What is a Navigation System?
A navigation system is an electronic system that makes use of either radio waves or satellite signals or combination of both to help in navigating by streamlining the correct geographical position of a place. However, as the name suggest the use of navigation system is not limited to just identification of a route. It goes further and includes locating a place, distance calculation, speed monitoring, traffic signalling etc.
Generally navigation systems makes use of two devices, one could be located within the carrier or on board a vessel/vehicle or could be located some-place else, connected with the other through medium of radio signals or satellite communication or combination of either of these.
In the common parlance the navigation system is commonly known as GPS or the Global Positioning System. However it is not synonymous to it, as GPS which is a U.S. based navigation system accessible from around the corner is a part of Global Navigation Satellite System, but there could be specific navigation system designed for identified usages like for air traffic control and monitoring too and areas.
India’s Navigation System
In the recent times, with increasing technological initiatives and development, India too has come up and deployed its own navigation systems. This includes GAGAN (GPS Aided Geo Augmented Navigation) system, safety navigation for the railways and the IRNSS that is Indian Regional Navigation Satellite System also called NAVIC (Navigation with Indian Constellation), the newest member of Global Navigation Satellite Systems. With these systems India seeks to reap the benefits of seamless navigation for both civil and authorised purposes over air, land, inland and maritime. With the given triad India has joined the elite club of few countries which have operational navigations systems of their own.
The GAGAN project deployed for the Indian Airspace, ensures the safety of the civil aviation in India through additional accuracy, availability, and integrity necessary for all phases of flight, from departure, en-route to landing, to all suitably equipped aircraft and qualified airports within the GAGAN service volume. A joint effort of AAI and ISRO, GAGAN primarily provides an all-round air traffic management system along with other additional services. GAGAN works in consonance with other international SBAS systems like US-WAAS, European EGNOS, and Japanese MSAS etc. Its operation extends from Africa to Australia and has expansion capability for seamless navigation services across the region.
Of these, IRNSS is the most comprehensive navigation system by far put in place by India. The other countries with such navigation system includes USA’s GPS, Russia’s GLONASS, Europe’s GALILEO and China’s BeiDou. The entire system will become functional by June 2016, once India launches all the satellite payloads of IRNSS and position it to the required co-ordinate.
Evolution & Objective
For long India, like many other countries, had been dependent on the services that was being rendered by the foreign navigation systems. The usage and availability of satellite data depended largely upon how good a relations were maintained with said countries.
This technological dependency brought with it the grave vulnerability especially in the case of hostile situations. The immediate reason suggested by many, for India to initiate an indigenous navigation capabilities was Kargil War in 1999, when USA denied India access to vital satellite based information. Though the claim never substantiated it clearly highlighted the gravity of having an indigenously controlled satellite system in a tight-knit geo polity. However, officially the programme got government sanction only by 2006.
Secondly, the availability so far of the satellite data was without any contractual services obligation that gave an easy escape for such service provider to withdraw their services at any point of time.
Thirdly, the accuracy was a major issue. The data supplied lacked precision which was a major hindrance considering topography and varied geographical unit that existed in India.
All these issues brought up major challenges for both defence and civilian administration that were to be resolved deftly. ISRO commenced the project with the announcement that installation will be completed at the rate of one satellite per year on board PSLV’s to provide navigation, position and timing services.
The IRNSS consists of three elements Space, Ground and End User. It’s space component consists of 7 satellites, 3 in geostationary orbit (GEO) at 32.5° East, 83° East, and 131.5° East longitude and 4 in geosynchronous orbit (GSO) cross the equator at 55° East and two at 111.75° East for accurate real time positioning and timing. The satellites shall be placed at an altitude of 36000 km above earth’s surface.
The ground station component of IRNSS consists of Master Control Centre that will run navigational software, eight reference stations and Indian Land Uplink Station. They together shall work upon tracking satellite orbits, collecting data and updating satellite navigation. With this infrastructure India seeks to provide the accuracy of +20 metres in navigation. The end user unit shall contain of antennas and receiver-processors.
The system has been designed in a manner to provide ‘real time’ positioning, navigation and timing covering India as well as region extending up to 1500 kms from its boundary, which is its primary service area. ISRO further clarifies that the project will have and Extended Service Area that lies between primary service area and area enclosed by the rectangle from Latitude 30 deg South to 50 deg North, Longitude 30 deg East to 130 deg East.
Utilities of this project
The navigation system has two categories of services provided. One is the Standard Positioning System (SPS) available to all the users based in India and the other will be Restricted Services, which are encrypted service available exclusively for the authorised users.
Science & Technology plays decisive role in building military strength of a country. In terms of Military Application, the project will be a force multiplier for the Indian Defence Unit. The wide spectrum of utility it serves from target fixing, missile and weapon delivery, avoiding civilian causalities, unit location and direction, vision clarity in bad weather etc. will enhance the capacity of defence both war and peace time.
As provided by ISRO few of the stated purposes include Terrestrial, Aerial and Marine Navigation, Disaster Management, Vehicle tracking and fleet management, Integration with mobile phones, Precise Timing, Mapping and Geodetic data capture, Terrestrial navigation aid for hikers and travellers and Visual and voice navigation for drivers. Government has recently marked 170 areas where the services of the system can be deployed.
Further with an extensive coverage, one of the stated future use of the project includes sharing of the project with the SAARC nations. This will help in integrating the regional navigation system further and a diplomatic goodwill gesture from India towards countries of the region.
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