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Data Reduction of VLT-UVES

The end goal will be to run UVES_headsort to correctly setup the reduction scripts to reduce science exposures. Let’s look at reducing the VLT-UVES science exposures for a single object: vesta.

Start with a bunch of raw UVES data files in a folder (let’s call it raw) that are named things like:

In this mess of files, there exist all manner of calibration and science exposures for the spectrograph in different settings. It’s a mess, so the first order of business is to organize this into something that can be used. It isn’t pretty, but here’s how I do this first step:

# I'm going to make this into a proper script one day, but here it is as it currently stands
# Replace OBJECTNAME with the object name in the exposures
ls /raw/UVES.2010*.fits > raw.list.all.1
dfits `cat raw.list.all.1` | fitsort DPR.TYPE DPR.CATG EXPTIME OBJECT INS.MODE DPR.TECH | \
grep -v "SLIT" | grep -v "CDALIGN" | grep -v "SimCal" | grep -v "DARK" | grep -v "DFLAT" | grep -v "TEST" | grep -v "FIBRE" | \
awk 'NR > 1 {if ($3!="SCIENCE" || ($3=="SCIENCE" && $4>0.1)) print $0}' | \
awk '{if ($4>=300.0 || $3!="SCIENCE" || ($4<300.0 && $3=="SCIENCE" && ($5!="OBJECTNAME")) || (($3=="CALIB" || $3=="TEST") && ($6!="ECHELLE,ABSORPTION-CELL" || $7!="ECHELLE,ABSORPTION-CELL"))) print $0}' | \
awk '{print $1}' > raw.list.1
grep -f raw.list.1 -v raw.list.all.1 > raw.list.exclude.1

What should happen at this point is a file is made: raw.list.1 which has all of the science and their associated files that need to be reduced. An important point here — you have to use the full path names.

(I’ve never used the helpreduce.py script at this stage, so you can try it (let me know how it goes), or just use the following command).

$ UVES_headsort raw.list.1 -info raw.info -list -c 45 45 -d

If the object name is correctly filled out in the science exposures (a genuine “if”), you’ll have a file named vesta.list which looks like:

$ head vesta.list 

I’ve written a really simple python script that helps set up the reduction scripts — it’s not well-commented but it’s also not too complicated.

# 2011-11-16 helpreduce.py
import sys
import os
import subprocess
import argparse
parser = argparse.ArgumentParser(description="filename")
parser.add_argument('infile', action='store', type=str, help='grabs commandline filename')
args = parser.parse_args()
stem = args.infile
if args.infile.split('.')[-1] == 'list':
  stem = args.infile.split('.')[0]
basecommand = 'UVES_headsort ' +  stem + '.list -info ' + stem + '.info -c '
hours = 0
warning = 10
maxhours = 200
while warning > 5 and hours < maxhours:
  hours += 1
  linein = basecommand + str(hours) + ' ' + str(hours) + ' -d'
  proc = subprocess.Popen(shlex.split(linein), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  warning = len(proc.communicate()[0].split('\n'))
  print "Warnings: ", warning, "Hours: ", hours
if hours > maxhours:
print "Correct hours: ", hours
print "Final command: ", basecommand + str(hours) + ' ' + str(hours)
commandfile = open(stem + '.command','w')
print "Making command file."
print >>commandfile, basecommand + str(hours) + ' ' + str(hours)

The basic usage:

$ helpreduce.py vesta.list

It will run UVES_headsort in debug mode with an increasing range of hours around the exposures until it includes the files it needs — it will crap out if you don’t have the right (or enough) calibration files. When it runs properly, this script at the end produces two files: vesta.info and vesta.command. Run

$ source vesta.command

and you should have a directory vesta/ which, if you cd into it should reduction scripts named things like:

$ cd vesta; ls reduce*

If you’re feeling lucky, you can run:

$ source reduce_master.cpl

and it will go through all of the reduction scripts one at a time and do all of the magic.

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