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                                   PVMOV
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  Not accessible thru the PDS catalog system-Contact Node.

  This program is run at the University of California, Los Angeles.
  It reads the EDR tape and makes a set of disk files containing the
  OMAG and OEFD data. It also reads the SEDR tape and makes a disk
  file containing the ephemeris data, the pulse time data, and the
  selected roll reference (SRR or SR14) data. The software is no accessible
  through the PDS catalog system - contact Node.

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                                   PVO
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  Not accessible thru the PDS catalog system-Contact Node.

  PVO is a C-shell script which calls a series of Fortran programs
  in which process the OMAG, OEFD and Ephemeris data files.
  It reads a set of input files created by the program PVMOV,
  and generates a set of output files. 

  For the Magnetometer, the  process of converting the raw sensor
  data to orthogonal vector components includes the following steps: 

    1. Remove the average of the T sensor, computed over an integral
       number of spin periods.  The spacecraft spin period information
       is contained in the PVO Supplemental Experimenter Data Record.
    2. Convert the sensor data to orthogonal components using a
       coupling matrix, whose elements are calculated, to first order,
       from the physical orientation of the sensors.
    3. The coupling matrix and spacecraft interference parameters are 
       adjusted by monitoring any DC amplitude and the relative phase
       and amplitude of the spin plane components, and any spin period
       modulation of the spin-aligned component.
    4. The amplitude of the transverse waves in the interplanetary
       medium is much greater than that of compressional waves, and so
       the amplitude of the magnetic field remains roughly constant
       when the field direction changes.  This behavior was used to
       determine the zero level of the magnetometer, which was found
       to be Zoff = (.13 nT - .005 nT / year) for the years 1979-1984.


       Approximate values and ranges of the magnetometer parameters:

       T sensor offset: 2.5 nT +- 1 nT
       Spacecraft field contribution to G sensor:  3 nT +- 1 nT
       G sensor offset: -10nT +- 2 nT after orbit 2205, Dec 18, 1984
       P sensor offset:  .13nT - .005 nT/year

      T and G sensors have not been functioning after orbit 3602,
      Oct 16, 1988.

      We have attempted to determine the spin plane components of the
      magnetic field from this data, at one hour resolution, using an
      observed tilt of .14 degrees of the P sensor away from the spin
      axis. However, this technique has possible problems such as
      errors from a wondering spin axis relative to the geometric 
      axis.

  For the Electron Field Detector (OEFD), the data processing steps
  are:

     1. Convert the eight bit digitized output from the Automatic
        Gain Controllers (range 0 to 255) to an AGC voltage (range
	0 to 5V) for each channel.
     2. Convert the AGC voltage to a wave amplitude in V/m/root(Hz)
	using preflight calibration data for each channel. 
     3. Convert the wave amplitude to a power (amplitude squared)
	if it's required.
     4. Use the spacecraft orientation information to calculate the
	antenna phase for each channel.  The phase is corrected for
	difference in  sampling times.


  For the Ephemeris data the processing steps are:

     1. Read in the raw ephemeris file created by PVMOV which contains
        the entire ephemeris data portion of the SEDR and extract the
        following components:
           (8)     is the distance from the sun to the spacecraft.
           (11)    is the celestial lat. of the spacecraft, in degrees.
           (12)    is the celestial long. of the spacecraft, in degrees.
           (13)    is the celestial lat. of earth.
           (14)    is the celestial long. of earth.
           (32-34) are Venus-spacecraft radius vector
           (63-65) are the spin axis X Y Z in spacecraft centered 
                   non-rotating coordinates
           (92-94) are the solar position wrt Venus.
           (95-97) are the solar velocity wrt Venus.

     2. Convert Venus-spacecraft range to altitude by subtracting 6050 <km>
        and the Sun-spacecraft rage to A.U. by dividing by 149,674,000 <km>

     3. Construct a VSO rotation matrix from the solar position and velocity
        of Venus

     4. Rotate the Venus-Spacecraft and spin axis vectors into VSO coordinates