IRNSS

Launching 

1. Indian Space Research Organisation (ISRO) will launch the first of seven satellites that will provide the country with an independent navigation satellite capability on July 1,2013.
2. A navigation satellite system uses a cluster of spacecraft that regularly transmit signals.Suitably equipped receivers can then use that data to work out their exact position.Vehicles, big and small, as well as aircraft and ships increasingly find their way using such navigation devices.

Other Navigational system

1. The best known and currently the most widely used navigation satellite system is the U.S. Global Positioning System (GPS), which became operational two decades ago. Russia too offers global coverage with its Global Navigation Satellite System (GLONASS). Europe is establishing its own global system, Galileo. Although the full constellation will be ready only by 2019, it plans to begin some services with a reduced number of satellites by the end of next year.
2. Last December, China announced operational services from its BeiDou Navigation Satellite System over that country and surrounding areas. It intends to launch more satellites and expand the system for global coverage by 2020. Japan has already launched the first of three satellites for its regional system that will augment GPS services.

Usability and Defense 

1. With seven satellites, the Indian Regional Navigation Satellite System (IRNSS) will broadcast its signals primarily over India and to about 1,500 km beyond its borders.
2. Military operations rely heavily on satellite navigation, and India’s defence requirements appear to have played an important part in the decision to establish an independent system. The operator of a foreign system can choose to deliberately degrade the accuracy of its signals, as the U.S. reportedly did with the freely accessible GPS signals when invading Iraq.
3. Apart from signals that anyone can utilise free of cost, satellite navigation systems, including the Indian one, provide an encrypted service that is restricted to those authorised to receive it.
4. India’s IRNSS, along with GAGAN, “is set to serve a potentially huge market across the sub-continent,” the report noted. (GAGAN, an abbreviation for “GPS Aided Geo Augmented Navigation,” is a satellite-based system implemented jointly by ISRO and the Airports Authority of India to improve GPS accuracy over the country as an aid for aviation
5. The US does, however, allow for accessibility of the GPS facility mostly for civilian purposes but the quality of signal made available is always in a degraded profile. Such signal is of no use for military purposes. In the case of the IRNSS, the position accuracy is expected to be in range of 15 to 20 meters while the GPS provides a signal approximately with 36 meters accuracy.

Advantage 

1. One of the biggest advantages of the IRNSS, once the system gets fully operational, is to reduce the dependency on the GPS. This would make India largely self-sufficient in navigational arena. Currently, India also uses the Russian system called Global Navigation Satellite System (GLONASS). ISRO has also developed a GPS supported geo-augmented navigation system (GAGAN) to assist the navigation of civilian air traffic over Indian airspace. It is expected that after both these systems become fully operational a potential synergy between IRNSS and GAGAN would evolve.

History 

1. For many centuries the sun and stars position guided humans to navigate the sea and travel the land. Even today, migratory birds take help from the ‘sky’ in their long-distance flight. Subsequently, the magnetic compass and the sextant assisted travel. But the real revolution in navigational techniques happened during the sixties with the invention of the space navigational system by the US military, famously known as the Global Positioning System (GPS).
2. For any space navigational system to successfully undertake global operations it has to develop a constellation of a minimum of 24 to 26 satellites. However, India is developing a regional system with 7 to 11 satellites based on the region’s requirement. Normally, GPS satellites are positioned in the Medium Earth Orbit (MEO), around 20,000 km above the earth’s surface. The IRNSS, however, is unique as three satellites will be in the geostationary orbit (36,000 km above the earth’s surface) and four satellites in the inclined geosynchronous orbit.
3. The GPS is a Cold War creation. One of the basic purposes behind developing this system was to assist the US submarines to launch a missile attack on a target with minimum error. Now, the GPS is used in the civil aviation and shipping sector as well as in fields like geodesy, cartography, land and water resources management, etc.
4. The GPS is important not only for the operations of military platforms like ships, aircrafts and tanks but also for accurate targets.

Technology

1. Pelican Imaging : This multiple-optics technology, at its simplest, allows users to adjust an image’s focus after the photo is taken, or allows a singe picture to have multiple foci. Focussed by Nokia.
2. HEVC (High Efficiency Video Coding) : The HEVC standard doubles data compression, while enabling far higher resolutions.Successor to MPEG-4 standard. Its USP is that it doubles data compression, while simultaneously enabling far higher resolutions, of up to 8,192×4,320 pixels.

Water Harvesting

1. Subsurface dyke is a structure that is built in an aquifer with the intention of obstructing the natural flow of ground water, thereby raising the ground water level and increasing the amount of water stored in the aquifer.