If you're talking about software and hardware implementation at the user level, well, you're absolutely right, no argument. There are some very clever proprietary algorithms in use even now to get more & more accuracy out of the basic signal.
I think it's helpful that the GPS space and control segments are operated by the USA for national security purposes. The technology is owned by a very public-spirited, dare I say generous, govt. The next iteration of civil technology is likely to use multiple frequencies to generate a fix currently only available to P (military) code users, so will continue to be free to all.
Last edited by Oktas8; 24th Dec 2012 at 01:23.