Data Set Overview
      =================
 
      Data Set Description
      --------------------
      This data set consists of Voyager 2 Saturn encounter ephemeris data
      in Kronographic (L1) coordinates covering the period 1981-08-23 to
      1981-08-29. 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 2 SEDR, the other
      by the PDS/PPI node using the VG1_SAT.TSP and PCK00006.TPC SPICE
      kernels.
 
      Due to inaccuracies in Voyager SEDR, as well as changes in the
      values of some key parameters (e.g. Saturnian radius) the timing
      is improved for the SPICE generated data. However, since much
      of the original analysis was based upon the SEDR generated
      ephemeris, this data has been included as well.
 
      SEDR generated ephemeris
      ------------------------
      Instrument P.I.       : N/A
      Data Supplier         : NSSDC
      Data sampling rate    : 96 seconds
      Data Set Start Time   : 1981-08-23T10:34:23.645Z
      Data Set Stop Time    : 1981-08-29T23:57:35.078Z
 
      SPICE generated ephemeris
      -------------------------
      Instrument P.I.       : N/A
      Data Supplier         : S. Joy
      Data sampling rate    : 96 seconds
      Data Set Start Time   : 1981-08-23T10:34:23.645Z
      Data Set Stop Time    : 1981-08-29T23:57:35.078Z
 
      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]         kronocentric (L1) cartesian
      sc_y       R[J]         cartesian position vectors: X, Y, and
      sc_z       R[J]         Z
 
      vel_x      km/s         kronocentric (L1) X, Y, and Z spacecraft
      vel_y      km/s         velocity components
      vel_z      km/s
 
      sc_r       R[J]         kronocentric (L1) spherical
      sc_lat     degrees      coordinates position vectors: range,
      sc_lon     degrees      latitude, and longitude
 
      CartSys3_to_SphSys3     cartesian L1 coordinates to spherical L1
                              coordinates rotation matrix containing
                              9 1pe15.8 elements
 
      SC_to_CartSys3          payload (spacecraft) to cartesian L1
                              coordinates rotation matrix containing
                              9 1pe15.8 elements
 
      SC_to_SphSys3           payload (spacecraft) to spherical L1
                              coordinates rotation matrix containing
                              9 1pe15.8 elements
 
      SPICE 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
 
      R          AU           kronocentric (L1) spherical coordinates
      LAT        degrees      range, latitude, and longitude position
      LON        degrees
 
      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 Kronographic (L1) coordinates is a Saturn centered spherical
      system, based on the Saturn Longitude System (Voyager Measurements
      of the Rotation Period of Saturn's Magnetic Field, Desch and Kaiser,
      JGR, 8, 253, 1981).  In this coordinate syatem, longitude increases
      with time as viewed by a stationary remote observer.
 
      In cartesian coordinates:
      X      points along the Saturn-Sun line in the solar
             equatorial plane (positive towards the Sun)
 
      Y      completes the right handed set
 
      Z      points along the Saturn's spin axis, positive
 
      In spherical coordinates:
      R      Saturn to spacecraft range (positive away from
             Saturn)
 
      LAT    completes the left handed, orthogonal set
 
      LON    east longitude (with longitude increasing eastward
             from a specific Saturnian prime meridian)
 
      SPICE ephemeris were generated using the current definition of
      the Saturnian radius, 60268 km. The spin rate used in generating
      these data is the same as that used for System III (1965),
      +870.536 degrees/24 hours.