- ID:
- ivo://nasa.heasarc/fermigdays
- Title:
- Fermi GBM Daily Data
- Short Name:
- FERMIGDAYS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi GBM Daily Data database table contains entries for each day for which GBM data has been processed. The daily data products consist of GBM data that are produced continuously regardless of whether a burst occurred. Thus these products are the count rates from all detectors, the monitoring of the detector calibrations (e.g., the position of the 511 keV line), and the spacecraft position and orientation. Some days may also have event lists known as time-tagged event (TTE) files associated with them. These TTE files have the same format as those produced for bursts. Due to the large data volume associated with TTE files, only certain portions of the day considered of scientific interest to the instrument team will have TTE data. The underlying Level 0 data arrive continuously with each Ku band downlink. However, the GBM Instrument Operations Center (GIOC) will form FITS files of the resulting Level 1 data covering an entire calendar day (UTC); these daily files are then sent to the FSSC. Consequently, the data latency is about one day: the first bit from the beginning of a calendar day may arrive a few hours after the day began while the last bit will be processed and added to the data product file a few hours after the day ended. These data products may be sent to the FSSC file by file as they are produced, not necessarily in one package for a given day. Note that the data may include events from slightly before and slightly after the day official boundaries, which will be reflected in the start and stop times in the table. Consequently, some events may be listed in files for two consecutive days (e.g., at the end of one and the beginning of the next). Due to the continuous nature of GBM processing, new data files may arrive after the day has been included in Browse and reprocessed version may also arrive at any time. The reprocessed data will have the version number incremented (see file name conventions below). Browse will automatically download the latest versions of the data files. This database table was created by and is updated by the HEASARC based on information supplied by the Fermi Project. It is updated on a daily basis. The tte_flag parameter was added to the table in July 2010. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/fermilweek
- Title:
- Fermi LAT Weekly Data
- Short Name:
- FERMILWEEK
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi LAT Weekly Data database table provides access to LAT data binned into weekly files by the FSSC's data servers. For each week, the FSSC provides two FITS files: an all-sky file of photons containing positions, energies, etc. and a spacecraft pointing history file. The underscore separated fields in the file names indicate the file type (photon or spacecraft), the Fermi mission week (e.g., w009 = week 9), the processing version (which will change with each major reprocessing of LAT data), and a version number for the file itself. Note that currently the data may include events from slightly after the official week boundaries, which will be reflected in the start and stop times in the table. Any "run" of LAT data the FSSC receives that starts in a given week is put into the weekly file for that week and not broken up. Note additional selections must be applied to the weekly files prior to use in a data analysis. See <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/documentation/Cicerone/Cicerone_Data_Exploration/Data_preparation.html">LAT Data Selection Recommendations</a> and <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/LAT_caveats.html">Caveats About Analyzing LAT Data</a> for more information. For queries based on position, energy, and exact times, use the <a href="http://fermi.gsfc.nasa.gov/cgi-bin/ssc/LAT/LATDataQuery.cgi">FSSC's LAT data server</a>. This database table is created by the HEASARC from FITS tables received from the Fermi Science Support Center (FSSC). It is updated on a weekly basis. This is a service provided by NASA HEASARC .
