We recommend that all VLBA users update the predicted or first-look
Earth Orientation Parameters used by the VLBA correlator to the final
values available from USNO. This is done in AIPS with the task CLCOR,
_or_ with the procedure VLBAEOPS, which invokes CLCOR.
The recent leap second unearthed a bug in CLCOR, now fixed. Users should
update their installation of AIPS with the midnight job.
Help is available at:
or by email to email@example.com.
The bug was that CLCOR, run on data observed after 1 Jan2006, effectively
used the wrong value for the leap second. The symptom is that the "USNO"
and "Used by Correlator" values, as reported by CLCOR at execution,
differed by 1 second. They should differ by a few milliseconds at most.
CLCOR run on data prior to 01 Jan2006 works correctly when TAI-UTC is
32 seconds; it is now 33.
Friday, 26-Sep-2008 12:16:52 MDT