Date: Mon, 12 Dec 2005

The IRS LH module underwent a bias change pre-IRS 25 to reduce the
number of rogue pixels. If your data were taken in IRS Campaigns 25 or
26 i.e. between Oct 6 and Nov 23, 2005, most (all modules except LH)
have been processed with the S13 pipeline and are available in the
archive. The calibration files that you will get from the archive for
all modules except LH are correct. For LH, the calibration files are
being re-derived and will be ready in the near future at which point
your LH data from these campaigns will be available from the archive.
Data from campaigns before Campaign 25 will be reprocessed with the S13
pipeline within a month.

SPICE has not yet been updated to handle S13 data but will be able to do
so within a month. As a result SPICE does not have the S13 cal files. If
you plan to do custom data reduction with SPICE on your S13 data, please
be sure to point SPICE to the cal subdirectory that you get when you
unzip your files from the archive.