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Last modified: March 2017

URL: http://cxc.harvard.edu/ciao/ahelp/download_obsid_caldb.html
AHELP for CIAO 4.9

download_obsid_caldb

Context: tools

Synopsis

Download the CALDB files required to analyze an OBS_ID

Syntax

download_obsid_caldb  infile outdir [background] [missing] [clobber]
[verbose]

Description

`download_obsid_caldb' will perform a partial download of the Chandra Calibration Database (CALDB) required to analyze a specific dataset. The file size of the Chandra CALDB has become prohibitive for certain users on slow internet connections and those with limited free disk space. This tool allows them to only download the files required for their specific analysis.

The tool retrieves the most recent version of the CALDB index files from the Chandra archive FTP server, and then uses the input event file to construct CALDB queries for all the calibration files associated with that dataset. Those files are then retrieved and stored in the user's local CALDB directory.

The default is to store the CALDB files in the root of the CIAO installation: $ASCDS_INSTALL/CALDB. Then as each dataset is analyzed, users can accumulate the CALDB files in a single location. Alternatively, users may wish to use a local CALDB directory where they can maintain all their data files in a single location; this approach requires additional setup by the user as shown in the Examples.

The default clobber=no means that existing files in the CALDB are not overwritten; they are skipped. Chandra observations closely spaced in time often share the same CALDB files. This allows for only the unique files to be retrieved further saving bandwidth and disk space.

Example 1

unix% download_chandra_obsid 635
unix% download_obsid_caldb 635/primary/acisf00635N0000_evt2.fits.gz

The basic example is to simply provide the tool the name of an events file. The tool will prompt for the location of output CALDB directory

Output CALDB directory (${ASCDS_INSTALL}/CALDB -> /soft/ciao/CALDB):
download_obsid_caldb
          infile = 635/primary/acisf00635N0000_evt2.fits.gz
          outdir = /soft/ciao/CALDB
      background = no
         missing = no
         clobber = no
         verbose = 1
            mode = ql

Retrieving files for CALDB_VER = 4.6.8
Retrieving CALDB index files
Processing infile=635/primary/acisf00635N0000_evt2.fits.gz
Retrieving CALDB data files
    Filename:                               0------------------1
    telD1999-07-23aimptsN0002.fits          ####################
    telD1999-07-23skyN0002.fits             ####################
    telD1999-07-23geomN0006.fits            ####################
    telD1999-07-23sgeomN0001.fits           ####################
    telD1999-07-23tdetN0001.fits            ####################
    hrmaD1996-12-20vignetN0003.fits         ####################
    acisD1997-04-17qeN0006.fits             ####################
    acisD1999-08-13contamN0009.fits         ####################
    acisD2000-01-29qeuN0007.fits            ####################
    acisD2000-01-29badpixN0003.fits         ####################
    hrmaD1996-12-20axeffaN0008.fits         ####################
    acisD1996-11-01gradeN0004.fits          ####################
    acisD2000-01-29t_gainN0006.fits         ####################
    acisD2000-01-29grdimgN0001.fits         ####################
    acisD1999-07-22subpixN0001.fits         ####################
    acisD1996-11-01evtspltN0002.fits        ####################
    acisD2000-01-29gain_ctiN0006.fits       ####################
    acisD2000-01-29ctiN0007.fits            ####################
    acisD2000-01-29fef_pha_ctiN0004.fits    ####################
    acisD1999-09-16dead_areaN0001.fits      ####################
    hrmaD1996-12-20reefN0001.fits           ####################
    acisD2000-01-29p2_respN0006.fits        ####################
    hrmaD1996-11-01wpsfN0001.fits           ####################
    acisD2000-01-29osip_ctiN0006.fits       ####################

If the output directory is different from the ${CALDB} environment variable (or if the CALDB environment variable is not set), the user will see the following message:

Be sure to setup the following environment variables to
use these CALDB files.

(t)csh:
setenv CALDB /soft/ciao/CALDB
setenv CALDBCONFIG /soft/ciao/CALDB/software/tools/caldb.config 

bash:
export CALDB=/tmp
export CALDBCONFIG=/soft/ciao/CALDB/software/tools/caldb.config 

If the user has used the default output directory, then the next time they source the CIAO setup scripts these CALDB environment variables will automatically be set.

Example 2

unix% download_obsid_caldb 635/

Similar to above, except the directory is input. The tool will search for files named "*evt*" in the input directory along with the "repro", "primary", and "secondary" directories (if they exist).

Example 3

unix% download_obsid_caldb 635/ 635/CALDB

Similar to above except now that CALDB files are retrieved and stored locally with the observation's data products. This makes is easy to share or archive the analysis as a single tar file. It also allows the user to isolate their analysis of this one observation from system wide/global CALDB updates; changes to CALDB version in the middle of analysis may yield unpredictable results.

download_obsid_caldb
          infile = 635/
          outdir = 635/CALDB
      background = no
         missing = no
         clobber = no
         verbose = 1
            mode = ql

Retrieving files for CALDB_VER = 4.6.8
Retrieving CALDB index files
Multiple event file found, using 635//repro/acisf00635_repro_evt2.fits
Processing infile=635//repro/acisf00635_repro_evt2.fits
Retrieving CALDB data files
    Filename:                               0------------------1
    telD1999-07-23aimptsN0002.fits          ####################
    telD1999-07-23skyN0002.fits             ####################
    ...
    hrmaD1996-11-01wpsfN0001.fits           ####################
    acisD2000-01-29osip_ctiN0006.fits       ####################

Be sure to setup the following environment variables to
use these CALDB files.

