clements@bbn.com (Bob Clements) (12/06/90)
I believe it has been officially leaked to this group that there will be a leap second at the end of this month. Does anyone know what the DUT1 value will be immediately thereafter? (I.e., is it shifting by 1.0, 0.9 or 1.1 seconds?) Thanks, Bob Clements, K1BC, clements@bbn.com
Mills@udel.edu (12/07/90)
Bob, Whattaya mean "official?" I copied the verbatim text of the USNO notice to this group upon receipt. I don't think you can answer the question until you know the DUT1 immediately preceeding the leap, and that depends on the schedule of the cocktail parties in Paris on New Year Eve. The above scatology is not my invention, but I refuse to disclose the source. A wee bird has whispered in my ear that Spectracom may be ready for testing a new receiver in February. I chirped back that it is too bad this schedule could not be moved up so that the leap might even be seen to have been lept, since the new receiver allegedly includes provision for that obscurity. Dave
clements@BBN.COM (12/07/90)
.. I don't think you can answer .. the question until you know the DUT1 immediately preceeding the .. leap, and that depends on the schedule of the cocktail parties .. in Paris on New Year Eve. .. Dave I think DUT1 changes on month boundaries. When I was last at WWVH there was a note on the bullboard specifying what the DUT1 would change to at the end of the then-current month. So they probably know it now, its being December and all that. And I'm pretty sure it won't change between now and then. My intent (in case the between-the-lines writing was muddy) is to make a two-track audio tape at the time of Leap with the broadcast timecode from 15 MHz on one channel and my prototype TCG's output on the other. I'd like to know what the DUT1 should change to in order to get my code right. Of course, having seen the hardware, I know they need to manually crank a thumbwheel switch to change what they send. Mine will change it automagically. In the past, the transmitted DUT1 typically has changed a few minutes after the leap. So for those few minutes it has been _WAY_ off, having not moved from -.5 to +.5 (or whatever) with the insertion of the leap. /Rcc
Mills@udel.edu (12/08/90)
Philip, Unless you are a navigator, forget the DUT1. Official time is UTC, which doth not include the DUT1. Dave
philip@beeblebrox.dle.dg.com (Philip Gladstone) (12/08/90)
In article <61390@bbn.BBN.COM> clements@bbn.com (Bob Clements) writes:
clements> I believe it has been officially leaked to this group that there
clements> will be a leap second at the end of this month. Does anyone know
clements> what the DUT1 value will be immediately thereafter? (I.e., is it
clements> shifting by 1.0, 0.9 or 1.1 seconds?)
I was about to answer a different question when I realised what you
asked. I don't know the answer to your question.
The answer to
'What will the DUT1 offset be after the correction takes place?' is
I am not sure. The current offset is -0.3 seconds so it seems
suprising that a leap second is due anyway. How do I know? It so
happens that the timecode I get from my stratum 1 server tells me:
901207 2027 U -3 660601619.999728
yymmdd hhss Z DUT1 Unix time of the 00 second.
Thus my system was out byt 300us (according to this sample).
Philip
--
Philip Gladstone Dev Lab Europe, Data General, Cambridge, UK
Listen three eyes, don't you try and outweird me, I get
stranger things that you free with my breakfast cereal.