3 ms·
Probably, although if you were paranoid enough (or required by regulation), you could airgap the TVs and give them information through a normal GPS system (minu
by gizmo686 12y ago
Probably, although if you were paranoid enough (or required by regulation), you could airgap the TVs and give them information through a normal GPS system (minus the artificial altitude restriction), or have a hardware unidirectional data path. More reasonably, you could consider the TVs part of the flight system network (with many of the same protections to prevent someone from physically opening one and hacking), and still have an airgapped wifi network.
- StavrosK 12y agoWhat altitude restriction? My phones' GPS works fine in flight, I use it a lot to check speed and altitude.
- klodolph 12y agoYeah, the altitude restrictions don't really apply to commercial flight. You can conduct a test yourself, you just need to get a little higher and travel a little faster than your typical 757. Try attaching your cell phone to a rocket travelling over 1200 mph or above 60,000 feet, you'll find that your GPS unit basically shuts down. That's not to say that your GPS hardware is incapable of operating under those parameters, it's just designed to shut down so it can't be used to guide ICBMs. Commercial airplanes typically operate at half the altitude and speed which would trigger the condition.
- MichaelApproved 12y agoDon't both speed and altitude trigger the block? The gps must be over a certain altitude AND be going faster than a certain speed.
- callesgg 12y agoIt is one or the other.
- proexploit 12y agoIIRC, the legal requirement is to shut down with both conditions are present, some GPS manufacturers simply found it easier to implement each restriction separately.
- michaelt 12y agoAccording to [1] some manufacturers apply this limit when both speed and altitude limits are reached, while other manufacturers disable tracking when only a single limit is reached. The limits are 1,200 mph speed and 18,000 m altitude. Google tells me a 747's limits are around 615 mph and 14,000 m; Concorde's limits were closer to 1,350 mph and 18,300 m. Still, I'm sure if you're making an airliner you can get access to GPS receivers that will work even at maximum speed and altitude! [1] http://en.wikipedia.org/w/index.php?title=CoCom&oldid=608893426#Legacy http://en.wikipedia.org/w/index.php?title=CoCom&oldid=608893...
- kalleboo 12y agoDo the limitations also apply to GLONASS which is now in all modern devices?