Steve Allen wrote on 2003-01-29 22:19 UTC:
> Aside from GLONASS, those who wish to abolish leap seconds
> have not concreately identified the systems which don't like leaps.
Even for GLONASS, the alleged system-inherent leap-second problems seems
extremely badly documented and the entire story is likely to be just an
urban legend.
All I could find are a few second-hand non-technical reports/rumours
that suggest more that certain early GLONASS receivers might have had
software bugs that caused a loss of tracking for a few minutes after a
leap second. Well, such bugs can/ should get fixed. Or is there clear
evidence (a knowledgeable document with all the technical details) that
GLONASS actually *has* to take the broadcasting satellites offline
merely to do the leap second adjustement? Where? Sounds very odd and
unbelievable to me.
In fact GLONASS operational bulletins such as
051-970619
NOTICE ADVISORY TO GLONASS USERS (NAGU) 051-970619
SUBJ:UTC LEAP SECOND CORRECTION 1.07/0300 MT
1.CONDITION: ACCORDING TO IERS BULLETIN C-13 FROM 30.06 TO 01.07 AT 0000 UTC
THERE WILL BE LEAP SECOND CORRECTION OF ALL UTC TRANSFER
FACILITIES INCLUDING GLONASS.
TIME MARK SIGNALS WILL BE TRANSMITTED AS FOLLOWS:
30.06.97/23 H 59 MIN 59 S (UTC)
30.06.97/23 H 59 MIN 60 S (UTC)
01.07.97/00 H 00 MIN 00 S (UTC)
2.POC:CSIC RSF AT +7-095-333-81-33
052-970619
NOTICE ADVISORY TO GLONASS USERS (NAGU) 052-970619
SUBJ:FORECAST OUTAGE FOR ALL GLONASS SPACECRAFT 01.07/0259-02.07/0259
1.CONDITION: ALL GLONASS SPACECRAFT ARE SCHEDULED TO BE UNUSABLE
SINCE 01.07/0259 UNTIL 02.07/0259 MT (UTC+0300)DUE TO
PLANNED GLONASS TIME CORRECTION (NOTE: THIS IS NOT
CONNECTED WITH LEAP SECOND CORRECTION)
2.USERS ARE REMINDED TO DO NOT PLAN ANY OBSERVATIONS FOR THIS PERIOD
3.POC:CSIC RSF AT +7-095-333-81-33
on
http://www.rssi.ru/SFCSIC/1997.htm
claim even explicitely that the announced satellite down-time for the
entire day 1997-06-31 23:59Z to 1997-07-01 23:59Z was not connected with
a leap second correction, even though it admittedly coincides with it.
Perhaps they just need to take the entire system offline from time to
time, and sometimes let these servicing periods coincide with leap
seconds? In fact there was no such announced downtime at the next leap
second at the end of 1998 <
http://www.rssi.ru/SFCSIC/1998.html>!
Summary: The leap second problems of GLONASS sound to me very
much like an urban legend or a popular missunderstanding.
More on GLONASS:
http://www.rssi.ru/SFCSIC/english.html
Markus
--
Markus Kuhn, Computer Lab, Univ of Cambridge, GB
http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__
Received on Thu Jan 30 2003 - 06:42:27 PST