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All WFPC, FOC, FOS, GHRS, HSP observations taken by the Hubble Space Telescope are automatically processed by the Routine Science Data Processing (RSDP) ``pipeline'' at STScI, under the Post Observation Data Processing System (PODPS) branch. Over 36,000 readouts have been processed since launch, 97\% of these within two days of execution.
Packetized science data enter the pipeline after telemetry bit-error correction at the Data Capture Facility, GSFC. Software sorts the data by observation, inserts fill packets as needed, and examines the data structure for errors. If none, the Edited Information Set is converted into a generic (waivered FITS) format. If repair is required (1-2\% of observations), tested procedures are used to modify erroneous bits or keywords. The observation is then calibrated, and a film file or laser plot is generated. The HST instrument teams supply all information for calibration performed by RSDP. As calibration evolves, PODPS updates the flat fields and other files and tables for subsequent pipeline processing. Also, the observer may recalibrate the data with STSDAS tools.
PODPS staff astronomers, using STSDAS IRAF tasks and SAOimage, evaluate the quality of each observation and provide keywords such as `OK' or `UNDEREXP' plus informative comments to the archive catalog. Comments often include information from the Observation Support Branch (OSS) regarding guide star acquisition success, centering slews, high jitter, etc. Observation data (in packetized, reformatted, and calibrated form) and their comments are placed in the HST science and ancillary optical disk archives (now by DMF, to be superseded by DADS). FITS tapes containing both uncalibrated and calibrated files are written for the GO by the Data Systems Operations Branch (DSOB), and prints or plots plus OSS and PODPS comments are mailed with the tapes.
The authors are staff members of the Space Telescope Science Institute.
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