Infrared Astronomical Satellite, IRAS

Product Name
Zodiacal Observation History Files


These data products are time-ordered versions of the entire IRAS sky survey and were created to aid modeling and extracting the zodiacal emission intensity in the various extended source data products. The databases retain the subdivision of the original survey into semi-daily Satellite Operation Programs (SOPs) and individual continuous survey scan observations (OBS). Two versions of the Zodial Observation History File (ZOHF) exist:

  • Standard ZOHF
  • A low-resolution version of the entire IRAS sky survey. The average of all detectors within a band produced a 0.5° wide fan beam which was then boxcar averaged for eight seconds to produce a 30' x 32' beam. Pointing information was similarly averaged over eight seconds to accompany the infrared data.

  • 2' Resolution ZOHF
  • An intermediate-resolution (2' in-scan x 30' cross-scan) version of the entire IRAS sky survey. The time averaging interval is one-half second rather than the eight seconds of the standard ZOHF.

    Infrared Astronomical Satellite (IRAS) Catalogs and Atlases, vol. 1, Explanatory Supplement, 1988, ed. C. Beichman, et al., NASA RP-1190 (Washington, DC: GPO)

    Version and release date: 30' 3.1, 1990 May; 2' 1.0, 1990 May.

    Zodiacal Observation History Files

    Explanation of color correction

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    A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
    Goddard Space Flight Center, National Aeronautics and Space Administration
    HEASARC Director: Dr. Alan P. Smale
    LAMBDA Director: Dr. Eric R. Switzer
    NASA Official: Dr. Eric R. Switzer
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