[LEAPSECS] NIST UT1 NTP server results

[mike at lumieresimaginaire.com]

On 22.07.2016 22:47, John Hawkinson wrote:

> "Mike" <mike at lumieresimaginaire.com> wrote on Fri, 22 Jul 2016
> at 22:21:08 +0200 in 
> <bec8a6a992cdbd21bb47efe68a5797d8 at lumieresimaginaire.com>:
> 
>> You will also note from the NIST document and the NIST time server
>> address links, that the UT1 NTP service will not respond to
>> unregistered requests.  NIST may or may not have opened the box
>> deliberately. I don't know, but if you wish to use the service
>> please at least contact Judah before doing so. It would be a shame
>> to have it going deaf.
> 
> On June 28, Judah Levine and NIST announced via the IERS Message list
> that NIST's UT1 ntp-based time service would be open access beginning
> in July 2016. Announcement reproduced below.
> 
> I found your email fairly confusing.

  Thanks for that info. It didn't get to their page yet. What was 
confusing you John.

> 
> --jhawk at mit.edu
> John Hawkinson
> 
> Message-ID: 
> <25948628.481467094028650.JavaMail.cmadmin at gsb50ml1.ffm.web>
> Date: Tue, 28 Jun 2016 08:07:08 +0200
> From: <central_bureau at iers.org>
> To: <messages at iers.org>
> Subject: IERS Message No. 303: NIST UT1 Internet Time Service
> 
> ************************************************************************
> IERS Message No. 303                                       June 28, 
> 2016
> ************************************************************************
> 
> NIST UT1 Internet Time Service
> 
> The Time and Frequency Division of NIST operates an Internet time 
> server
> that transmits UT1 time in the Network Time Protocol (NTP) format. The
> server is synchronized to UTC(NIST) by a direct connection to a local
> cesium standard. The offset between UT1 and UTC is added to the reply 
> to
> a query for the time. The time difference between UT1 and UTC is
> obtained from IERS Bulletin A, and the value used by the time server
> changes every day at 0 h UTC. The time step at 0 h UTC is generally
> about 1-2 ms. This time step is generally too small to be detected by
> most users.
> 
> The accuracy of the time at the server is approximately 4 ms, and is
> determined by the uncertainty in the prediction of the difference
> UT1-UTC in the IERS Bulletin A. The accuracy of the time received by a
> user will usually be limited by the stability of the network delay from
> the user's system to the time server. The overall accuracy of the time
> as received by a user will generally be better than 10 ms, and will
> often be significantly better than this value.
> 
> The name of the server is ut1-time.colorado.edu and its address is
> 128.138.140.50. The ut1 time service is currently restricted to users
> who register with NIST (by e-mail to Judah.levine [at] nist.gov), but 
> it
> will be converted to open-access in July, 2016.
> 
> The NIST is the US National Institute of Standards and Technology
> (http://www.nist.gov/).
> 
> Questions or comments to Judah.Levine [at] nist.gov
> 
> ************************************************************************
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