Data Set Overview
      =================
      This data set consists of magnetic field vector data recorded by
      the Fluxgate Magnetometer on board the Pioneer 11 spacecraft,
      during the Saturn encounter period.  Data include 146 second
      averages of the magnetic field data in RK spherical coordinates
      and spacecraft trajectory data.


      Data Sampling
      ==============
      At Saturn, instantaneous vector measurements were obtained
      every 146.3 second, in synchronism with the spacecraft spin
      period of 7.7 second.


      Data Processing
      ===============
      No detailed information of data processing is found in the NSSDC
      documentation pertinent to this data set.

      Pioneer 11 spacecraft was operating under a spin-stablized
      condition and had a spin period of 7.7 second.


      Data Format
      ============
      The Pioneer 11 magnetometer data for Saturn encounter were
      originally written on an ASCII magnetic tape.  The original
      file was re-formatted into a new ASCII file named
      P11_FGM_SAT_ENC_146SEC.TAB which contains the following data columns:
      --------------------------------------------------------------------
      Column  Column   Column
      Name    Format   Description
      --------------------------------------------------------------------
      TIME    A24      Time in yyyy-mm-ddThh:mm:ss.sssZ
      R       F7.4     Distance of Pioneer 11 from Saturn in Rs
      LAT     F9.4     Latitude of Pioneer 11 (unknown coordinates)
      LON     F10.4    Longitude of Pioneer 11 (unknown coordinates)
      BR      F10.6    Radial component of the magnetic field in
                           RK coordinates
      BTHETA  F10.6    Polar component of the magnetic field in
                           RK coordinates
      BPHI    F10.6    Azimuthal component of the magnetic field in
                           RK coordinates
      --------------------------------------------------------------------


      Coordinate System for Data
      ===========================
      RK coordinates is based on two principle directions, Saturn to
      Pioneer 11, R, and Saturn spin axis, J.  X=R points away from
      Saturn.  Y is a vector in the direction of J cross R.  Z is X
      cross Y.  Radial direction R, points away from Saturn, polar
      direction THETA, positive northward, and azimuthal direction,
      PSI, parallel to the X-Y plane, positive eastward.

      The NSSDC documentation associated with this data set doesn't
      provide information on the coordinate system used for spacecraft
      trajectory data.


      Ancillary Data
      ==============
      There is no ancillary data associated with this data set.


      Instrument Calibration
      ======================
      The fluxgate magnetometer was calibrated at the GSFC Magnetic
      Test Facility by means of a 2 meter diameter, single axis
      Helmholtz coil system.  Typically hysteresis observed after
      exposure to 2.5 mT fields was less than 1 part in 10**3 (one
      count).  Temperature stability is better than +- 0.5% over the
      temperature range of -20 to +40 degree Celsius in spite of the
      open loop design of the instrument.  This is due to the fact
      that the characteristics of the magnetic material used in the
      sensor cores are fairly independent of temperature over the
      indicated range.  The stability figure includes the A/D converter
      drift and a large portion of it is due to the single ramp design
      of the latter.  Nevertheless, minimum power consumption
      requirements and flight qualified component availability
      precluded the used of more stable A/D converter designs
      (ACUNA&NESS1974).

Confidence Level Overview
      =========================
      No data confidence information is found in the NSSDC documentation
      pertinent to this data set.

      There is no flagged values in this data set.