[time-nuts] new WWVB BPSK dev board

[Poul-Henning Kamp]

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In message <6718818b-5243-8ad1-ddbd-6115fcdb6c29 at earthlink.net>, jimlux writes:

>On 12/4/18 9:00 AM, Tim Shoppa wrote:
>> Because of the Q of WWVB's transmit antenna (at least 300 by my back of the
>> envelope estimates), I don't think we could ever claim a WWVB PPS edge
>> sharper than 5 milliseconds and that might be optimistic.
>
>Sure you can.. you do a matched filter to the waveform, so you're not 
>just looking at a single zero crossing or cycle.  Getting fraction of a 
>degree phase accuracy from a strong signal is entirely possible.

See also:  Loran-C ?

And with the new phase modulation, you can do get down in low
microseconds at tau=1, but the atmosphere will ruin longer taus.

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