-
You can literally see the packets of data that the receiver receives. You, me, the guy who runs Mamnick, anybody who owns a receiver and a computer, can see the data.
So unless each receiver is filtering out confidential information, which means every single device manufacturer is in on the system, that's just not possible.
The point of SA is that every GPS receiver is receiving information that is partially obscured. The lower order bits of the timestamps from the satellites (which form the basis of the trilateration) are encrypted, so they are effectively random noise. If you know the encryption key (which changes daily in some implementations) then you get the accurate timestamps and therefore the most accurate location. If you can't decrypt the lower order bits of the timestamps then they're random noise which leads to accuracies of 50m+ when used.
Anyone can see the data, sure, but only those with the encryption key(s) get the completely accurate data.
the military is dedicated to the development and deployment of regional denial capabilities in lieu of global degradation through SA
The signals from the satellites are piss weak. It would be easy for the EU to pump out conflicting signals towards the UK which are enough to introduce a ~50m inaccuracy in GPS measurements (akin to what SA would do globally). And there would be close to fuck all that the UK could do about it apart from whine. This is what the US mean by "regional denial capabilities"; it's not jamming, but spoofing.
Anyway, it's simply not a problem as I don't think any UK Sat Navs are designed to run solely on Galileo. If we get to the point that Russia turn off access to GLONASS and the US restrict access to GPS (i.e. what was NAVSTAR) and we can't get access to India's system, or China's, or Japan's, then we are already properly in the shit. We'll be long on the way towards mutual assured destruction by that point so being able to direct an Uber to your front door will be the least of your problems.
You are reading a single comment by @Greenbank and its replies.
Click here to read the full conversation.
Greenbank
You can literally see the packets of data that the receiver receives. You, me, the guy who runs Mamnick, anybody who owns a receiver and a computer, can see the data.
So unless each receiver is filtering out confidential information, which means every single device manufacturer is in on the system, that's just not possible.