Data Set Overview
    =================
      This is a regeneration of the Voyager 1 and 2 images from Jupiter,
      in multiple versions including decompressed raw, cleaned,
      calibrated and geometrically corrected forms. It has been
      derived from the earlier PDS data set VG1/VG2-J-ISS-2-EDR-V1.0,
      which appeared on volumes VG_0006, VG_0007, VG_0008 and VG_0013 to
      VG_0025.

      The information covers Voyager 1 and 2 at Jupiter (1979),
      including the planet, its satellites and rings. Pointing
      information is not included in this data set.

      The data set is organized chronologically for each Voyager
      encounter. Volumes VGISS_5101-5120 contain the Voyager 1 images;
      volumes VGISS_5201-5214 contain the Voyager 2 images. For each
      Voyager image, the following files are included:

      RAW     - The decompressed raw image.
      RESLOC  - A table of reseau locations.
      GEOMA   - A table of tiepoints describing the geometric
                correction of the image.
      CLEANED - The raw image with various spikes, blemishes and
                reseau markings removed.
      CALIB   - The calibrated image, in which data numbers are
                directly proportional to reflectivity.
      GEOMED  - The geometrically corrected version of the calibrated
                image.

      All images and binary tables are provided in VICAR format, as
      defined by JPL's Multimission Instrument Processing Laboratory
      (MIPL). A VICAR file begins with an ASCII header describing the
      structure of the file. ASCII text versions of the binary tables
      are also included.

      Processing Level Id            : {2, 3, 4, 6}
      Software Flag                  : N
      Processing Start Time          : 2011-05-01
      Processing Stop Time           : 2012-05-01


      Overview of the Data Set from the Original DATASET.CAT
      ------------------------------------------------------

      NASA's Voyager Project and the Planetary Data System (PDS) have
      created an archive of planetary digital images acquired by the
      twin Voyager spacecraft (Voyager 1 and Voyager 2).  This
      initial collection includes all of the images acquired by
      Voyager 2 as it passed by the planet Uranus, and selected
      near-encounter images of Jupiter, Saturn, and their satellites
      taken by both spacecraft.

      The current Voyager archive resides on eight CDROM volumes.
      Each volume contains approximately 2500 images stored in
      individual files.  The Uranus volumes, (volumes one through
      three), store the entire image collection acquired during
      Voyager 2's encounter with Uranus.  The Saturn volumes,
      (volumes four and five), and the Jupiter volumes, (volumes six
      through eight), contain the best nearest-encounter images for
      the respective planets and their moons.

      In addition to the images, supplemental information exists on
      the CDROMs.  This includes documentation providing a user with
      information about the organization and contents of the disk.
      Software source code is included to provide programmers with
      tools to process the image files.  There are browse images,
      sub-sampled versions of the full-resolution images, which allow
      users to rapidly view the archive collection with their
      interactive display.  Finally, there are image index files
      containing information about all the images stored in the
      archive.

      The set of images on the CDROMs are raw; no processing has been
      performed other than organizing the original telemetry into
      raster-formatted files and compressing the image data using a
      Huffman encoding algorithm.  To make full scientific use of the
      image collection, it is necessary to understand the radiometric
      and geometric properties of the camera system and perform
      corrections to the data.


    Media/Format
    ============
      The archival data set is written on CD-ROM media.  The CD-ROM
      volumes conform to ISO 9660 standards.

      Processing Level Id            : 2
      Software Flag                  : N
      Processing Start Time          : 1979-02-01
      Processing Stop Time           : 1980-04-01

    Parameters
    ==========

      Data Set Parameter 'DATA NUMBER'
      --------------------------------
        Data Number is an integer expressing the digital value of each
        pixel in an image.

        Sampling Parameter Name        : PIXEL
        Data Set Parameter Name        : DATA NUMBER
        Data Set Parameter Unit        : DIMENSIONLESS

      Data Set Parameter 'PIXEL COORDINATE'
      --------------------------------
        Pixel coordinate is a real value expressing the horizontal or
        vertical location in an image. Coordinates are numbered in
        units of image pixels, beginning at one.

        Sampling Parameter Name        : PIXEL
        Data Set Parameter Name        : PIXEL COORDINATE
        Data Set Parameter Unit        : DIMENSIONLESS


    Source Instrument Parameters
    ============================
      Instrument Host ID              : VG1
      Data Set Parameter Name         : DATA NUMBER
      Instrument Parameter Name       : RADIANCE
      Important Instrument Parameters : 1


      Instrument Host ID              : VG2
      Data Set Parameter Name         : DATA NUMBER
      Instrument Parameter Name       : RADIANCE
      Important Instrument Parameters : 1


    Processing
    ==========

      Processing History
      ------------------
        Source Data Set ID          : VG1/VG2-J-ISS-2-EDR-V1.0
        Software                    : VGRCDCOPY
        Product Data Set ID         : RAW IMAGE

