Data Set Overview
      =================
      This data presented with this data set include
 
      FPA.TAB - The IRAS Detector File which provides for each
                detector of the focal plane array its operational
                status, associated filter, location, dimension,
                sterradiance, and readout time offset.
 
      BAND1_12MU.TAB - The transmission and response values given in
                this table are to energy/wavelength and represent
                averages over all of the IRAS detectors of Band 1 (12
                microns).
 
      BAND2_25MU.TAB - The transmission and response values given in
                this table are to energy/wavelength and represent
                averages over all of the IRAS detectors of Band 2 (25
                microns).
 
      BAND3_60MU.TAB - The transmission and response values given in
                this table are to energy/wavelength and represent
                averages over all of the IRAS detectors of Band 3 (60
                microns).
 
      BAND4_100MU.TAB - The transmission and response values given in
                this table are to energy/wavelength and represent
                averages over all of the IRAS detectors of Band 4 (100
                microns).
 
 
      Modification History
      ====================
      In Feb. 2002 this data set was reviewed internally as part of a
      general inventory review and upgrade. At that time in addition
      to minor format editing the following changes were made to the
      label files:
 
       - The names of the filter files were changed to reflect the
         band number and center wavelength. These changes were
         propagated to this file as well.
 
       - The PRODUCT_NAME field was modified to include the name
         of the spacecraft.
 
      The associated catalog files, including this one, were upgraded
      to current standards at the same time.

Review
        ======
        FPA.TAB underwent peer review on March 24, 1997.
 
        FILTER1.TAB, FILTER2.TAB, FILTER3.TAB, and FILTER4.TAB were peer
        reviewed on April 26, 1993, and updated on March 24, 1997.
 
        Focal Plane Model
        -----------------
        An explication of the focal plane model adopted here is given in
        McCallon (1992) [MCCALLON1992].
 
        Detector Spectral Response
        --------------------------
        The detector spectral response of the Ge:Ga detectors used at
        100 microns was assumed to be the same as that of the 60 micron
        detectors even though the material came from a different source.
        Limits on out-of-band leaks, at short and long wavelengths, are
        tabulated in Beichman et. al (1988) [BEICHMANETAL1988]. At 12
        and 25 microns, these leaks effect the calibration by less than
        0.02 percent. At 60 and 100 microns, the effect is less than 10
        percent.