[time-nuts] GPS ADEV?
Tom Van Baak
tvb at LeapSecond.com
Sat Apr 7 07:08:25 EDT 2007
> Is there anyway that you can derive the same plot for an M12+ receiver
> with post facto (software) sawtooth correction?
> It should be marginally better than a CNS II. Hardware correction always
> adds some noise. Some of the Dallas programmable delay chips used in the
> CNS II are noisier than others.
Yes, that would be a good one to add to the plot. It should
reduce the jitter by 1 or 2 ns and so I suspect the software
corrected sawtooth line would be a few pixels below the
hardware corrected line on my plot.
Tom Clark & Rick Hambly showed a similar test at PTTI 2006:
Improving the Performance of Low Cost GPS Timing Receivers
You'll see the nice plot comparing h/w and s/w on page 15.
They also did a linearity test. Good paper; read it all.
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