Indian GPS IRNSS

[Jeroen D]

Just came across this: http://www.hindustantimes.com/India-news/Bangalore/India-to-launch-first-navigation-satellite-in-June/Article1-1027588.aspx

Does anybody know how this would work from a device point of view. I own a whole bunch of Garmin and TomTom. They all lock onto the US GPS system. I'm not aware, never found a setting that would allow me to switch to a different GPS system.

As far as I understand the various frequencies and bands for the various GPS systems are standardized. But would that be the only difference. I.e. would a Garmin with its receiver tuned to the IRNSS frequencies work?

It's all very well having your satellites up in space and a few ground stations thrown in as well, but without devices it's still pretty useless. Here in India the IRNSS is probably pursued mostly based on defense consideration and I'm sure the army/air force will get their own devices. I'm just wondering for the regular consumer. How likely, how fast will we see the mainstream GPS manufacturers pick up this market.

Jeroen

[Jeroen Hoppenbrouwers]

The Indian system is not at all like GPS or GLONASS; they use geostationary and geosynchronous satellites and the frequency bands are different.

But there are 'some more' constellations out there:

http://en.wikipedia.org/wiki/Indian_Regional_Navigational_Satellite_System
http://en.wikipedia.org/wiki/GPS
http://en.wikipedia.org/wiki/GLONASS
http://en.wikipedia.org/wiki/Galileo_%28satellite_navigation%29
http://en.wikipedia.org/wiki/Beidou_Navigation_Satellite_System

Wikipedia says that the iThing uses both GPS and GLONASS, I am not aware of more coverage but I did not do a lot of research.


Hoppie

[Jeroen D]

Well, that does imply they will need to develop all devices specially for this system.

Devices is all about mass production to get the cost down. Will be interesting how they will do this in India. Big potential market, but every current (US based) GPS device known to man, works in India too. So why would you switch? You need to produce a lot of devices before you get to the price points of current GPS devices

Jeroen

[Jeroen Hoppenbrouwers]

Probably this price law is irrelevant for military and some professional equipment. Not depending on a foreign untrusted party may cost a lot of money, and many countries are willing to spend it.


Hoppie

[Jeroen D]

True, but it's also talking about civilian and consumer applications and then price becomes very relevant.

[Phil Bunch]

I don't understand how a military GPS system could be usable in a time of war or conflict - wouldn't it be trivial to jam the frequencies used?  Alternatively, use your own satellites to send out false data to all the smart bombs and other such things.  

Probably the false signal theory is made much harder by encryption and so forth, but jamming a weak radio signal would seem to be easy.  I must be missing something here.

[Phil Bunch]

I have never understood how the military is able to depend so heavily on GPS.  Wouldn't it be very easy to jam a weak radio signal like those emitted by GPS satellites?

[Jeroen Hoppenbrouwers]

Very easy to jam. I do it all day. "My" Iridium transceivers are next door to GPS and they easily blow off the complete GPS system. In a 737 that is a real problem and we have to install special filters to avoid it.

However this is the public system, not the subsystem meant for military use only, and the jamming effect rapidly decreases with distance between the Iridium antenna and the GPS antenna. On anything larger than a 737 the distance between antennas is large enough to not need filters.

GPS uses a signal type that is very much like noise, so it is also very resistant against jamming. You need to blanket a complete frequency band to stop GPS. But you can, with a sufficiently powerful noise generator (which will attract all anti-jammer missiles in the area).


Hoppie

[farrokh747]

this is the first ive heard of this....

Shiv's and mine tax rupees at work!

[Jeroen D]

Shiv's and mine tax rupees at work!

Too true. But if it's any consolation; GPS is funded by the American tax payer, GLONASs by the Russian taxpayer and CALILEO by the EC tax payers. (And the European Space Agency, but last I heard, most of their funding comes from EC tax payers as well)

Having lived, worked and paid tax in Europe, the US and now in India, I have been known to fund all.

I haven't really lived in Russia. Spent several weeks in Yakutsk, Siberia though. Did not pay tax, promise not to use GLONASS.

Jeroen

[Shiv Mathur]

Farrokh, you pay tax??
We've got to find you a smarter accountant ...