        Source Data Set ID          : RAW IMAGE
        Software                    : VGRFILLIN
        Product Data Set ID         : VGRFILLIN IMAGE

        Source Data Set ID          : VGRFILLIN IMAGE
        Software                    : RESLOC
        Product Data Set ID         : {RESEAU TABLE, TIEPOINT TABLE}

        Source Data Set ID          : {VGRFILLIN IMAGE, RESEAU TABLE,
                                       BLEMISH TABLE}
        Software Name               : RESSAR77
        Product Data Set ID         : RESSAR77 IMAGE

        Source Data Set ID          : RESSAR77 IMAGE
        Software Name               : DESPIKE
        Product Data Set ID         : CLEANED IMAGE

        Source Data Set ID          : {CLEANED IMAGE, DARK CURRENT
                                       IMAGE, CALIBRATION MODEL}
        Software Name               : FICOR77
        Product Data Set ID         : CALIBRATED IMAGE

        Source Data Set ID          : {CALIBRATED IMAGE, TIEPOINT
                                       TABLE}
        Software Name               : GEOMA
        Product Data Set ID         : GEOMETRICALLY CORRECTED IMAGE

      Software 'VGRCDCOPY'
      --------------------
        VICAR routine VGRCDCOPY decompresses a raw, EDR image as
        archived in PDS data set VG1/VG2-J-ISS-2-EDR-V1.0. It creates
        the RAW version of the image with a VICAR header.

        Source Data Set ID          : COMPRESSED RAW IMAGE
        Software Name               : VGRCDCOPY
        Product Data Set ID         : RAW IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'VGRFILLIN'
      --------------------
        VICAR routine VGRCDCOPY fills in incomplete lines with the
        average of the adjacent lines.

        Source Data Set ID          : RAW IMAGE
        Software Name               : VGRFILLIN
        Product Data Set ID         : VGRFILLIN IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'RESLOC'
      -----------------
        VICAR routine RESLOC locates the reseau markings within the
        Voyager image.

        Source Data Set ID          : VGRFILLIN IMAGE
        Software Name               : RESLOC
        Product Data Set ID         : {RESEAU TABLE, TIEPOINT TABLE}
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'RESSAR77'
      -------------------
        VICAR routine RESSAR77 erases reseau markings and blemishes by
        replacing them with an average of the adjacent images.

        Source Data Set ID          : {VGRFILLIN IMAGE, RESEAU TABLE,
                                       BLEMISH TABLE}
        Software Name               : RESSAR77
        Product Data Set ID         : RESSAR77 IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'DESPIKE'
      -------------------
        VICAR routine DESPIKE erases spikes in the images by
        replacing them with an average of the adjacent images.

        Source Data Set ID          : RESSAR77 IMAGE
        Software Name               : DESPIKE
        Product Data Set ID         : CLEANED IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'FICOR77'
      ------------------
        VICAR routine FICOR77 subtracts a dark current and rescales
        the image into calibrated values.

        Source Data Set ID          : {CLEANED IMAGE, DARK CURRENT
                                       IMAGE, CALIBRATION MODEL}
        Software Name               : FICOR77
        Product Data Set ID         : CALIBRATED IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

      Software 'GEOMA'
      ------------------
        VICAR routine GEOMA resamples a Voyager image to remove its
        intrinsic geometric distortion.

        Source Data Set ID          : {CALIBRATED IMAGE, TIEPOINT
                                       TABLE}
        Software Name               : GEOMA
        Product Data Set ID         : GEOMETRICALLY CORRECTED IMAGE
        Software Type               : N/A
        Software Release Date       : UNK
        Node ID                     : IMAGING
        Cognizant Engineer          : SUSAN K. LAVOIE
        Software Access Description : MIPL

Overview
    ========
      This data set represents a complete collection of images from
      Voyager 1 & 2 Saturn encounters beginning with the Observatory
      Phase.

      The image processing history represents our best understanding
      of the cameras circa the early 1990's. The programs used to
      process the images have not been updated in any significant way
      since the Voyager 2 Neptune encounter in 1989. Absolute
      calibration is probably accurate to the level of 5-10%; relative
      calibration of images through the same camera and filter is
      better. Absolute calibration of the Voyager 2 data set is
      probably somewhat more accurate due to results from the
      subsequent Uranus and Neptune encounters.

      NOTE: No calibration model is available for filters NAD (sodium)
      and CH4_JS on the Voyager 1 wide angle camera. For these images,
      the Voyager 2 models are substituted. However, the cameras have
      different gains so these images are not photometrically
      accurate in absolute terms.

      Zero values in the images are based on a dark current
      subtraction; these values are probably accurate to the level of
      a few data numbers. Comparison of reference dark current images
      taken close in time can be used to estimate the systematic
      variations.