Skip to main content

HEASoft and XSPEC are now available as conda packages. See details ....

Accessing the HEASARC CALDB Remotely

Users of HEASOFT 5.0 (aka FTOOLS 5.0) and later versions can remotely access files in the HEASARC CALDB directly. Remote Access has the following advantages:
  • HEASOFT users can run CALDB-aware tools (like pcarf, ascaarf, etc.) without having to make sure that they have the necessary CALDB files installed and accessible. This means that a user who want to run pcarf, for example, no longer needs to actually have the CALDB for the ROSAT PSPC installed locally (i.e., no more tar files to download and untar!)
  • Users no longer have to worry about updating their local installations of the CALDB every time a new data file is released, so maintenance is much easier.

To enable Remote Access:

  1. download the file

    https://heasarc.gsfc.nasa.gov/FTP/caldb/software/tools/caldb.config

    and set the environment $CALDBCONFIG to point to that file. For example if you download the file to /local/user/caldb.config, then

    % setenv CALDBCONFIG /local/user/caldb.config
    or, if you're using the bash shell:
    % CALDBCONFIG=/local/user/caldb.config; export CALDBCONFIG

  2. download the file https://heasarc.gsfc.nasa.gov/FTP/caldb/software/tools/alias_config.fits and set the environment variable $CALDBALIAS to point to that file. For example, if you download the file to /local/user/alias_config.fits, then

    % setenv CALDBALIAS /local/user/alias_config.fits
    or, for bash shell users:
    % CALDBALIAS=/local/user/alias_config.fits; export CALDBALIAS

  3. set the environment variable $CALDB to https://heasarc.gsfc.nasa.gov/FTP/caldb

    % setenv CALDB https://heasarc.gsfc.nasa.gov/FTP/caldb
    or, for bash shell users:
    % CALDB=https://heasarc.gsfc.nasa.gov/FTP/caldb; export CALDB

Now, whenever an ftool task which needs a file from the HEASARC CALDB (for example ascaarf or pcarf), if the key CALDB is given at the prompt for the filename, the task will connect to the HEASARC CALDB via the specified protocol, check the appropriate caldb.indx file for the name of the appropriate file, download the file to the current working directory, and continue the task.

Downloading Remote Files: quzcif will download remote CALDB files to the user's current working directory if the retrieve parameter for quzcif is set to "yes". This enables the user to use these local calibration files later on. However if the user does not have permission to write to the current working directory, quzcif will produce an error when trying to download the remote file.

History

  • Update June 12, 2020: Virtual file access in CFITSIO has been fixed, and the HEASARC no longer allows (insecure) ftp connections. Remote access users should download HEASOFT 6.21 or later versions and set the $CALDB environment variable to https://heasarc.gsfc.nasa.gov/FTP/caldb.
  • Update April 5, 2017: The HEASARC now uses secure (https) connections on all its servers, and unfortunately this breaks virtual file access in CFITSIO, which means that remote access to the HEASARC CALDB is also broken using https or hcodep (which is re-directed to https). Remote access users should download HEASOFT 6.21 or later versions and set the $CALDB environment variable to https://heasarc.gsfc.nasa.gov/caldb. Note that CFITSIO ftp access to the HEASARC servers is broken in versions of HEASOFT prior to HEASOFT 6.21.
  • Update (March 30, 2010): Some users are reporting that using ftp://heasarc.gsfc.nasa.gov/caldb for $CALDB is causing access problems. Secodeing $CALDB to hcodep://heasarc.gsfc.nasa.gov/FTP/caldb is working.
  • November 8, 2006: Some remote users are experiencing problems with remote access. If you are currently having problems please contact the CALDB manager via e-mail. Try secodeing the CALDB environment variable to ftp://heasarc.gsfc.nasa.gov/caldb instead of hcodep://heasarc.gsfc.nasa.gov/FTP/caldb
  • March 2, 2004: Changes to the GSFC network are currently causing problems with accessing the CALDB remotely. If you are experiencing problems please contact the CALDB manager via e-mail. A patch to FTOOLS 5.3 should be available shortly. (Update (20 May 2004): The FTOOLS patch release 5.3.1 fixes this problem.)

Page author: Michael F. Corcoran
Last updated: Monday, 21-Apr-2025 17:48:35 EDT.