Bharat Rakshak

Merril wrote:

Singha wrote:+1 to that. as I mentioned the only way to make sure people develop apps and things for it is make it mandatory for all smartphones sold in india beyond a certain date to carry the IRNSS signal. india is now the worlds 2nd or 3rd largest smartphone market.

GOI simply has no clue how to leverage the market.

Singhaji,

How does the use of IRNSS over GPS benefit the aam Abdul in India? I mean other than the fact that that it Indian, is there any specific advantage?

The only thing that I can think of is that the the phone/device manufacturers have to pay some royalty to the US gov for the usage of the signals. However due to the sheer number of devices that use GPS nowadays, I don't suppose that's the situation.

Edit: I see suryag has already asked a similar question.

SSSalvi wrote:Right now the smartphones have built in GPS because the GPS receivers used are available at throwaway cost due to sheer scale of numbers being manufactured. Developing IRNSS specific receivers and incorporating those in cellphones ( or even stand alone GPS receivers for civilian use ) will be at a prohibitive cost. So my gut feeling is that this system will become only as a demo/learning step to demonstrate that we can build our own if required.

We will also show that with just a set of 7 satellites we can have visibility at least 4 to 5 satellites at any given time over a particular sector of Earth.

Utilitywise I don't see any use.

Lalmohan wrote:on the GPS system - 3 is ok (for rough location), but 4 is accurate, or a ground station can be used to fine tune

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).

Almost after fifty years of the GPS, the Indian space agency ISRO is found making great strides in the navigational field. On July 1, 2013, ISRO successfully launched its first navigational satellite Indian Regional Navigation Satellite System (IRNSS-1A) into the geosynchronous orbit and plans to develop a constellation of seven satellites with a possible addition of four more satellites later. India is expected make IRNSS fully operational by 2015.

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.

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. For many years the GPS remained mainly a military gizmo with limited civilian utility. It was only after May 2000, when the US turned off the Selective Availability Feature (intentional degradation of the GPS signal), that the GPS market grew rapidly, particularly in the transportation sector. Presently, various GPS features in the civilian domain are available with reasonable accuracy. Increase in the market volume also lead to lowering of prices both for hardware and software. During 2012, the volume of global navigation market exceeded 80 billion dollars. Interestingly, the defence market share is approximately only 2% of the entire volume.

Irrespective of a small volume, the GPS has critical defence utility. The volume of market in the defence sector should not be viewed in ‘isolation’ as an indicator of its defence utility. As such in the civilian area there are far too many customers globally while in the defence sector very few countries are the actual users of GPS technology. All modern day state-of-art defence equipments are dependent on space navigation technology. The GPS is important not only for the operations of military platforms like ships, aircrafts and tanks but also for accurate targets. The modern day war fighting concepts like network centric warfare are feasible only if the space based navigational aids are available.

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.

IRNSS is expected to provide various applications which include terrestrial, aerial and maritime navigation; disaster management; assisting hikers and travellers; vehicle tracking and fleet management; and providing visual and voice navigation for drivers which can be also integrated with the mobile phones.

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.

Recently, the US Secretary of State John Kerry’s visit to India for the Strategic Dialogue and the resultant joint statement issued on June 24 mentions that both India and the US willl take measures to ensure the compatibility-interoperability between the US GPS and the IRNSS. While not completely dismissing the GPS, there are two specific limitations in the Indian context. First, owing to the degraded signal or due to ‘selective denial’ of the services, defence activities do suffer. Second, there are some ‘dead zones’ (no signal) within the country where geographic limitations do hamper signal strength and quality. The IRNSS is expected to overcome both these difficulties.

In the field of global navigation, China has already made significant progress with its COMPASS (Beidou) system. China proposes to develop a global system consisting of 35 satellites and is already half way through. The system has been declared operational for the Asia-Pacific region. Importantly, the Chinese have committed to provide Pakistan with a ‘military quality’ signal.

India’s entry into the field of space navigation was much awaited. It is expected that ISRO will be able to launch the remaining six satellites within the next two years and operationalise the system to its full potential. Once up and running, the system is expected to meet India’s defence and security requirements and also offer various social and commercial benefits.

The Joint Precision Approach and Landing System (JPALS) is a military, all-weather landing system based on real-time differential correction of the GPS signal, augmented with a local area correction message, and transmitted to the user via secure means. The onboard receiver compares the current GPS-derived position with the local correction signal, deriving a highly accurate three-dimensional position capable of being used for all-weather approaches via an ILS-style display. While JPALS is similar to Local Area Augmentation System, but intended primarily for use by the military, some elements of JPALS may eventually see their way into civilian use to help protect high-value civilian operations against unauthorized signal alteration.

Airbus's modified A300-600ST transporters are set to become the first large type to be approved for satellite-based approaches using the new European Geostationary Navigation Overlay Service (EGNOS).

France's Pau Pyrénées airport became the first in Europe to conduct landing operations with a new accurate safety-of-life vertical guidance signal, made available on 2 March.

The European Space Agency says the A300-600STs' certification flights for the approaches are due to begin this spring.

"Airbus Transport became interested because their aircraft go to smaller runways that are not always [instrument landing system]-equipped," says France's directorate general of civil aviation. "They use Pau for training."

Eurocontrol has fitted the A300-600STs with the required equipment and supported development of the initial approach procedure through its EGNOS Pioneers scheme.

"Pilots don't need much retraining as EGNOS works is much the same way as the current ILS," the DGAC adds.

French authorities aim to implement EGNOS capabilities at regional airports, including Clermont-Ferrand, Marseilles - where Eurocopter performs helicopter certification work - and Le Bourget, which should be equipped before the Paris air show.

"Before a suitably equipped aircraft can perform EGNOS-based approaches to any runway, a dedicated approach procedure has to be published," says the DGAC, adding that 100 airports in France should be EGNOS-capable by 2020.

"From the point of view of navigation strategy we see many benefits, notably improving safety on smaller runways where no vertically-guided approach is available."

merlin wrote:GAGAN is designed to augment GPS . .

vasu raya wrote:^^^
the JPALS has 1 meter and better accuracy

vasu raya wrote:^^^

"Airbus Transport became interested because their aircraft go to smaller runways that are not always [instrument landing system]-equipped," says France's directorate general of civil aviation. "They use Pau for training."

Eurocontrol has fitted the A300-600STs with the required equipment and supported development of the initial approach procedure through its EGNOS Pioneers scheme.

"Pilots don't need much retraining as EGNOS works is much the same way as the current ILS," the DGAC adds.

Shrinivasan wrote:^^^ What are these challenges due to our proximity to the equator?

Acharya wrote:ditto

No need to call the ground control to flash runway lights. Special forces could land even if ATC is not in control of friendlies.

No need to call the ground control to flash runway lights. Special forces could land even if ATC is not in control of friendlies.

Neshant wrote:
As to why India is involved in practically all (glonass, gallileo, irnss) at great cost I don't understand.

But, we can never predict the behaviour of nations