“India should have its own positioning satellite system”

What is mandate of Airports Authority of India (AAI)?

As designated by International Civil Aviation Organisation (ICAO), AAI is mandated to control and manage the Indian airspace extending beyond the territorial limits of the country, i.e., land airspace of 1.05 million NM2 and oceanic airspace of 1.75 million NM2. [NM Nautical Miles]

What role AAI is playing in GAGAN?

Yes, AAI is committed to provide SBAS over Indian airspace as per Communication, Navigation, Surveillance / Air traffic Management (CNS/ATM) plan envisaged by ICAO. As you may be aware that Indian airspace is falling between coverage area of European Geostationary Navigation Overlay System (EGNOS) on the West and Multi Functional Transport Satellites (MTSAT) Satellite – Based Augmentation System (MSAS) (Japan) on the East but defi nitely not in the service area of both. It means that no Global Navigation Satellite System (GNSS) integritymonitoring signal will be available over Indian airspace. To bridge the gap between the coverage areas of EGNOS & MSAS and to facilitate seamless navigation to the aircraft from West-East and vice-versa, therefore GAGAN is a requirement. As you know that GAGAN is a

technology driven project and is still evolving. It has been envisaged that Department of Space (DOS) / Indian Space Research Organisation

(ISRO) will be in the right position to drive the project whereas AAI will provide the requisite fi nancial, technical manpower and all the other supplementary support for the project.

In what activities of AAI Global Positioning System (GPS) are used at present?

At present AAI is using GPS constellation for airport cartography application but in future GPS will be used for surveillance and navigation purpose. AAI is planning to conduct Automatic Dependent Surveillance –Broadcast (ADS-B) trials over Bay of Bengal and Arabian Sea where installation of Radar is not possible; therefore surveillance becomes diffi cult for enroute aircrafts. In this area GPS plays an important role as position locator in user-friendly environment. The position of the aircraft

will be displayed on ground display console, which will help the Air Traffic Control offi cers (ATCO’s) to monitor the progress of the flight. Secondly GPS will be used as core constellation of GAGAN. This core constellation will be augmented with Geo- Stationary Earth Orbiting Satellite (GEOS) i.e. GSAT-4, which will carry the required navigation payload for GAGAN. Thirdly GPS constellation is being used in Airport cartography for preparing Grid maps, zoning map etc. Therefore AAI is /will be using the GPS constellation in the major functions of CNS/ATM activities.

What is the future plans of AAI regarding GPS?

As such GPS core constellation belongs to Department of Defense (DOD) US. Now US Government has plan to modernize the GPS signal by introducing new frequency i.e. L5 which will be delivering more Carrier to Noise ratio power and less affected by Ionosphere as compared to the L1 and L2 frequencies. ISRO has made provision of L5 frequency in GSAT- 4 satellite payload, planned to be launched in the last quarter of 2006.

What are visible impacts of the introduction of GPS in AAI?

It is a right step. For civilian purposes, one does not require highly accurate and detailed maps. The needs are different. Hence, enabling access to non-sensitive geo-spatial information for developmental projects and civilian purpose is a welcome step.

The GPS system is under US control. Is it sensible to depend on this system?

As explained earlier, in the field of surveillance, we will able to monitor the entire Indian airspace under user-friendly environment. This will provide great help to AAI for safety of aircraft and reducing the congestion in the Indian air space. In this environment new concept of RNAV (Area Navigation) can also be implemented.

In the fi eld of navigation, it will provide seamless navigation over Indian airspace. RNAV can be further redefi ned with less separation and will help in reducing the airspace congestion. GAGAN will help further to dismantle terrestrial en-route nav-aids.

GAGAN signal will be available to the all Indian airports for navigation as well as precision approach landing. Only AAI has to develop the landing procedure with GAGAN parameters. It will further improve the accuracy of grid map and charts prepared by AAI based on the survey done by department of cartography (AAI).

How do you see the dependence of India on US based GPS system?

As GPS system belongs to DOD US and they took more than 20 year to bring this technology and provided services to the civil users free of cost. India is fourth country, which has decided to have own augmentation system based on GPS system. One fear will be always if US withdraws the GPS signal due some reason, the GAGAN system will collapse. So I feel that India should have its own positioning satellite system like GPS.

How do you see the developments regarding the development pertaining to Galileo?

I understand Government of India as recently signed MOU with European Union (EU) to participate in the Galileo Program. EU is implementing Galileo. The core system will have 30 satellites and is likely to be available by 2008 as per the existing schedule. Let’s see how does it go.

What is the Government of India’s policy towards GLONASS?

GLONASS is owned and maintained by Russian Federation. The system is depleted and number of serviceable satellites in orbit has depleted very much. Government, I understand, is taking note of it.