File: AAREADME.TXT                          Version: NSSDC 11/15/2001 JFC
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This directory group includes interplanetary solar wind measurements made 
by the Pioneer Venus Orbiter (aka Pioneer 12) spacecraft enroute to, and 
in orbit around, the planet Venus from 1978 until atmospheric entry in 
Oct. 1992. The two phases of the mission include (1) interplanetary cruise 
to Venus (March to Dec., 1978) and (2) Venus orbit (Dec. 1978 to Oct. 
1992). Interplanetary solar wind data were acquired during both phases, 
including outside the planetary bow shock when in orbit. Data transmission 
ceased on Oct. 8, 1992. The PVO mission and spacecraft are briefly 
described in file PVO_NMC, which contains information from the NSSDC 
Master Catalog.

Directory  Description
---------  ---------------

MAG        Triaxial Fluxgate Magnetometer (OMAG), UCLA
           Hourly averaged interplanetary field outside planetary bow 
           shock.

PLASMA     Solar Wind Plasma Analyzer (OPA), NASA Ames Research Center
           Hourly and high resolution data, plus spacecraft ephemeris 
           data, for cruise and orbit phases of mission.

MERGED     Merged hourly average solar wind plasma and magnetic field 
           data along with heliocentric coordinates of Venus

TRAJ       Heliocentric coordinates of Venus from NSSDC's Satellite 
           Situation Center (SSC)


Related Information and Data:

Further details on the spacecraft, experiment, data sets at NSSDC, and 
related WWW sites can be found on the Pioneer Venus flight project page:

http://nssdc.gsfc.nasa.gov/space/

Hour averages of the interplanetary solar wind data from, and hourly 
heliocentric coordinates of, Pioneer Venus and other interplanetary 
spacecraft may be also be accessed and plotted on-line through the 
COHOWeb service based at the same WWW site as above.

Acknowledgement:

Use of these data in publications should be accompanied at minimum by
acknowledgements of the National Space Science Data Center and the 
responsible Principal Investigator defined in the experiment 
documentation provided here.