Subject: SUMER Local-Gain Correction in SolarSoft


Dear colleagues,

the local-gain correction programme of SUMER has been used since early 1997
without any problem. Now, with the ageing detectors, Udo Schuehle and
Luca Teriaca experienced some difficulties in the sense that negative
corrected counting rates appeared at very high observed counting rates.
Since they are, in most cases, caused by detector effects and
therefore unphysical, and correction data are only available
up to 300 counts per pixel and second, the modified programme just limits
the counting rate to this value. A warning will be issued and a detailed
check has to be performed by the user.

The new programme replaces the old one in SolarSoft. Old corrections
with counting rates up to 300 will not be affected by this modification.

With best regards,

Klaus Wilhelm

16. August 2005