CALSTIS is the name of the software task that performs routine calibration of STIS data in the STScI "data pipeline." The version of CALSTIS used to calibrate a set of data can be found in the CAL_VER primary header keyword of the calibrated data files. The major changes made in each version of calstis are provided in the Pipeline Software History.

CALSTIS also exists as a task in the STSDAS package (hst_calib.stis) and can be run by the observer to customize the calibration process. The major elements of CALSTIS are:

CALSTIS	all processing steps
BASIC2D	bias and dark subtraction, flat-fielding
OCRREJECT	cosmic-ray rejection
WAVECAL	WAVECAL processing
X2D	2-D spectral rectification
X1D	1-D spectral extraction