Reason to start working on the system as per the article :

"It is a culmination of 17 years of rigorous work by Indian space scientists. India took a firm decision on IRNSS in 1999 after the US government refused to share GPS data that would provide vital information on Pakistani troops position during Kargil war. As in the previous launches of the IRNSS satellites, PSLV-C41 has also used ‘XL’ version of PSLV equipped with six strap-ons, each carrying 12 tonnes of propellant."

So my phone can use these satellite navigation systems: U.S. GPS, Russian GLONASS, European Galileo, Chinese BeiDou and Japanese QZSS.

I guess one more doesn't hurt, huh?

It's curious how major powers all want to have their own satellite navigation systems.

Edit: QZSS is a regional system, and not due to start until November 2018, yet my phone detected one of those satellites earlier about 2-3 weeks ago. Interesting, especially considering I'm nowhere near Japan. Unless, of course, it was a bug or some weird error case. Or maybe QZSS was doing some early testing?

Curious. Do missile systems also lose track of their position midway through a flight like our phones? Are the receivers radically better than the ones in our phones? What happens if a missile loses its coordinates because of a bad signal? Does it just continue and keep track of its position based on the last known position or does it abort? If it cannot lock on to a GPS signal at the start of its flight, does it fail to take off?

This is both amazing and sad. Amazing because its the emergence of (yet another) a space power, and amazing because it gives the world more and presumably healthy competition for a globally useful technology.

Sad because "we built, planned, funded and launched this awesome technology because ... war"

Humans. What a species.

How does this compare to the Americans GPS? Is it as good or was it designed with different constraints in mind?

Now I'm just waiting for GPS chip manufacturers to add support. Should increase resolution for those in the subcontinent :)

yet China has Beidou navigation system

IMHO, it's pretty useless compared to the current government and country's scenario. They better electrify the villages and provide better sanitation to the people rather then spending millions on mars, moon missions to prove their superiority! What a waste!

It may stop working in a year or two like any of their indigenous inventions!!

I'm not undermining any Indians, nor the way they work but as they are governed is by far the worst considering the current and past situations.

No quality, no nothing.

These are essential national security assets, used for military purposes, and which a hostile (or even neutral) owner could turn off in case of war. The civilian use-case is a handy side benefit.

If you build your missiles to work using gps (as another poster pointed out), then you also want those to work if the US decides to not let you use the gps system.

> ...my phone detected one of those satellites earlier about 2-3 weeks ago. Interesting, especially considering I'm nowhere near Japan.

Could be an error, but you could just be in Australia or just about anywhere on the Eastern hemisphere. The orbits are geosynchronous and thus very high.

https://en.wikipedia.org/wiki/Quasi-Zenith_Satellite_System#...

How can you tell which nav systems your phone can see?

QZSS has been in test phase since 2010, and has had a full constellation of 4 satellites since last year.

I don't think IRNSS covers regions outside South Asia.

Missile have their own very complex on-board guidance systems that don't require GPS at all. Newer missiles might use GPS as an extra layer of calibration, but I doubt they rely on it and most likely discard it if it's way off (otherwise GPS interference could potentially jam a missile).

Ballistic missiles use stars mid-flight and inertial guidance system during the terminal phase. Cruise missiles follow terrain.

Many of those systems were designed before GPS became operational, but even now relying on GPS is not particularly prudent.

The main things that cause loss of GPS 'lock' are the satellite signals being blocked (buildings, terrain, people, etc in the way), and multipath (signals being reflected off buildings, terrain, etc). A munition a few thousand feet above the ground has none of those things.

(There's also 'GPS jamming', which is totally a thing in war, but that's not really 'like our phones', generally.)

As other posts have mentioned, though, GPS is simply one input into weapons systems, not the input into weapons systems.

> Do missile systems also lose track of their position midway through a flight like our phones?

Civilian grade GPS receivers are intentionally crippled to stop working above some altitude/speed limits.

EDIT: It seems that the COCOM limits apply only after "1,900 km/h at an altitude higher than 18,000 m".

However, looking at the ublox receivers as an example, they have to be explicitly configured to operate at aircraft-level speeds, which smartphones likely aren't.

They not only have better receivers than in our phones, they have an entirely separate signal they can use- P-code (https://en.wikipedia.org/wiki/GPS_signals#Precision_code).

It's encrypted, so it's not for civilian use, and the ability to look at two signals of different frequency at the same time means that they have been able to have much more robust GPS than civilians for awhile.

Airplanes are big metal tubes that can block GPS signals, that's probably the problem you're having.

Technology tends to be value-neutral. The application of technology could be for evil or for good. To claim that the primary purpose of the Indian Regional Navigation Satellite System (NAVIC) is for belligerent activities is to claim knowledge of the intentions of the Indian government at the time of the system's creation.

Couldn't it be just as likely or more likely that multiple positive and negative rationales were in play at the time?

  - reduced dependency on the US
  - chance to learn something for oneself
  - give boost to the Indian aerospace fields
  - home-grown navigational abilities for war but also for civilian use
  - pride, wanting to be seen as a global tech leader
  - any other number of things?

I think it is amazing that we now have not one (US) but five (US, EU, CN, IN, RU) navigational satellite systems, two of which (US, RU) are globally operational and two more will be (EU, CN) by 2020. What interesting times we live in.

Civilization is having the gun and choosing not to use it. Not bothering with the gun, singing kumbayah and depending on human goodwill is never going to work.

Human history shows there are competing interests who are willing to kill to get their way. Those lulled into a sense of complacency by fantasy narratives about the how the world works learn the hard way.

See the list of recent victims in the middle east starting from Iraq, Libya and now Syria. Tens to hundreds of thousands killed, families destroyed, infrastructure, education, healthcare destroyed and countries sent back decades if not hundred years in service of human greed.

And 50 years later commentators will dismiss these 'third world' countries as utter failures and insinuate some deficiency without any context of history. You can debate for ever but the man with the biggest gun gets the last word.

Not war, but self-preservation.

Historical fact: India has fought 5 wars since 1947, but was never the aggressor. India, or any country for that matter, doesn't choose its neighbors.

Remember, the internet was a result of DARPA's work.

War is the mother of all inventions.