[time-nuts] TIC resolution impact on GPSDO's performance

[Poul-Henning Kamp]

In message <458F5B82.8000501 at xtra.co.nz>, Dr Bruce Griffiths writes:

>> We know that the hardware PPS signal from gps is phasemodulated
>> with a +/- N ns signal which has a box distribution and upper
>> frequency limit of 2 Hz and which, subject to temperature stability
>> and hanging bridges, has no significant frequency components below
>> < 1/500s.
>>   
>How can this be true?
>The PPS output rate is 1Hz!
>Are you saying there is significant wideband noise on the 1 PPS output?
>Is that lower frequency limit 0.002Hz?

I'm talking about the negative sawtooth signal (as available in
the serial data stream) which is phase modulated onto the ideal
1PPS signal as received by the GPS receiver.

BTW, as you probably already guessed, 2 Hz should be read as .5 Hz
(It's the Nyquist limit thing).

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