Fermi Gamma-ray Space Telescope

Caveats About the Fermi Data Server

Here we provide a listing of known issues, errors, or other conditions with the FSSC LAT data server that may affect the science data or the delivery of data.

Current Issues:

  • Due to a hardware failure in November 2009, the weekly file LAT_allsky_279807739.000_V01.fits was corrupted. Approximately 36000 duplicate entries were found and removed from the weekly file. These duplicates have affected all event classes. So if you are using this file for data analysis you are advised to download the new version. The file was corrected on March 6, 2010 at ~10:50 am EST so users who downloaded the file after that should not have a problem.
  • LAT event records are not stored or delivered in time order. For users wishing to perform pulsar analyses which benefit from time-ordering of events, it is suggested that you sort the data using the ftsort FTOOL.
  • If END is used for the time entry, the LAT events and spacecraft files use the same time for that end of the data file. To use such files with the pulsar tools, the events file should be shortened by 30 seconds with respect to the spacecraft file.

Please contact the FSSC helpdesk with any questions.

Last updated by: Elizabeth Ferrara - 04/12/2010