the GPS impending leap second bit

From: Steve Allen <sla_at_UCOLICK.ORG>
Date: Thu, 19 Jan 2006 10:53:48 -0800

On Thu 2006-01-19T18:30:02 +0000, Markus Kuhn hath writ:
> GPS sends out announcements within days after IERS does, which is
> excellent service.

Yes, and no, for some notes from the NTP newsgroup imply that the
setting of the GPS impending leap bit caused some GPS units to insert
leap seconds every day at 0h UT.

Furthermore, in
http://www.uscg.mil/hq/g-m/moa/docs/Saab505.pdf
we see that the Saab AIS units introduced the leap second immediately
and needed a firmware update to fix the condition.

As Andreas Bauch said, "Schlampig programmierte Software".

> I fully agree that leap seconds should be announced as early as
> possible, and I think that anything less than a month is undesireable.

That would mean you can live with the current specification in TF.460
for around another 1000 years. After that, the impending leap bit
will almost always be on and almost every month the week and
second-of-week fields will simply increment to indicate next leap at
the end of the current calendar month.

--
Steve Allen                 <sla_at_ucolick.org>                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        http://www.ucolick.org/~sla/     Hgt +250 m
Received on Thu Jan 19 2006 - 10:54:09 PST

This archive was generated by hypermail 2.3.0 : Sat Sep 04 2010 - 09:44:55 PDT