re: #91 Nojay UK

The restrictions are still in place for over-the-counter GPS chips. I don’t know if the restrictions apply for any GPS systems that use the European Galileo satellites since that system is primarily commercial and not military like all the others (GPS, GLONASS, Beidou).

The knowledge base exists to make a GPS decoder that would actually work at all speeds and altitudes since the details of how they work are all known. I’m pretty sure I’ve seen mention of at least one open-source project to do just that. It’s not a simple single-chip solution that costs five bucks quantity 100,000 though, FPGAs may be involved.

At least theoretically, you could make a SATNAV receiver chip that bypasses these restrictions, because it’s all in the receiver chip. The satellites have no idea you exist, of course.

For Galileo, there is an encrypted mode like GPS has and, presumably, GLONASS (Russian) and Beidou (Chinese). It’s not called a military mode, but does require a formal agreement between national governments and the EU to obtain access to the hardware and encryption keys. In all these cases, they’re not really any more accurate than the open protocols any more, but have anti-jam features and wouldn’t be disabled during wartime.

The big row over Galileo was because of Brexit. The UK was the main developer of Galileo, and guess what, now they’re not in the EU anymore, so are a third nation and have to apply for access like all the rest of the non-EU schlubs. So Whitehall got pissed off and started to talk about a totally new UK SATNAV constellation, until they got laughed at enough and dropped the idea.