[LEAPSECS] LEAPSECS Digest, Vol 45, Issue 1

Rob Seaman seaman at noao.edu
Thu Sep 2 15:21:14 EDT 2010

On Sep 2, 2010, at 11:26 AM, Ian Batten wrote:

> Could you clarify that? DUT1 is surely produced by IERS, who aren't accountable to the ITU, and propagated by (as examples) WWVB and MSF, which are accountable via NIST to the US government and via NPL to the UK government. I assume the other nationally operated time sources have similar governance. I'm not sure how the ITU could stop MSF from reporting DUT1.

Could anybody clarify this alphabet soup? :-)

The current "definition of UTC" in ITU-R TF.460 (blah blah blah) includes both a description of leap seconds and a mechanism for DUT1. The proposed redefinition does not.

A coherent engineering plan for a system with worldwide implications would be much more complete and formalized and would represent a consensus vision worked out in advance. The result of such a vote should be evident and noncontroversial to all before the vote is taken.

> But if you drop leap seconds in UTC, DUT1 relative to "new UTC" will rapidly exceed 0.9s, which breaks everything that consumes those signals and, for example, breaks astro-navigation unless somehow the format is fixed to allow for |DUT1|>0.9.

Indeed. And one suspects that the "non-opinions" of the International Astronomical Union and the American Astronomical Society that are being used to prop up this process will rapidly change when the resulting remediation expense becomes evident to the broader astronomical community.

Due diligence has not been satisfied.


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