About STSDAS

The Institute

HST

JWST

Community Missions

Data Archives

News and Outreach

Resources

Introduction to STSDAS

The Space Telescope Science Data Analysis System (STSDAS) is software for calibrating and analyzing data from the Hubble Space Telescope (HST). STSDAS includes the same calibration routines as are used in the STScI operational data processing pipeline, as well as general-purpose tools and enhancements to the Image Reduction and Analysis Facility (IRAF).

IRAF provides the user interface (command language, or CL) and general purpose graphic and image display facilities. Because STSDAS is layered on IRAF, the system runs on any computing platform for which an IRAF port is available, including most Unix systems. STSDAS can also be used with PyRAF.

STSDAS Package Organization

Programs in STSDAS are called tasks. Tasks are grouped by function into packages, which can themselves be further grouped into packages.

analysis             Data analysis packages. 
   dither            Dithered image combination.
   fitting           Curve fitting tools. 
   fourier           Fourier analysis. 
   gasp              Access the HST Guide Star Catalog on CD-ROM. 
   isophote          Elliptical isophote image analysis. 
   nebular           Tasks for analyzing nebular emission lines 
   restore           Deconvolve or filter 1- or 2-dimensional images. 
   statistics        Statistical analysis software. 
contrib              User-contributed software. 
   redshift          Tasks for determining redshifts and dispersions. 
   spfitpkg          Tasks for fitting spectra with non-linear chi-square
                            minimization 
   vla               Spectral image reduction for VLA data. 
fitsio               FITS input/output for Space Telescope data
                            (images and tables).
graphics             Graphics and image display packages.
   sdisplay          Image display package for SAOImage display device. 
   stplot            General plotting utilities. 
hst_calib            HST Science Instrument calibration packages. 
   acs               Tasks for calibrating ACS data. 
   ctools            General calibration tools. 
   foc               Tasks for calibrating FOC data. 
         focprism    FOC prism package. 
   fos               Tasks for calibrating FOS data. 
         spec_polar  Tasks for reducing and analyzing FOS polarimetry 
                            observations. 
   hrs               Tasks for calibrating HRS data. 
   nicmos            Tasks for calibrating NICMOS data. 
         mstools     General-purpose tasks that handle NICMOS IMSETs. 
   paperprod         Tasks for generating paper products. 
   stis              Tasks for calibrating STIS data. 
   synphot           Tasks for synthetic photometry and modelling
                            instrument response. 
   wfpc              Tasks for calibrating WFPC and WFPC-2 data. 
         w_calib     Tasks for deriving the WF/PC instrument calibration. 
playpen              Miscellaneous experimental tasks.
sobsolete            Package of tasks that have been retired. 
   foccs             FOC calibration software package. 
   focgeom           FOC geometry package. 
   focphot           FOC photometry package. 
   focutility        Obsolete FOC utility package 
   hsp               Tasks for calibrating HSP data. 
   registration      Compute registration parameters and resample
                            unaligned data files 
   testdata          Tools for creating artificial images. 
   timeseries        Time series photometry data reduction and analysis. 
   y_calib           Tasks supporting the FOS calibration process. 
   z_calib           Tasks supporting the HRS calibration process. 
toolbox              General tools packages.
   convfile          Reformat images from one machine type to another 
                            (VAX <-> Sun only). 
   headers           Tools for modifying image headers. 
   imgtools          Tools for manipulating & examining images
                            and bad pixel lists. 
         mstools     Tasks to handle STIS/NICMOS IMSETs.
   tools             Generic data handling and utility tools. 
   ttools            Table manipulation tools.

You can see an alphabetical list of task names as part of our online help system.

More complete documentation can be found in the HST Data Handbook, which includes an overview of how to use STSDAS to accomplish basic tasks and how to use tasks that are specific to the HST instruments. The STSDAS User Guide was last updated in 1994(!), but does contain information on some of the older packages in STSDAS.