[time-nuts] How does sawtooth compensation work?

Hal Murray hmurray at megapathdsl.net
Tue Jul 19 00:41:08 EDT 2016

nsayer at kfu.com said:
> Yes, that’s true. Given the facilities I have available with the present
> hardware, I don’t believe I have much choice. I am not confident that I
> could tell the difference between noise in the phase detection system and
> PPS jitter variations that small. If the PA6H receiver gave sawtooth
> corrections, I’d be able to do better. 

It would be interesting to look at the data to see if you can find the sort 
of pattern that a sawtooth correction would help and where a hanging bridge 
might cause confusion.

If the bridge isn't hanging, the data samples should be spread over a range 
that is the clock period of the GPS unit.  Round that up to 100 ns.  I doubt 
if you will see that with a PC.

On the other hand, you can get the same sort of pattern with a PPS over USB.  
That would be a ms wide and easy for a PC to get time stamps much finer 
grained than that.

These are my opinions.  I hate spam.

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