ROSAT CALDB UPDATE

[Mike Corcoran <corcoran@barnegat.gsfc.nasa.gov>]

The aluminum K gain maps in the ROSAT Calibration Database have been
updated (update 19990709).  These data files provide maps of the PSPC
spatial gain variations for a series of time intervals covering the
Cal/PV and nominal GO observation phases.  They are derived from the
onboard Al Kalpha calibration data.  Data from the range of ROSAT days
listed in the file names are binned in overlapping spatial bins and the
pulse-height distributions fit with the detector response matrix.  The
fitted values for the means of the distributions are used to create the
gain maps.  These gain maps are then used by the Ftool PCTCOR to correct 
individual observations for these variations.


A new tar file of the ROSAT CALDB is available at:

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/goodfiles_rosat_pspc.tar.Z

Users with the ROSAT CALDB already installed can simply replace their
current alk_gainmaps directory (which should be found in
$CALDB/data/rosat/pspc/bcf/alk_gainmaps)

with 

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/bcf/alk_gainmaps/

and copy 

ftp://legacy.gsfc.nasa.gov/caldb/data/rosat/pspc/caldb.indx

to $CALDB/data/rosat/pspc/caldb.indx

Please address any problems to caldbhelp@olegacy.gsfc.nasa.gov

cheers

Mike

-- 

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Dr. Michael F. Corcoran
High Energy Astrophysics Science Archive Research Center
Code 660.2
Goddard Space Flight Center
Greenbelt, MD 20771
corcoran@barnegat.gsfc.nasa.gov
LHEAVX::CORCORAN
http://lheawww.gsfc.nasa.gov/users/corcoran/bio.html
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