<h2> Pioneer Venus Orbiter Ephemeris data at AMDA </h2>


<UL>
  <li> Pioneer Venus Orbiter Ephemeris data are taken from the PDS (Planetary Data System) 
    <a href="http://ppi.pds.nasa.gov/index.jsp" TARGET=_BLANK>site</a>

  <li> Available parameters :
    <UL>
      <li> <b>xyz_vso</b> : PVO spacecraft position in Venus Solar Orbital Coordinates (VSO): X is taken to be positive in the direction of the Sun measured along the Venus- Sun line. Y is taken to be positive in the direction opposing orbital motion (dusk) and lying in the orbital plane of Venus. Z is taken to be parallel to the pole of the Venus orbital plane and positive in the northward direction (upward normal). The units are given in Venus Radii where Rv = 6050 km.
      <li> <b>r</b> : Venus - Spacecraft range. 
      <li> <b>altitude</b> : Spacecraft Altitude above the Venus surface. This value is computed by subtracting 6050 km from the centered Venus-to-PVO range given in the SEDR.
      <li> <b>solar_zenith_angle</b> : This is the three body angle Sun-Venus-PVO taken from the SEDR.
      <li> <b>lon</b> : Venus centered longitude.
      <li> <b>lat</b> : Venus centered latitude.
      <li> <b>xyz_spin_axis_vso</b> : Spin axis coordinates in VSO coordinates.
      <li> <b>celestial_lon</b> : Heliocentric Celestial Latitude  of the PVO spacecraft.
      <li> <b>celestial_lat</b> : Heliocentric Celestial Longitude of the PVO spacecraft.
      <li> <b>celestial_lon_earth</b> : Heliocentric Celestial Longitude of the Earth.
      <li> <b>r_sun</b> : Sun - Spacecraft range.
    </UL>

  <li> 
    <TABLE BORDER CELLPADDING=5>
      <TR>
         <TH align="center"> Source </TH>
         <TH align="center"> Datasets </TH>
         <TH align="center"> Status </TH>
         <TH align="center"> Last Update </TH>
       </TR>
       <TR>
         <TD> <a href="http://ppi.pds.nasa.gov/search/view/?f=yes&id=pds://PPI/PV01_0001/" TARGET=_BLANK>PV01_0001</a> - ... - 
              <a href="http://ppi.pds.nasa.gov/search/view/?f=yes&id=pds://PPI/PV01_0068/" TARGET=_BLANK>PV01_0068</a></TD>
         <TD> orbit </TD>
         <TD> Certified </TD>
         <TD> 2012-11-20 </TD>
       </TR>
     </TABLE>
</UL>