> Now if only the US (and others) would get their act together and build out a b...

nayuki · 2025-01-11T17:32:52 1736616772

Encryption. For example, GPS's P(Y) code is encrypted and only for military use. https://en.wikipedia.org/wiki/Global_Positioning_System

dylan604 · 2025-01-11T18:26:36 1736619996

But that’s what the three letter agencies are supposed to do. Surely there’s a good guy back door to that encryption /s

throw0101a · 2025-01-11T17:25:45 1736616345

> What prevents other countries from using these other systems?

Nothing.

Nothing also prevents other countries from using China's BeiDou GNSS or their eLoran network.