Introduction to Reducing HST Data

A.3 Getting IRAF and STSDAS

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Both IRAF and STSDAS are provided free of charge to the astronomical community. You must have IRAF and PyRAF to run STSDAS. Detailed information about installing and retrieving STSDAS is found in the STSDAS Site Manager's Installation Guide and Reference which can be downloaded in postscript or PDF format from the World Wide Web page at:

http://www.stsci.edu/resources/software_hardware/stsdas/download

If you have any problems getting and installing STSDAS, TABLES, or any other packages or data described in this handbook, please contact the Help Desk by sending e-mail to: help@stsci.edu.

A complete description of how to install the synphot data files is provided in Section A.3.2.

A.3.1 Retrieving the IRAF and STSDAS Software

There are two ways to get the software:

1. Use the World Wide Web page shown above

This page provides links and instructions for downloading the appropriate files to your local system or to display the software directory, from which you can select a series of smaller files.

2. Use anonymous FTP

Type ftp ftp.stsci.edu

login: anonymous

password: (your e-mail address)

and go to the directory software/stsdas to retrieve source and binary files. Binaries are platform-specific and the filename contains the name of the platform; see the README file in that directory.

When you retrieve STSDAS, you should also retrieve the TABLES package. TABLES must be installed prior to STSDAS. You must have IRAF and Pyraf installed on your system in order to install TABLES and STSDAS.

The complete instructions for installing STSDAS, TABLES, and all of the supporting software and reference files (including instrument reference files and the synphot dataset) for the IRAF environment are found in the file called InstallGuide.book32.ps (which contains a copy of the STSDAS Site Manager's Installation Guide and Reference). Ancillary information and documentation for STSDAS and synphot are available in the software/stsdas/docs directory on the ftp site.

Registration

The software can also be registered and requested using on-line forms available through World Wide Web at the following URL:

http://www.stsci.edu./resources/software_hardware/stsdas/STSDASRegistrationForm

When you request the STSDAS software, you can also ask for the appropriate version of IRAF, which will be requested for you; simply check the appropriate box on the form under "Do You Already Have IRAF Installed?" If you prefer to request the IRAF software independent of STSDAS, you can do so by sending e-mail to: iraf@noao.edu

A.3.2 Getting the Synphot Database

This handbook sometimes refers to the synphot dataset, which must be available in order to run tasks in the STSDAS synphot package. These data files are not included with the STSDAS software and must be retrieved independently. To do this, you may either retrieve the Synphot data on-line at www.stsci.edu/resources/software_hardware/stsdas/synphot or you can retrieve a series of compressed tar files from the STScI FTP site in the directory software/stsdas/refdata/synphot.

After uncompressing and extracting the tar files, you need to unpack the FITS files as described below.

The synthetic photometry data are read in a similar way as the instrument datasets, using the script unpack.cl provided in the top directory. This script is run within IRAF to convert data from FITS format into the format used by the synphot task. This script assumes you have the logical crrefer set up in your extern.pkg file (which is in the directory $iraf/unix/hlib) or have it set up in your session. You can do this by placing the command below in extern.pkg or by typing it on the command line:

set crrefer = "/node/partition/stdata/synphot/"

 

Figure A.7 shows how to convert the files.

Figure A.7: Unpacking Synthetic Photometry Files


 

Alternatively you may retrieve the synphot data on-line at:

http://www.stsci.edu/resources/software_hardware/stsdas/synphot

and follow the instructions for downloading and installing it.

Note that all five synphot files must be unloaded for the script to complete successfully.

A.3.3 Extracting the Synphot Unix Tar Files

If you retrieved the synphot database as compressed tar files, you will need to copy them to an appropriate subdirectory and then expand and unpack the files. The tar and compress utilities that do this are commonly available on most Unix systems, but are not standard in the VMS environment. The examples shown below reflect Unix usage. If you are on a VMS system, you should consult with your systems support staff regarding the availability and usage of these commands. To process the files on a Unix system:

1. Get the compressed tar file that you want, as described in previous sections.
2. Make an appropriate subdirectory using the mkdir command.
3. Pipe the compressed tar file through the uncompress and tar utilities to expand and unpack the file.

The following example shows how to do this. The example assumes that you are putting the files in a subdirectory under /usr/iraf/stdata (Note that the name of your file is assumed to be XXX.tar.Z).

% pwd /usr/iraf/stdata % mkdir MYPROJECT % mv XXX.tar.Z MYPROJECT/ % cd MYPROJECT % cat XXX.tar.Z | uncompress | tar -xf -

 

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