Data Set Overview
  =================

    Version 1.1
    -----------
      The SEDR based data provided as part of this data set were
      originally reviewed and archived with the NSSDC and PDS as
      version 1.0 (DATA_SET_ID = VG1-J-POS-4-48.0SEC).  Version 1.1
      includes additional columns not present in the previous
      version, 96 second rather than 48 second time samples, times
      converted to 'PDS Style' or ISO standard, and upgrading of
      PDS labels and templates to version 3.2.  The SPICE based
      data that are also part of this data set were not previously
      archived with the PDS.  This version 1.1 data set replaces
      previously archived versions.


    Data Set Description
    --------------------
      This data set consists of Voyager 1 Jupiter encounter
      ephemeris data in System III (1965) left handed coordinates
      covering the period 1979-03-03 to 1979-03-16.  Two versions,
      both covering the same time period, but containing slightly
      different data, are provided.  One version was generated by
      the Voyager MAG team from Voyager 1 SEDR, the other by the
      PDS/PPI node using the VG1_JUP.BSP and PCK00003.TCP SPICE
      kernels.

      Two versions of the spacecraft ephemeris data are provided as
      an attempt to correct some of the problems in the Voyager
      SEDR while preserving the ability to reproduce early results.
      The original SEDR data has a variety of problems which may
      affect the knowledge of the spacecraft position, or
      conversely, the timing associated with certain events such as
      ring plane crossings.  The SPICE SPK kernel provided on this
      disk includes corrections to some, but not all, of the
      problems associated with the Voyager SEDR.  The Navigation
      and Ancillary Information Facility (NAIF) at JPL may issue a
      new Voyager SPK kernel in the future that will further
      improve the knowledge of the spacecraft location in inertial
      space.

      There are other differences in the in the two versions of
      ephemeris data that are the result of improvements in the
      knowledge of some of the physical constants associated with
      Jupiter and its moons.  Since the Voyager era, there have
      been updates to the orientation of the jovian spin axis right
      ascension and declination, the radius of Jupiter, as well as
      the orbital characteristic and other physical parameters of
      many of the moons of Jupiter.  These changes affect the
      stated position of the spacecraft in jovigraphic coordinate
      systems like System III without changing the position of the
      spacecraft in inertial space.  The spin rate of Jupiter is
      not changed from the System III (1965) rate of 9h 55m
      29.71sec (870.536 deg/day).  The SPICE planetary constants
      kernel (PCK) contains both the current IAU definitions of the
      physical constants for the bodies within in the jovian system
      (as data) as well as the older IAU definitions (as comments).
      This is an ASCII text file (PCK00003.TCP) and users of the
      ephemeris data are encouraged to review it.


    SEDR generated ephemeris
    ------------------------
      Instrument P.I.       : N/A
      Data Supplier         : NSSDC (Voyager MAG Team)
      Data sampling rate    : 96 seconds
      Data Set Start Time   : 1979-03-03T00:00:35.978Z
      Data Set Stop Time    : 1979-03-16T23:59:08.185Z


    SPICE generated ephemeris
    -------------------------
      Instrument P.I.       : N/A
      Data Supplier         : S. Joy
      Data sampling rate    : 48 seconds
      Data Set Start Time   : 1979-03-03T00:00:35.978Z
      Data Set Stop Time    : 1979-03-16T23:59:56.185Z


  Parameters
  ==========

    SEDR generated ephemeris
    ------------------------
      PARAMETER  RESOLUTION/  DESCRIPTION
      NAME       UNITS

      time       96.0 Sec     time of the sample (UT) in the format
                               yyyy-mm-ddThh:mm:ss.sssZ

      m65536     counts       spacecraft clock counts
      mod60      counts
      fds_line   counts

      sc_x       R[J]         jovicentric (System III) cartesian
      sc_y       R[J]         cartesian position vectors: X, Y, and
      sc_z       R[J]         Z

      vel_x      km/s         jovicentric X, Y, and Z spacecraft
      vel_y      km/s         velocity components
      vel_z      km/s

      sc_r       R[J]         jovicentric (System III) spherical
      sc_lat     degrees      coordinates position vectors: range,
      sc_lon     degrees      latitude, and longitude

      CartSys3_to_SphSys3     cartesian system III to spherical
                              system III coordinates rotation matrix
                              containing 9 1pe15.8 elements

      SC_to_CartSys3          payload (spacecraft) to cartesian
                              system III coordinates rotation matrix
                              containing 9 1pe15.8 elements

      SC_to_SphSys3           payload (spacecraft) to spherical
                              system III coordinates rotation matrix
                              containing 9 1pe15.8 elements


    SPICE generated ephemeris
    -------------------------
       PARAMETER  RESOLUTION/  DESCRIPTION
       NAME       UNITS

       time       48.0 Sec     time of the sample (UT) in the
                               format yyyy-mm-ddThh:mm:ss.sssZ

       R          Rj           jovicentric (System III 1965)
       LAT        degrees      spherical coordinates position
       LON        degrees      range, latitude, and longitude

       LocTime    hours        angular separation between the
                               meridian containing the sun and the
                               one containing the spacecraft
                               converted to a time. The sun meridian
                               is defined to be noon (12.000), with
                               midnight (0.000) opposite it. Dawn
                               (6.000) and dusk (18.000) are where
                               the sun rises and sets according to
                               the planet's rotation


  Coordinate System
  =================
    The System III (1965) is a jovicentric left handed coordinate
    system defined such that longitude increases with time as
    viewed by a stationary remote observer.

           Jovicentric cartesian (Jupiter fixed) coordinates

    X      points along the Jupiter-Sun line in the solar
           equatorial plane (positive towards the Sun)

    Y      completes the right handed set

    Z      points along the jovian spin axis, positive

           Jovicentric System III (1965) spherical coordinates

    R      Jupiter to spacecraft range (positive away from
           Jupiter)

    LAT    completes the left handed, orthogonal set

    LON    System III (1965) east longitude (with longitude
           increasing eastward from a specific jovian prime
           meridian)

    SPICE ephemeris were generated using the current definition of
    the Jovian radius, 71492 km.  The spin rate used in generating
    these data is the same as that used for System III (1965),
    +870.536 degrees/24 hours.


  Data Coverage
  =============

    Filename Records Start                     Stop
    -------------------------------------------------------------------
    SEDR062  1623    1979-03-03T00:00:35.978Z  1979-03-04T23:58:59.925Z
    SEDR064  6071    1979-03-05T00:00:35.925Z  1979-03-11T23:59:08.059Z
    SEDR071  4370    1979-03-12T00:00:44.059Z  1979-03-16T23:59:08.185Z
    SPICE062 3246    1979-03-03T00:00:35.978Z  1979-03-04T23:59:47.925Z
    SPICE064 12142   1979-03-05T00:00:35.925Z  1979-03-11T23:59:56.059Z
    SPICE071 8740    1979-03-12T00:00:44.059Z  1979-03-16T23:59:56.185Z

Confidence Level Overview
  =========================

    SPICE generated ephemeris
    -------------------------
      The SPICE generated data were derived from SPICE using
      software that has been extensively tested.  They should give
      as accurate representation of spacecraft ephemeris as
      possible using these kernels.

      Comparisons between these data and other data from previous
      Jupiter missions should be performed with caution.  Some key
      parameters, such as the Jovian radius, have changed from
      mission to mission.  Definitions for Jupiter's spin rate and
      the orientation of its spin-axis have also changed slightly
      since the pre-Voyager days.


  Missing Data Flag
  =================
    Any SEDR generated ephemeris data column whose value is
    -9.99999999e+10 is a missing data value.