[LEAPSECS] A consolidated approach.

[Finkleman, Dave]

I wisely avoided contributing the last few days' debate.  Ken
Seidelmann, John Seago, and I have been working to overcome the
deficiencies in the process used to formulate the "new" ITU-R
recommendation.  As we said in our paper last summer, the goals are to
assure that major stakeholders are included in consensus, to develop
normative guidance for accommodating leap seconds should they be
retained or work without them if they are deprecated, and to define in a
normative sense the different flavors of seconds, minutes, weeks, etc.
The guidance should include how to handle DUT greater than 0.9 seconds
and what the reasonable predictive time span should be for inserting
leap seconds.  These I have gleaned from your exchanges are your major
concerns and ideas.

How are we pursuing this?   We are using my authority within ISO.
Several ISO technical committees are affected:  ISO/TC154 (Processes,
data elements and documents in commerce, industry and administration,
ISO/TC12 Units and Measurement, and ISO TC37 Terminology as well as
JTC-1.    The terminology folks are already working on whether a time
scale unconnected with astronomical events should include the term
"universal."   

I bring this to your attention to solicit your participation in
resolving this long-standing issue.   There will be meetings in various
places, most often in Geneva.   

Changing the subject, the comments on geodetic references are very
relevant.  There is nothing like the leap second issue, but WGS-84 is
not used world-wide.  There are discrepancies in maps of Korea, for
instance.  WGS-84 is also out of date relative to the continuing
examination of the geopotential such as the GRACE mission.  

As you all know, Earth orientation and time are not independent.
Correlating EOP with real time observations in order to infer current
orbits precisely enough for assessing conjunctions among satellite is
very important.  



Dave Finkleman
Senior Scientist
Center for Space Standards and Innovation
Analytical Graphics, Inc.
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