Re: [LEAPSECS] ideas for new UTC rules

From: Steve Allen <sla_at_UCOLICK.ORG>
Date: Fri, 14 Apr 2006 09:59:56 -0700

On Fri 2006-04-14T09:43:45 +0200, Poul-Henning Kamp hath writ:
> If you put a provisional table of leapseconds into your products and
> reality turns out differently, who is liable for the discrepancies ?

It's a good question. My immediate response is that my notions are
also part of the
        "Full Time-Scale-Aware Lawyer Employment act of {YA}"

> If you add 10 more leapsecond opportunities per year you will
> decrease reliability of the provisional table, compared to if
> there is only two opportunities per year.

The motivation is that allowing ten more per year requires action on
the part of all systems to upgrade anything which now believes only
June and December (and they get ten years of notice to do so). More
importantly, it allows the IERS to react better to any surprises in
decadal fluctuations of LOD.

I should add one more culturally-derived defense of a possible problem.
The DUT1 signals which only allow as much as 0.7 or 0.8 s of
magnitude. What sorts of applications will be affected by that?

Paraphrasing Westly in the fireswamps of The Princess Bride
        DUT1 signals? I don't think they exist.
Well, I don't think anyone uses them. If there are still many
applications for DUT1 signals, most likely they are for sextant-style
navigation. If the leap seconds are being predicted five years in
advance then the annually published navigation almnacs can incorporate
projections which are as good as the broadcast signals.

Steve Allen                 <>                WGS-84 (GPS)
UCO/Lick Observatory        Natural Sciences II, Room 165    Lat  +36.99858
University of California    Voice: +1 831 459 3046           Lng -122.06014
Santa Cruz, CA 95064     Hgt +250 m
Received on Fri Apr 14 2006 - 10:00:14 PDT

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