GPS Satellite Question

[Binnie]

I don't think they can restrict access to the sats

my understanding is they are either on or off.

your satnav doesn't talk to the sattelites, its basically a complicated signal strength meter, calculating coords by signal strength and either displaying data as coords, or displaying a point on a map.

Its a receiver only.

unless the US gov have a way to "switch channels" so only thier gear works, i think all GPS will work after an event, unless as SD says, its a major EMP event.