[time-nuts] GPSDO for my rubber duckie

cook michael michael.cook at sfr.fr
Tue Aug 2 10:03:21 UTC 2011

Le 02/08/2011 04:35, Michael Sokolov a écrit :

> Henry Hallam<henry at pericynthion.org>  wrote:
>> The parameters you'll want for conversion between MCAT and mean solar
>> time are given daily in the IERS bulletins:
>> http://hpiers.obspm.fr/eop-pc/products/bulletins/bulletins.html
> Yes, I know.
>> By making use of these you should be able to do much better than the
>> slightly inelegant leap second rubberization-over-10-seconds method
>> you had proposed.  Your rubber seconds should be smooth and
>> continuous, to the limit of the IERS measurement accuracy.
> But that would be quite a bit harder. :-)  I'll leave that as an exercise
> for Version 2.0; but I'll start with building 1.0 that does my simple
> rubberization.

I am also looking to create a  duck, quacking to MST.   I have a T'bolt 
for a tick which configures easily for GPS time rather than UTC, though 
other GPS receivers could do as well as I wasn't thinking of using the 
10MHz source. There are also receivers which provide GPS/UTC locked 
10KHz signals as well as 1PPS, ex.Jupiter T that could be another option 
for you. . My original idea was to use the IERS data to steer the system 
clock frequency to tick to MST. However, I did not want to have to 
script a weekly data transfer from the IERS bullitins to get dUT1, and 
was hoping that I could get it from the GPS data.  Unfortunately, it 
seems not to be avialable there, or at least I can't find it.  Various 
radio time transmissions do carry it, ex. MSF in my neck of the woods, 
and as I have lashed up an MSF receiver I may start testing with that, 
or more likely a  hybrid, just using the dUT1 data from MSF, as MSF 
spews legal time rather than TAI. However, even that would only be good  
if leap secs do not disappear  as the current data format only allows 
for a dUT1 of < +/-1 sec with a resolution of 0,1 sec.  As an aside, 
there does not appear to be anything in the American proposal to abandon 
leap seconds  to get a larger dUT1 corrections into the radio transmissions.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

More information about the time-nuts mailing list