3.6 Updates to calstis

The calstis modules evolve and improve with time, as we understand and characterize more fully the on-orbit performance of STIS. It is possible, even likely, that improvements in the calstis software will improve the calibration of your data. To determine the version of the software used to calibrate your data, note the value of the CAL_VER keyword in the primary header. The following example uses astropy.io.fits to print the rootname, the optical element, and the version of calstis for all _flt files in the current directory:

>>> from astropy.io.fits import fits
>>> hdr = fits.getheader('odbue5040_x1d.fits',0)
>>> print(hdr['ROOTNAME'], hdr['OPT_ELEM'], hdr['CAL_VER']

Watch the STScI Analysis Newsletters (STANs) or consult the STIS WWW pages for any announcement of enhancements to calstis. 

If you are uncertain whether a given enhancement to calstis merits recalibrating your data, contact the Help Desk. Often, it is instructive to re-calibrate (or simply re-request your data from the archive) and to determine empirically whether the revised calibration files or software affect the scientific interpretation of your data. If you need to upgrade your version of the stistools package, please refer to https://astroconda.readthedocs.io/en/latest/updating.html.