Satellite television and radio require a subscription. Cell phones, which use satellites, require a subscription. Why doesn’t GPS require a subscription?
Uncle Sam is doing a public good, says wikipedia.
GPS was developed by the US Military for their use. They just happen to let other people tap into the microwave signals.
Don’t give them any ideas! /s
Think of how your taxed dollars made this possible.
Perhaps it’s similar to the atomic clock signal broadcast out of Colorado – the government does it because it needs to for whatever reason. It allows the public to also tap into and use the info, because it doesn’t degrade the signal or hurt anyone to do it that way.
It’s not free, strictly speaking: you’re paying for it out of your Federal taxes; the GPS system was implemented and is maintained by the US government. Satellite radio and cable TV, on the other hand, are private enterprises.
One thing to note is that there are two signals. There’s a highly accurate, encrypted signal which the military uses. The uncoded civilian signal used to be less accurate, with random errors added or some such. At some point they made it as accurate as the other, but they could degrade it again, typically if there was a war on.
Yes, well, clever civilians broke the code very quickly and I have even read that during Iraq I, the army bought civilian decoders because, typically I guess, the army had not bought enough for the troops.
They do?
I thought they just used land-based towers, which transmit to an area around the tower called a “cell” – thus the name.
While there are specialized satellite cell phones usable world-wide, they are rare, specialized ones. I think the majority of normal cell phones just use land-based cell towers.
Sounds like OP was referring to satellite phones, which although quite expensive are still available if you dig long and hard enough.
Keep in mind though that people can use GPS worldwide, whether they are American citizens and pay our taxes or not. The price is actually fairly substantial too, something like 3/4 of a billion/year in maintenance.
Although Europeans needn’t worry about not contributing, since EU countries are building (with international cooperation from the United States) a similar system called the Galileo positioning system.
Also, I believe the EU system will actually have a paid version available to commercial users in addition to the free one available to anyone with a Galileo receiver. Although it is hard to say how it will all ultimately pan out since the EU has had some bureaucratic and budgetary problems with the system since they started on it.
It was in the long-term strategic interest of the US Govt to allow other nations to use their GPS system.
The USA currently has a monopoly on GPS - China and Russia have a limited version, but NAVSTAR is the only full-coverage system out there.
If they refused to allow anyone else to use it, the EU and others would probably have launched their own system by now. Of course, that removes America’s edge on the battlefield in having 100% control of the GPS technology that most modern armies rely on.
The $750m isn’t actually that much when balanced against the strategic benefit of having the keys to the GPS toybox.
I believe the USA has lobbied pretty hard to prevent the EU developing the Gallileo system - it’s a fairly major political statement.
The biggest difference is that a cell phone both transmits and receives, therefore it can be ‘tracked’ or determination of use can be made. A gps receiver can only receive signals and interpret them to determine location. They do not transmit at all, so there would be no way to determine use.
In the beginning the US pressured strongly against the Galileo system, but has since come around. This was primarily because of a June 2004 agreement between the EU and the U.S. that would set up the Galileo system in such a way that the U.S. can block Galileo signals on the battlefield just like they can block GPS signals now for tactical advantage (the agreement also gives the EU member states the ability to block GPS data too, so they can enjoy the same tactical advantage.)
Free civilian access to the GPS signal was guaranteed after the Soviet shootdown of KAL 007:
Thanks for all your answers, guys. I told my folks - who recently bought a GPS receiver for the car - and they were quite impressed with your knowledge 
Was it broken? I thought that as a policy selective availability was turned off in 2000.
He said Iraq I, IOW, Desert Storm. 1990-91.
He said that the military purchased civilian GPS units. I can believe that military would have a lot of use for units with poorer accuracy if more precise units were not available.
I have never heard anything about the selective availability encryption being broken. A quick google turns up nothing indicating that it was broken.
Perhaps it wasn’t, and perhaps they did. I was just making the point that the 2000 switch off date isn’t relevant if he was taking about Desert Storm.