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RXTE SOF Realtime Data

Welcome to the updated RXTE SOF Realtime Data area!

We offer two types of "early data processing" products here:

  • Realtime Data ("FITS" area)
    These data are created within a few hours after the observation takes place. They are made from the realtime data stream, and processed with the predicted version of the observing schedule (as opposed to the "as-flown" observing schedule). These data remain available until pseudo-production data arrive for the given observation (see next item).

    Realtime data differ from fully-processed data in these main respects:

    • The obsid name is not in the FITS files (instead, the day of observation is used).
    • The RA and Dec pointing position is "0.0" for these data. (Users must put the RA and Dec into the datafiles, if they are using software that expects it.) See our Working with Realtime Data recipe, for further details.
    • The accuracy of the start and stop times of observations is only good to +/- 1 minute, due to use of the predictive schedule. Timing accuracy of RXTE science data is normal.
    • Last minute changes in the schedule (such as direct slews to a new source), will cause data to be mislabeled: e.g., if observation 90801-06-10-01 (a background observation) was scheduled, but a new transient was observed at the last minute in place of this observation, then the dataset named 90801-06-10-01.tar.pgp will contain the data from the new transient.
    • Always use these data with caution, as a "first look" at the observation. Verify your results later, against the fully-processed data and/or the as-flown timeline. The fully processed data and as-flown timeline are usually available 8 days after observation. See below for links to fully-processed data. Search the as-flown timeline.

  • Pseudo-production Data ("FITS/production" area)
    These data are made from the full-production data, which arrive about one day after observation. They do not suffer the data drop outs that can occur in realtime data. They are made with a predicted version of the observing schedule, similar to realtime data. However, they undergo extra processing, so that the file formats of pseudo-production data more closely resemble full-production data, and can be used in most HEASoft tools designed for RXTE data analysis. These data are present for approximately 30 days after observation, and remain until disk space is need for newer data. Users looking for data after that should use the fully-processed production data, which become available usually 8 days after observation. For more information on fully-processed production data, see this help file for fully-processed proprietary data retrieval or get fully-processed public data from the RXTE Archive

    Pseudo-production data have these properties:

    • The obsid name, RA, and Dec are included in the file headers (unlike realtime data)
    • The data have a directory structure identical to full-production data (eg.,: AO10/P91801/91801-01-01-00 will be the top directories in the tar file for observation 91801-01-01-00)
    • The accuracy of the start and stop times of observations is only good to +/- 1 minute, due to use of the predictive schedule. Timing accuracy of RXTE science data is normal.
    • Last minute changes in the schedule (such as direct slews to a new source), may still cause data to be mislabeled: e.g., if observation 90801-06-10-01 (a background observation) was scheduled, but a new transient was observed at the last minute in place of this observation, then the dataset named 90801-06-10-01.tar.pgp may contain the data from the new transient.
    • Use these data with caution, as a good early look at the data but not the final, best processing. In particular, if the characteristics of a known source seem highly unusual, verify the data come from the correct source. One way to do this is to Create a Filter File for the observation, and then plot the "offset" column from the filter file. "Offset" measure the difference between the source location in the file header and the spacecraft's actual pointing.



For questions about scheduling of RXTE observations please send email to xteplan@athena.gsfc.nasa.gov If you have other questions about RXTE, please send email to one of our help desks.

This page is maintained by the RXTE SOF and was last modified on Thursday, 14-Aug-2008 15:18:53 EDT.

Responsible NASA Official: Phil Newman
Web Curator: Robin Corbet

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