[time-nuts] PN sequence generation using GPS

[Hal Murray]

albertson.chris at gmail.com said:
> I think GPS can help by using it to control the transmitter and to set the
> receiver frequencies but the "phase" of the frequency hop clock is
> determined by the time of flight of the signal, something a receiver can't
> know in advance 

Right.  But how big is the search space?

I think that depends on how fast you are hopping and the max distance you 
consider reasonable.

A mile is 5000 ns or 5 microsecond.  If you hop every ms there are 200 miles 
per slot.  If you hop every 100 ms there are 20,000 miles per slot.

If I pick a max distance of 1000 miles, that's 5 ms.

If you are off by half a slot, that will be 3dB down in the digital world.  
It would probably be pretty ugly in the audio world, but it would be easy to 
tune with a knob.


Actually, you can know the distance in advance for some games.  Suppose I'm 
going for the low power record from point X to point Y that are line of 
sight.  ...


-- 
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