PODPS: HST Pipeline to the Universe

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Session 3 -- HST Performance and Process
Display presentation, Monday, 30, 1994, 9:20-6:30

[3.06] PODPS: HST Pipeline to the Universe

A.B.~Schultz, S.B.~Parsons, D.A.~Swade, R.C.~Dempsey, E.A.~Giovane, M.C.~Kochte, E.~Rosenthal, J.F.~Scott, S.E.~Slowinski (Astronomy Programs, CSC/STScI)

The Post Observation Data Processing System (PODPS) Branch, Space Telescope Science Institute, Baltimore, MD is responsible for processing and quality evaluation of all science observations of the Hubble Space Telescope (HST). PODPS staff maintain the Routine Science Data Processing (RSDP) pipeline and are responsible for submitting to the HST archive the science observations, engineering, astrometry, orbit definition files, and other data files generated by OSS (Observation Support System) and SPSS (Science Planning and Scheduling System). Since the launch of HST in April 1990, over 50,000 readouts have been processed, 97\% of these within two days of execution.

Each HST science observation (WFPC2, FOC, FOS, GHRS) is received at the Data Capture Facility (DCF), GSFC. DCF performs telemetry bit-error correction and transmits the data to PODPS. RSDP pipeline software sorts the data by observation, inserts fill packets as needed, and examines the data structure for errors. These data are converted into a Generic Edited Information Set (GEIS) and calibrated. The GEIS FITS-like header is stored separate from the data array. About 1-2\% of observations require some repair usually with standard procedures to correct erroneous bits or keywords. Science observations are represented in a variety of output products: film, gray scale laser printer image, or laser printer plots. The observers can use STSDAS and updated reference files to recalibrate their data.

A PODPS OA (Operations Astronomer) performs the quality evaluation of each observation and files a PODPS Data Quality Report (PDQ file). The PDQ file contains a keyword to indicate the overall quality (OK, UNDEREXP, UNKNOWN, ...), a general quality comment for the HST archive, and comments from OSS. DSOB (Data Systems Operations Branch) staff write observations to FITS tape(s) and mail the tape(s) plus OSS and PODPS comments to the PI.

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