Science data obtained with HST are sent to the TDRSS satellite system, from there to the TDRSS ground station at White Sands, New Mexico, then to the Sensor Data Processing Facility at Goddard Space Flight Center in Greenbelt, Maryland, and then finally to STScI.
Standard calibrations performed on HST data, and the resulting output data products, are described in detail in the
HST Data Handbook. The Archive no longer saves the initial versions of the calibrated data (since 2000), nor the initial version of the uncalibrated FITS data (since 2005). Instead, when a data request is submitted for all ACS, COS and WFC3, as well as all NICMOS and STIS data acquired after Servicing Mission 4, the Archive production pipeline processes the data “on-the-fly” using the best available reference files, starting with the spacecraft packet format files, as described in
Section 7.2.1. Data from first generation instruments (FOC, FOS, HSP, WFPC1), WFPC2, and NICMOS, are maintained in a Static Archive.
The Space Telescope Science Data Analysis System (STSDAS), and its accompanying package called TABLES, provides access to all the existing calibration pipeline programs used by STScI to process all HST data so that
HST observers can recalibrate their data, examine intermediate calibration steps, and re-run the pipeline using different calibration switch settings and reference data as appropriate.
STSDAS also has various applications for the analysis of HST data as well as various utilities for manipulating and plotting data. The TABLES package facilitates the manipulation of FITS table data. STSDAS and TABLES were originally layered onto the Image Reduction and Analysis Facility (IRAF) software from the National Optical Astronomy Observatories (NOAO). Both packages run from within IRAF and are supported on a variety of platforms, although not all of the platforms that IRAF supports.
