SCIENCE IN INDIA | SPECIAL /////////////////////////////////////// Indian Space Programme Past Pride & Future Challenges M. Annadurai ECOGNISING the potential of space as a catalyst for Communication Satellites development, the Indian Space Research Organisation Satellite links are the primary means of connectivity to remote R(ISRO) devised its space programme with the objective of and far-fl ung regions of the country – they are the backup links “Harnessing space technology for national development, while for terrestrial connectivity in the mainland too. Communication pursuing space science research and planetary exploration” satellites play a vital role in today’s digital era focusing on the since its inception and this has remained the fundamental tenet utilisation of satellite communication throughout the country. around which the Indian Space Programme has evolved. The technology has matured substantially over the past three The ISRO Satellite Centre has rolled out 100 satellites decades and is being used on commercial basis for a large capable of providing services in various application domains number of applications. like communication, meteorology, remote sensing, navigation Today, we have 15 operational communication satellites and space science explorations. These satellites are continuing in orbit supporting 285 transponders in C, Ext C, Ku, Ka/ to serve the key sectors of the Indian economy such as socio- Ku and S-band for diverse applications like Television, economic security, sustainable development, disaster risk DTH Broadcasting, Radio Networking, and Mobile Satellite reduction, and governance at large. Services to exploit the unique capabilities in terms of coverage 28 | Science Reporter | May 2018 / /////////////////////////////////////////////////////////////// Cloud cover as seen by INSAT-3D Satellite over India and surrounding areas and outreach. The prominent users of the transponders are Tele Education projects through EDUSAT were BSNL, Doordarshan, DTH and TV operators, All India exclusively meant for educational services to cater to a wide Radio, Government users, Public Sector units, Private VSAT range of interactive educational delivery modes like one-way operators, banking and fi nancial institutions. TV broadcast, video conferencing, computer conferencing, Communication satellites have been a major catalyst for the web-based instructions, etc. EDUSAT had manifold objectives expansion of television coverage in India. Satellite television – to supplement the curriculum-based teaching, imparting now covers 100% area and 100% population. All of the Satellite effective teacher training, providing access to quality resource TV channels are digitalised. DTH services are becoming persons and new technologies, thus taking education to every popular with the introduction of premium services like HDTV nook and corner of India. services, On-demand movie services, etc. High power Ku-band It also provided connectivity to schools, colleges and higher transponders are used to support DTH television service with levels of education and also supported non-formal education the smallest dish antenna all over India. The free-to-air DTH including development communication. About 15 million service “DD Free Dish of Doordarshan offers 59 TV channels. students got benefi ted through the EDUSAT programme. More than 1404 Satellite Earth Stations of different size Mobile Satellite Services with voice communication are operating in the satellite network of BSNL, government provide communication links especially during disasters when users, closed user group, commercial users and broadcasters other means of communication are broken down. It can be and are being utilised for telecommunications/broadcasting used from any location in India for emergency communication. applications. About 2,74,000 VSATs are being used in star/ Transmit and receive frequencies of the terminal in S-Band mesh connectivity of various sizes and capabilities. could be made between any satellite and local phones. Telecom services, GSM connectivity, ATM/Banking Radio networking through satellites provides reliable high- connectivity through about 19000 IPSTAR VSATs, about 5000 fi delity programme channels for national as well as regional Digital Satellite Phone Terminal (DSPTs) Networks of Bombay networking. At present, 419 All India Radio (AIR) stations and Stock Exchange and a number of other captive government about 607 radio transmitters have been equipped with receive networks are also working with Indian satellites. terminals, and 21 radio channels of AIR are broadcast through The ISRO Telemedicine programme has also been DTH platform of Doordarshan. connecting remote/rural/medical college hospitals and Mobile Units through the Indian satellites to major specialty hospitals As a part of Satellite Aided Search and Rescue programme, in cities and towns. The ISRO Telemedicine network covers India is a member of the international COSPAS-SARSAT various states/regions across the length and breadth of our programme for providing distress alert and position location country. Presently, around 130 Telemedicine nodes are service through satellite system which provides coverage to a operational across the country. large part of the Indian Ocean region rendering distress alert May 2018 | Science Reporter | 29 //////////////////////////////////////////////////////////////// services to Bangladesh, Bhutan, Maldives, Nepal, Seychelles, Using the fi rst generation NavIC Receivers, tracking Sri Lanka and Tanzania. applications were demonstrated in the areas of road transport, railways, shipping, etc. NavIC capabilities have also been Navigation – NAVIC and GAGAN Applications demonstrated for time synchronisation applications in power ISRO has also entered into satellite-based navigation system operations. applications through GAGAN & IRNSS. GAGAN will redefi ne A fi shermen App has been developed using the messaging navigation over the Indian airspace, IRNSS will provide capability of NavIC. A compact NavIC device communicates independent and self-reliant satellite-based navigation services to the fi shermen’s smart phone via Bluetooth the message over the Indian region. information to the App. This App provides position information ISRO and Airports Authority of India have implemented for navigating to the potential fi shing zone, alert messages the GPS Aided Geo Augmented Navigation (GAGAN) project on rough sea and weather status and warning messages on as a Satellite Based Augmentation System (SBAS) for the approaching international water boundaries. Indian airspace. The objective of GAGAN to establish, deploy Ruggedised hybrid (NavIC & GPS/GAGAN) receivers and certify satellite-based augmentation system for safety-of- have also been developed and tested on PSLV & GSLV launch life civil aviation applications in India has been successfully vehicles for determining trajectories and the performance was completed. The system is inter-operable with other international found to be satisfactory. SBAS systems and has expansion capability for seamless navigation services across the region. Remote Sensing Applications GAGAN provides the additional accuracy, availability, Earth observation satellites are application-oriented focusing and integrity necessary for all phases of fl ight, from en route towards providing continuity of services in areas like land through approach for all qualifi ed airports within the GAGAN and water resource observation, ocean and atmosphere, service volume. Besides these, they will also provide benefi ts cartography & large-scale mapping, and microwave imaging. beyond aviation to many other user segments such as intelligent Today 15 satellites are in the orbit catering to a wide variety of transportation, maritime, highways, railways, surveying, applications like fl ood mapping, landslide inventory mapping, geodesy, security agencies, telecom industry, personal users agriculture assessment, underground water assessment, urban of position location applications, etc. planning, forest mapping, etc. IRNSS, the Indian Regional Navigation Satellite System India is one of the most fl ood-prone countries in the world. named as NavIC, is an ISRO initiative to design and develop Floods occur in almost all river basins in India. Both optical an independent satellite-based navigation system to provide and microwave satellite data are being used and information is positioning, navigation and timing services for users over the disseminated to the concerned Central/State agencies. Satellite- Indian region. The system is designed with a constellation based imageries due to their synoptic coverage are the best of seven spacecraft and a vast network of ground systems tools for assessment of the extent of fl ood-affected areas and operating all the seven satellites. IRNSS-1A to IRNSS-1G are the damage to the infrastructure facilitating the decision makers fully operational designed to provide a position accuracy of to plan for relief operations. better than 10 metres for navigation services. The major natural disaster that affects the coastal regions of India is cyclone. With 7500 kilometres of coastline it is exposed to nearly 10% of the world’s tropical cyclones. Using appropriate models and satellite data, ISRO is supporting the efforts of the India Meteorological Department to predict the tropical cyclone track, intensity and landfall. After the formation of cyclone, its future tracks are regularly monitored and predicted using a mathematical model. These track predictions