Screening, Combining and the Bad Pixels Map

Once you have modified the screening parameters (except for pulse-height), you need to regenerate the BPM file with cf_bad_pixels. Since cf_bad_pixels doesn't operate on a combined file, if you use CF_EDIT to simultaneously combine and screen a file, you won't be able to generate a BPM file for the output.

If you really care about the bad-pixels (for example if there is a pothole in a spectral feature you are interested in) , here is the way to do it. Let us assume, we have a stack of exposures M1010101*1attagfidf.fit that we want to combine, selecting only the night-time events. Run idf_screen or CF_EDIT on each exposures selecting only the night-time events. The result is a stack of IDF files M1010101*1a_night_ttagfidf.fit. On each of these files, run cf_bad_pixels. Combine the screened IDF files with idf_combine or CF_EDIT. Run bpm_combine on the combined IDF file.

Here is a shell script that does all of this:

#!/bin/sh
#
# Takes one argument : observation rootname (example: M1010101)
# Selects the night-time events only
# Combines all the IDF files
# Creates the associated BPM file
# This for each segment: 1a, 1b, 2a and 2b
#

rm *ttagfbpm.fit
rm *_night_ttagfidf.fit


for seg in "1a" "1b" "2a" "2b"
do
    str=${1}[0-8]??${seg}ttagfidf.fit
    exposures=`ls $str`
    for expo in $exposures
    do
        exposcreen=`echo $expo | sed -e 's/ttag/_night_ttag/g`
        idf_screen $expo $exposcreen DAY GOOD
        cf_bad_pixels $exposcreen
    done
    str2=${1}[0-8]??${seg}_night_ttagfidf.fit
    idf_combine -c ${1}all${seg}_night_ttagfidf.fit $str2
    bpm_combine ${1}all${seg}_night_ttagfbpm.fit \
                ${1}all${seg}_night_ttagfidf.fit
done   

exit 0