Rasp Pi at +/- 1 us from GPS

Hal Murray hmurray at megapathdsl.net
Fri Dec 1 20:18:49 UTC 2017

> Should be simple to implement at the same time (that's what he said).

But at a foot per nanosecond for the speed of light, you have to get a pretty 
long cable before it becomes significant.


Light is actually slower than that in coax, but 1 is an easy number to 
remember and work with.  If you want more accuracy, I use the kilometer to 
mile conversion.  5 microseconds per mile in free space turns into 5 
microseconds per kilometer in coax or fiber.

That's for "good" coax, usually foam rather than solid dielectric.  Junk coax 
is slower but would probably kill the GPS signal if it was long enough to 
make timing corrections interesting.

These are my opinions.  I hate spam.

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