will GPS always be free? - Page 2

tdevil · 09-30-2004, 03:41 AM

heard too many stories about misguided bombs/missles although those werent probably gps guided.

hrmmm, military gps.... it couldnt be that hard to crack could it?

/runs as men with M16s pop out of black SUVs that just pulled up

djmickyg · 09-30-2004, 04:20 AM

thanks all you americans for this service.

stevieg · 09-30-2004, 04:25 AM

The european enion is introducing 'Gallilao' or something similar as far as I know, which is supposedly compatible with GPS, more accurate and intended to prevent the americans from holding a monopoly over GPS. I'm not sure when it's supopsed to go live, but it too will be free to use.

Nufis · 09-30-2004, 04:30 AM

I really do not know if it adds to what Skoprion said or is a separate story, but there are so called 'differential' GPS receivers (which have nothing to do with the old, navi's controlled, differential ground correction signal implementation) but just incorporates two GPS receivers into single unit, and are capable of accuracy of several inches. And, what's most surprising, they are commercial, not to say - they are not cheap...

DeltaFX · 09-30-2004, 12:39 PM

Gallileo will start in 4-5 years . Technically, US gov descrambled the civilian part of the gps technologiy ( 100 feet accuracy before 2000) when european countries finally decided to build the gallileo. How strange....

Gps won't die because of radar limitations. The FAA's been experimenting ADS-B technology in Alaska since 2001, and Australia does the same in Queensland sinc 2002. Radars can't cover every square inches, they're limited to roughly few hundred miles. With ADS-B, a plane transmits its position, speed, identity to ground stations and to other planes.

gadget · 09-30-2004, 01:26 PM

Quote: Originally Posted by tdevil

hrmmm, military gps.... it couldnt be that hard to crack could it?

I know a bit about it, and YES it can be pretty hard to crack. However back in the first gulf war anyone with a GPS noticed the error was turned off about 12 hours before the war started. (If you called they asked you to NOT SAY ANYTHING as a matter of national security) The USA didn't want their cryptos to end up in the wrong hands and get reverse engineered. They knew the USA was the only ones with GPS guided bombs, so they shut off the error for a week or so. Told the Army to leave the crypto gear at home as they would have accurate GPS when they needed it.

Yes I think in 2001 the error was reduced by about a factor of 10. Yes there are some better systems out there and differental GPS, but do you REALLY need that to find your way around town?

I believe the gov has until 2007 to do whatever it wants and can shut it down at any time they want to. Chances are they will NOT. After that I believe it will go into free public use and the gov cannot shut it off. I don't know the details of that, but I do know that FAA is NOT ready to move to 100% GPS based systems and keep backup systems in place at least for now.