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Space Telescope Imaging Spectrograph
Differences in retrieval and calibration of pre-repair and

For these older data, the usual On-The-Fly-Recalibration (OTFR) system which re-calibrates the data using the latest reference files, has now been turned off, and the raw and calibrated files are instead retrieved from a static archive. This allows much faster retrieval times and reduces the load on STScI archive systems. New data taken after the repair will be processed through OTFR each time they are retrieved. This will allow the calibration to take into account the most up-to-date version of the calibration reference files and software. However, for now at least, data from 2004 or earlier will continue to be retrieved from the static archive. This means that the older data will not automatically take into account any future improvements in the STIS calibration reference files or software. If significant changes to the calibration are made, it is possible that the static archive will be updated to take these changes into account at some future time.