(t)csh:
setenv CALDB /tmp/635/CALDB
setenv CALDBCONFIG /tmp/635/CALDB/software/tools/caldb.config

bash:
export CALDB=/tmp/635/CALDB
export CALDBCONFIG=/tmp/635/CALDB/software/tools/caldb.config

Users must setup these environment variable each them they start CIAO and/or when they change observation. Note: The CALDB requires full, absolute path names be specified so the relative path is expanded when setting the environment variables. Failure to change these environment variables may cause various CIAO tasks to fail badly.

Example 4

unix% download_obsid_caldb 635/ 635/CALDB background=yes

By default the ACIS and HRC background files are not retrieved. They can be requested by setting background=yes.

download_obsid_caldb
          infile = 635/
          outdir = 635/CALDB
      background = yes
         missing = no
         clobber = no
         verbose = 1
            mode = ql

Retrieving files for CALDB_VER = 4.6.8
Retrieving CALDB index files
Multiple event file found, using 635//repro/acisf00635_repro_evt2.fits
Processing infile=635//repro/acisf00635_repro_evt2.fits
Retrieving CALDB data files
    Filename:                               0------------------1
    telD1999-07-23aimptsN0002.fits          .................... (skipped)
    telD1999-07-23skyN0002.fits             .................... (skipped)
    ...
    acisD2000-01-29osip_ctiN0006.fits       .................... (skipped)
    acis2iD2000-01-29bkgrnd_ctiN0005.fits   ####################
    acis3iD2000-01-29bkgrnd_ctiN0005.fits   ####################
    acis0iD2000-01-29bkgrnd_ctiN0005.fits   ####################
    acis1iD2000-01-29bkgrnd_ctiN0005.fits   ####################
    acis6iD2000-01-29bkgrnd_ctiN0005.fits   ####################

Since the other CALDB files have already been retrieved, and clobber=no, they are skipped and only the background files are actually retrieved.

Parameters

name type ftype def min max reqd
infile file input       yes
outdir file output ${ASCDS_INSTALL}/CALDB     yes
background boolean   no     no
missing boolean   no     no
clobber boolean   no      
verbose integer   1 0 5  

Detailed Parameter Descriptions

Parameter=infile (file required filetype=input)

Input event file or directory name

The file name of an event file or the directory name that contains an event file (tool looks for "*evt*"). The header of the event file is used to setup the CALDB query for the specific observation. The event file must have standard Chandra header and include keywords such as INSTRUME, TELESCOP, DETNAM, DATE-OBS, DATE-END, GRATING just to list a few. The exact keyword list depends on the calibration products.

If a directory name is specified, the tool looks for files named "*evt*" in that directory, and then looks in subdirectories: "repro", "primary", and "secondary". If more than one event file is found, the first one is used.

Parameter=outdir (file required filetype=output default=${ASCDS_INSTALL}/CALDB)

The output CALDB directory name

The directory containing the CALDB files. This should be the top level of the CALDB directory that usually has 3 or 4 sub-directories: 'data', 'docs', 'software', and possibly 'config'. The standard, centralized CIAO installation location is $ASCDS_INSTALL/CALDB. With the CALDB installed in this location the CIAO setup scripts will automatically setup the correct CALDB environment variables to use it.

If the outdir directory is different than the $CALDB environment variable or if the CALDB environment variable is not set, the tool will provide instructions for setting the environment variables needed to access the CALDB files.

Parameter=background (boolean not required default=no)

Retrieve the ACIS|HRC background files?

Due to their size, the ACIS and HRC background files are not retrieved by default. Setting this parameter to 'yes' will retrieve the files appropriate for the current observation.

Note: there may be some certain background file types that this script cannot locate. If that is the case, users will need to retrieve the entire set of background files.

Parameter=missing (boolean not required default=no)

Only check for missing files?

When missing=yes, the tool will check the current version of the CALDB configuration and index files against the files in the outdir/ CALDB tree and provides feedback for any files that are missing. This can be used to check whether the current partial CALDB has all the files needed for analysis.

Note that this only checks the current version of the index files. If there is a newer version of the CALDB, then those index files will be retrieved, which may mean that there may be additional files that are required.

Parameter=clobber (boolean default=no)

Overwrite existing files?

With missing=no (default), this script will always overwrite the CALDB index and config files with the latest version. The clobber parameter controls whether the individual CALDB files are downloaded again.

Parameter=verbose (integer default=1 min=0 max=5)

Amount of tool chatter

Changes in the scripts 4.9.3 (May 2017) release

Updated to use ftp://cda.cfa.harvard.edu as the default FTP server.

Changes in the scripts 4.9.2 (April 2017) release

Fix problem when the outdir ends with a trailing "/" character.

About Contributed Software

This script is not an official part of the CIAO release but is made available as "contributed" software via the CIAO scripts page. Please see the installation instructions page for help on installing the package.

Bugs

There are no known bugs for this tool.

See Also

calibration
ardlib, caldb
contrib
cda_data, cda_search
tools
calindex, calmerge, calquiz, calvalid, check_ciao_caldb, download_chandra_obsid, find_chandra_obsid, list_datasetid, obsid_search_csc, search_csc, splitobs

Last modified: March 2017
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