Voyager pic
    Instrument Characteristics
    The Voyager IRIS instrument consists of a Michelson interferometer for measurements in the thermal infrared and a single channel radiometer that operates in the visible and near infrared. The two components of the instrument share a 50 cm Cassegrain telescope with an effective focal length of 303.5 cm. The angular field of view is 0.25 degree.

    IRIS Science Objectives

    • Determination of atmospheric vertical thermal structure (which in turn aids modeling of atmospheric dynamics).
    • Measurement of the abundances of hydrogen and helium (as a check on theories regarding their ratio in the primitive solar nebula).
    • Determination of the balance of energy radiated to that absorbed from the sun (to help investigate planetary origin, evolution, and internal processes).

    • References Helpful in Scoping the Mission
      Mission Description
      Spacecraft Description

      The IRIS Data
      Instrument Description
      Voyager 1
      Voyager 2
      Also see Space Science Reviews 21 (1977 – Issue 2) 129-157.

      The Reduced Data Records (RDR) for Jupiter contains measurements from both the infrared interferometer spectrometer and the broadband reflected solar radiometer and ancillary data. The data is ordered by time as measured by the Flight Data System Count (FDSC). And includes pointing and other information on the geometry associated with a given data record.

      Other Documentation

      A separate explanatory file is included for each planet: Jupiter, Saturn, Uranus, and Neptune. Included are information on the reduction and calibration of the data sets, brief discussions of the data quality, and a list of relevant references.


      Calibrated Data - Voyager 1 and 2 Derived Data - Voyager 1 and 2
      North-South Scans
      Red Spot Parameters


      Calibrated Data - Voyager 1 and 2 Derived Data - Voyager 1 and 2
      North-South Scans

      Titan data is included in the Saturn data file
      Calibrated Data - Voyager 1 and 2
      Voyager 1, the close encounter, spans 1980-08-27 to 1980-11-15
      Voyager 2 spans 1981-06-24 to 1981-08-25


      Calibrated Data - Voyager 2


      Calibrated Data - Voyager 2

      Publications - A listing of team members to facilitate literature searches.

      Observation geometry in "SPICE" format may be obtained at the NAIF node