Bugs: acis_process_events
A list of
bugs fixed in CIAO 3.4
is available.
Caveats
Aspect files must be arranged in chronological order
CONTENT keyword value is set to "EVT1"
(14 Feb 2007)
Bugs
Status bits in the input file are not reset when
reprocessing data
PHA_RO value in reprocessed files
(06 Mar 2007)
Stop-time for afterglow bad pixels
(06 Mar 2007)
Caveats
-
Aspect files must be arranged in chronological order
acis_process_events assumes that the aspect files
given in the acaofffile and alignmentfile
parameters are arranged in chronological order. If the
files are not in order, the tool will exit with an error.
If you have not altered the original filenames, a simple
"ls" will put them in order, as the time is listed
in the filename:
unix% pwd
/data/459/primary
unix% ls -1 pcad*
pcadf063874624N002_asol1.fits
pcadf063875522N002_asol1.fits
pcadf063902942N002_asol1.fits
Otherwise, get the value from the TSTART header
keyword:
unix% dmkeypar pcad_1.fits TSTART echo+
63875522.3455031
and put the files in chronological order.
-
CONTENT keyword value is set to "EVT1"
(14 Feb 2007)
acis_process_events always sets the CONTENT keyword
in the output file to "EVT1", regardless of whether the
input is an evt1.fits or evt2.fits file. (Note that there
are only specific cases in which an evt2 file may be used as
input to acis_process_events.)
Workaround:
While the CONTENT value will not negatively affect any
analysis downstream, users can change the value with
dmhedit if they so choose.
Bugs
-
Status bits in the input file are not reset when
reprocessing data
When acis_process_events is used to reprocess event
data, it does not unset status bits in the input data file.
For example, acis_process_events does not
recalculate the bad pixel status bits. If events have status
bits set in the input event file, then the values are
always copied to the same bits in the
column STATUS of the output file. If the badpixfile is
set to a value other than "NONE" (the default), then only
additional status bits can be set in the
output file. This limitation will be fixed in a future
release.
-
PHA_RO value in reprocessed files
(06 Mar 2007)
After the a file is reprocessed, the values of PHA_RO in
the output file are equal to the values of PHA (after the
CTI and tgain adjustments) in the original file. They
should be equal to the summed pulse height of the
original, unadjusted event island (PHAS).
Note that the PHA_RO values are not used by any CIAO tool
be default, so this should not affect subsequent analysis
steps.
-
Stop-time for afterglow bad pixels
(06 Mar 2007)
There is a bug where the stop-time of afterglow badpixels
is not being correctly used. Once marked as bad, the
afterglow badpixels are continued to be marked as bad (bit
16) until the end of the observation.
The following is a list of bugs that were fixed
in the CIAO 3.4
software release.
-
Pixels identified as having bias values that are too high or
too low are not recorded in the STATUS column of the event
file.
acis_process_events should set bit 4 in this
case. The bias value pixels are correctly recorded in
STATUS bit 16 of the bad pixel file (bpix1.fits).
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