So why don't planes do that that? You need 24 bits for 3 meter GPS accuracy (times 2). Add some extra for altitude and airplane ID (or does a unique ID come built in?) So maybe 80 bits in total.
This would be nothing for an airplane - $0.40 per hour? Why don't they do this already?
Actually rules made by the FAA do pretty much affect every nation. Many nations do not have their own version of the FAA and just rely on the US.
But it's even easier than that: Just make all US owned airlines require it, and any flight landing in the US. Phase it in, etc, to give time to upgrade, but it's certainly possible.
I believe that Rolls-Royce doesn't sell it's engines; it leases them instead. So engine telemetry data from many airlines is transmitted to the engine's owner, which happens to be a central organisation.
(Of course, it is a business, rather than branch of a government, and not the only manufacturer of jet engines).
Care to link to it? I didn't find anything by "Stross".
My numbers were $0.40 per hour, plus a few hundred for the equipment (it's available off the shelf, don't need anything custom). Don't know how much installation would be, but certainly not millions.
If the system sends signals EXACTLY every 30 minutes, then a very careful reconstruction of signal running times (combined of course with the positions of the recieving antennae and the EXACT times the signals were recieved) can reveal information about the heading and position.
That's a good point, if the timestamps have the necessary precision and their clock drift info hasn't been lost by a resync since then. I'd guess that since exact time isn't crucial to the purpose of these messages, though, that they probably don't have very high precision timestamps. :-(
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