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PDS_VERSION_ID                    = PDS3
LABEL_REVISION_NOTE               = "M.R. SHOWALTER, 2003-12-04"
RECORD_TYPE                       = STREAM

OBJECT                            = DATA_SET
  DATA_SET_ID                     = "VG1/VG2-SR/UR-RSS-4-OCC-V1.0"

  OBJECT                          = DATA_SET_INFORMATION
  DATA_SET_NAME                   = "VG1/VG2 SR/UR RSS RESAMPLED
                                     RING OCCULTATION V1.0"

  ARCHIVE_STATUS                  = IN_PEER_REVIEW
  DATA_OBJECT_TYPE                = SERIES
  START_TIME                      = 1980-11-01T00:00:00
  STOP_TIME                       = 1986-02-01T00:00:00
  DATA_SET_RELEASE_DATE           = 2003-12-31

  DATA_SET_TERSE_DESC             = "
    This data set contains highly processed ring profiles of the rings
    of Saturn (Voyager 1) and Uranus (Voyager 2) produced by
    transmitting 3.6 and 13 cm wavelength coherent signals through the
    rings toward Earth."

  DATA_SET_DESC                   = "

  Data Set Overview
    This data set contains radio occultation data obtained during the
    Voyager 1 Saturn encounter and the Voyager 2 Uranus encounter.
    Only highly processed ring occultation data is included.

    Ring profiles are archived in a variety of formats, from the
    source files as provided to the Rings Node to calibrated and
    resampled optical depth profiles. Processing software, geometry
    solutions and calibration models are also provided.

    Data files contain ring normal opacity and phase shift of the
    X-band (3.6 cm) and S-band (13 cm) signals as they passed through
    the ring plane on their transit from Voyager to Earth.

    Some files contain the complex transmissivity of the ring, which
    is related to ring opacity and phase shift as follows:

    tau = normal opacity
    phi = phase shift

    T_norm = exp(-tau/(2*mu0)) = amplitude of the transmissivity

    T_re = T_norm * cos(phi) = real component of the transmissivity

    T_im = T_norm * sin(phi) = imaginary component of the

    Here mu0 is the cosine of the incidence angle.

    These data files are already highly processed, as summarized by
    [MAROUFETAL1986] for Saturn and [GRESHETAL1989] for Uranus.
    Further processing involves conventional resampling and smoothing.

    A variety of data files are included on this volume.

    Source data (S_RINGS/SORCDATA and U_RINGS/SORCDATA directories)
      The data files as contributed to the Rings Node by several
      investigators. These files are provided for documentation
      purposes and are not otherwise supported.

    Raw data (S_RINGS/RAWDATA and U_RINGS/RAWDATA directories)
      These files contain essentially the same data as are found in
      the SORCDATA directory, but in easier to use, PDS-compliant
      formats. Note that these are not raw in the conventional
      sense---they are in fact highly processed. However they serve as
      the raw materials from which the Rings Node generated its
      derived products.

    Edited data (S_RINGS/EDITDATA and U_RINGS/EDITDATA directories)
      Edited versions of the raw data, which in this case entails
      conversion from opacity and phase to complex transmissivity. The
      latter is more appropriate for smoothing and resampling.

    Derived profiles (S_RINGS/EASYDATA and S_RINGS/EASYDATA dirs)
      Easy-to-use ASCII data files containing ring opacity, phase and
      their uncertainty vs. radial location in a ring system. Files
      are included at a variety of radial resolutions. Because the
      rings of Uranus are narrow and inclined, there are separate
      profiles for each Uranian ring.

  Ancillary Data
    Several different types of ancillary data files are provided to
    describe the geometry and calibration during each occultation.

    Geometry models (S_RINGS/GEOMETRY and S_RINGS/GEOMETRY dirs)
      ASCII data files, containing a description of the ring intercept
      geometry, indexed to locations in the corresponding edited data
      files. Because the rings of Uranus are inclined, there are
      separate geometry files for each ring of these planets.

    Calibration models (S_RINGS/CALIB and S_RINGS/CALIB directories)
      ASCII data files, containing the modeled free space signal and
      noise power, indexed to locations in the corresponding edited
      data files.

    Ephemeris files (SPICE directory)
      Voyager ephemeris files for each of the planetary encounters, in
      SPICE format. For more information about SPICE data and
      toolkits, consult the PDS Navigation and Ancillary Information
      (NAIF) Node at:

  Coordinate System
    All geometric quantities appearing in the labels are in J2000
    coordinates. In this coordinate frame, the z-axis points
    northward along the Earth's J2000 rotation axis and the x-axis
    points toward the First Point of Aries. In some cases, B1950
    coordinate values are also included.

    Included on this disk is the source code for several libraries
    of software tools designed to be used with this and other ring
    occultation data sets.

    Light Label Library (SOFTWARE/OAL directory)
      A toolkit supported by the PDS Central Node for reading and
      writing PDS labels.

    Object Access Library (SOFTWARE/OAL directory)
      A toolkit supported by the PDS Central Node for reading and
      writing data objects described by PDS labels. Built atop the
      Light Label Library.

    Profile Library (SOFTWARE/PROFILE directory)
      A toolkit supported by the PDS Rings Node for manipulating
      one-dimensional profiles of planetary rings. Built atop the
      Light Label Library and the Object Access Library.

    Also included are the software tools to generate calibrated ring
    profiles at arbitrary resolution. These are the tools used to
    populate the EASYDATA subdirectories. These tools make full use of
    the above libraries.

    This data set is archived on compact disc (CDROM) media.
    Organization and formats are according to PDS and ISO 9660
    level 1 standards.

    Binary data files are provided in native formats for most
    platforms. Also, note that the software tools provided on this
    volume handle binary conversions on the fly if this is necessary."


  Confidence Level Overview

    Models for the noise power in the data can be found in the
    CALIB subdirectories. The ring profiles found in the EASYDATA
    subdirectories include estimates of the 50% confidence interval on
    opacity and phase.

  Peer Review
    Peer review of this data set is in progress.

  Data Coverage and Quality

    The RSS experiments provided complete coverage of the ring systems
    of Saturn and Uranus. At Uranus, both the ingress and egress
    occultations of each ring were observed.

    This data set does not include information about the regions
    between the known Uranian rings."

  END_OBJECT                    = DATA_SET_INFORMATION

  OBJECT                        = DATA_SET_TARGET
    TARGET_NAME                 = "S RINGS"
  END_OBJECT                    = DATA_SET_TARGET

  OBJECT                        = DATA_SET_TARGET
    TARGET_NAME                 = "U RINGS"
  END_OBJECT                    = DATA_SET_TARGET

  OBJECT                        = DATA_SET_HOST
    INSTRUMENT_HOST_ID          = VG1
    INSTRUMENT_ID               = RSSVG1SE
  END_OBJECT                    = DATA_SET_HOST

  OBJECT                        = DATA_SET_HOST
    INSTRUMENT_HOST_ID          = VG2
    INSTRUMENT_ID               = RSSVG2UD
  END_OBJECT                    = DATA_SET_HOST

    REFERENCE_KEY_ID            = "GRESHETAL1989"

    REFERENCE_KEY_ID            = "MAROUFETAL1986"

END_OBJECT                      = DATA_SET

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