric behavior over the Indian part. This has been specially taken up in position of the instead unsure nature of the behavior of the ionosphere in the part. The survey will take to the optimisation of the algorithms for the ionospheric corrections in the part which would later assist in our ain orbiter pilotage system.
Certain assorted maps include hunt and deliverance operations,
study and function ( Geodetic & A ; Geodynamic ) and besides use in rail and route conveyance.
India plans to utilize the GAGAN system ab initio in 40 campaigner airdromes that will necessitate CAT-1 or shut to CAT-1 capableness in the close hereafter.
Even though the system is assuring and radical there are still certain drawbacks in the present system. These are:
Accuracy is non sufficient ( even with Selective Availability off, perpendicular truth & gt ; 10m )
Current GPS configuration can non back up demands for all stages of flight
Availability and continuity must be met
Integrity is non guaranteed ( all orbiters are non monitored at all times ; time-to-alarm is from proceedingss to hours, no indicant of quality of service )
GAGAN: non stand-alone, but a regional augmentation to GPS
However, today ‘s WAAS receiving systems wo n’t be able to utilize IRNSS signals without important alterations. They ‘re merely designed to utilize the GPS L1-band frequences as against l1, l5 and S set for IRNSS.
Gaagan is a bold enterprise in the field of air power and is in sync with the quickly turning air power industry in India. It non merely helps the air power sector but will besides indirectly have an consequence on other sectors as good. The system was approved in 2008 and is now planned to be operational in 2011. India ‘s first GPS/SBAS warhead, the GAGAN sender on the GSAT-4 geostationary orbiter, disappeared into the Bay of Bengal on April 15 when its doomed GSLV-D3 launch vehicle veered off class. Subsequent portion of the pilotage warhead are planned to be launched by the GSAT 8 and GSAT 9 orbiters. Unfortunately the Rs 744-crore joint programme of the national infinite bureau ISRO and AAI is already lagging by at least five old ages.