[time-nuts] Capturing NMEA and TICC timestamp data in time-correlated way?

[Andrew Kohlsmith (mailing lists account)]

> On Sep 14, 2019, at 5:20 PM, Mark Sims <holrum at hotmail.com> wrote:
> Lady Heather should do the job.  It supports using a GPS device as the main input device and a TICC/counter as an auxiliary input device (/ei=  command line option).   Writing a .xml format log file will have all the data.  On a TICC you should connect chA to the 1PPS signal (and optionally the divided down 10 MHz to chB.
> 
> The next version of Lady Heather has a way to write a file with sawtooth corrected counter measurements.  Note that there are 12 ways to sawtooth correct the PPS measurement.  Only one way will work for a given combination of GPS/counter:
>   add/subtract receiver sawtooth value
>   apply the sawtooth correction to the previous/current/next counter reading
>   apply the correction to the PPS reading or the PPS phase

I’m interested in learning more about how this sawtooth comes about, how it’s predicted (so you can correct for it) and so on. Are there approachable documents/sites/source with this information? I’m still a time-nuts newb.

-A.